Environ Toxicol Chem, 2004 Dec, 23(12), 2799 - 806 Bacterial energetics, stoichiometry, and kinetic modeling of 2,4-dinitrotoluene biodegradation in a batch respirometer; Zhang C et al.; A stoichiometric equation and kinetic model were developed and validated using experimental data from batch respirometer studies on the biodegradation of 2,4-dinitrotoluene (DNT) . The stoichiometric equation integrates bacterial energetics and is revised from that in a previous study by including the mass balance of phosphorus (P) in the biomass . Stoichiometric results on O2 consumption, CO2 evolution, and nitrite evolution are in good agreement with respirometer data . However, the optimal P requirement is significantly higher than the stoichiometrically derived P, implying potentially limited bioavailability of P and the need for buffering capacity in the media to mitigate the adverse pH effect for optimal growth of DNT-degrading bacteria . An array of models was evaluated to fit the O2/CO2 data acquired experimentally and the DNT depletion data calculated from derived stoichiometric coefficients and cell yield . The deterministic, integrated Monod model provides the goodness of fit to the test data on DNT depletion, and the Monod model parameters (Ks, X0, mumax, and Y) were estimated by nonlinear regression . Further analyses with an equilibrium model (MINTEQ) indicate the interrelated nature of medium chemical compositions in controlling the rate and extent of DNT biodegradation . Results from the present batch respirometer study help to unravel some key factors in controlling DNT biodegradation in complex remediation systems, in particular the interactions between acidogenic DNT bacteria and various parameters, including pH and P, the latter of which could serve as a nutrient, a buffer, and a controlling factor on the bioavailable fractions of minerals (Ca, Fe, Zn, and Mo) in the medium. J Biotechnol, 2005 Feb 23, 115(4), 367 - 77 Epub 2004 Dec 09. Polycyclic aromatic hydrocarbon biodegradation in extracellular fluids and static batch cultures of selected sub-tropical white rot fungi; Tekere M et al.; Four sub-tropical white rot fungi, Trametes versicolor, Trametes pocas, Trametes cingulata and isolate DSPM95 were studied alongside the well studied white rot fungus, Phanerochaete chrysosporium, for their ability to remove polycyclic aromatic hydrocarbons (PAHs) from culture media . Both static shallow cultures and extracellular fluids were studied using media contaminated with a defined mixture of the PAHs; fluorene, phenanthrene, anthracene, pyrene and benzo(a)anthracene . With all isolates, the total loss of the parent compound in 31days was high for fluorene, at +60%, phenanthrene at +40% and anthracene at +42% . Biotransformation of pyrene and benzo(a)anthracene by all the isolates was low, with the highest reduction of pyrene of 15.2% and benzo(a)anthracene of 15.8% being achieved with P . chrysosporium . Disappearance of the more condensed PAHs, pyrene and benzo(a)anthracene, increased in shallow static cultures with the addition of glucose and glucose oxidase as a source of additional H(2)O(2) . The addition of Mn(2+) and ABTS (2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid)) to culture supernatants was associated with higher levels of biotransformation . Comparison of the isolates T . versicolor, T . pocas, T . cingulata and isolate DSPM95 with P . chrysosporium showed that these strains were competitive in the reduction of the PAHs, reducing the PAHs by more or less the same magnitude . Also these sub-tropical isolates did not accumulate a lot of HPLC detectable metabolites as much as P . chrysosporium. Biomacromolecules, 2005 Jan-Feb, 6(1), 1 - 8 Bacterial polyesters: biosynthesis, biodegradable plastics and biotechnology; Lenz RW et al.; The discovery and chemical identification, in the 1920s, of the aliphatic polyester: poly(3-hydroxybutyrate), PHB, as a granular component in bacterial cells proceeded without any of the controversies which marked the recognition of macromolecules by Staudinger . Some thirty years after its discovery, PHB was recognized as the prototypical biodegradable thermoplastic to solve the waste disposal challenge . The development effort led by Imperial Chemical Industries Ltd., encouraged interdisciplinary research from genetic engineering and biotechnology to the study of enzymes involved in biosynthesis and biodegradation . From the simple PHB homopolyester discovered by Maurice Lemoigne in the mid-twenties, a family of over 100 different aliphatic polyesters of the same general structure has been discovered . Depending on bacterial species and substrates, these high molecular weight stereoregular polyesters have emerged as a new family of natural polymers ranking with nucleic acids, polyamides, polyisoprenoids, polyphenols, polyphosphates, and polysaccharides . In this historical review, the chemical, biochemical and microbial highlights are linked to personalities and locations involved with the events covering a discovery timespan of 75 years. Coll Antropol, 2004 Jun, 28(1), 331 - 6 Efficiency of polylactide/polyglycolide copolymers bone replacements in bone defects healing measured by densitometry; Katanec D et al.; Healing of bone defects is the most frequent cause of failure in surgical treatments of an odontogenic ostitic processes . The aim of this study was to determine successfulness in healing of bone defects after implantation of alloplastic co-polymer-polyglycol bone implant . A group of 45 cases with periradicular ostitic processes were examined . The densitometric measurements were taken from radiovisiographic dental x-ray images . Patients were observed throughout a period of one year . The results obtained were analyzed and presented graphically . Thirty-eight patients (84%) were treated successfully, and seven patients (16%) showed unsuccessful healing of the bone defects . The results obtained indicate that polyglycol copolymer bone implants can be successfully used in a treatment of odontogenically caused bone defects . Their fundamental advantage is a slow biodegradation, which ensures a more suitable area for the apposition of a new bone in the defect, simple application in clinical work and the possibility of a mutual combination of all three available forms. Macromol Biosci, 2005 Jan 14, 5(1), 49 - 57 Investigation of fungal deterioration of synthetic paint binders using vibrational spectroscopic techniques; Cappitelli F et al.; The deterioration of synthetic polymers caused by biological process is usually evaluated by visual inspection and measuring physical effects . In contrast to this approach, we have applied vibrational spectroscopies to study the biodegradation of the synthetic resins . 29 synthetic resins used as paint binding media, including acrylic, alkyd and poly(vinyl acetate) polymers, were examined for potential susceptibility to fungal degradation using the standard method ASTM G21-96(2002) . In addition, the degraded resins were analysed by Raman spectroscopy, FT-IR and FT-IR photoacoustic spectroscopy . Almost all the acrylic resins studied proved to be resistant to microbial attack, while all alkyd resins and some poly(vinyl acetates) turned out to be biodegradable . Within a few days of inoculation Aspergillus niger was the most copious fungus on the biodegraded resins . A comparison of the IR and Raman spectra of control and biodegraded resins did not show any differences, but photoacoustic spectroscopy revealed additional bands for the fungal-degraded resins, consistent with the presence of fungal-derived substances . The additional bands in the photoacoustic spectra were due to the presence of Aspergillus niger and melanin, a fungal pigment . Since IR photoacoustic spectroscopy can be also a suitable technique for the chemical characterisation of binding media, the same spectroscopic analysis can be employed to both characterise the material and obtain evidence for fungal colonization.Microbial growth on Sobral 1241ML (alkyd resin) after 28 d (growth rating 4) compared with the non-inoculated resin. Proc Natl Acad Sci U S A . 2005 Jan 4; {Epub ahead of print} Enantioselectivity in environmental safety of current chiral insecticides; Liu W et al.; Chiral pesticides currently constitute about 25% of all pesticides used, and this ratio is increasing as more complex structures are introduced . Chirality occurs widely in synthetic pyrethroids and organophosphates, which are the mainstay of modern insecticides . Despite the great public concerns associated with the use of insecticides, the environmental significance of chirality in currently used insecticides is poorly understood . In this study, we resolved enantiomers of a number of synthetic pyrethroid and organophosphate insecticides on chiral selective columns and evaluated the occurrence of enantioselectivity in aquatic toxicity and biodegradation . Dramatic differences between enantiomers were observed in their acute toxicity to the freshwater invertebrates Ceriodaphnia dubia and Daphnia magna, suggesting that the aquatic toxicity is primarily attributable to a specific enantiomer in the racemate . In field sediments, the (-) enantiomer of cis-bifenthrin or cis-permethrin was preferentially degraded, resulting in relative enrichment of the (+) enantiomer . Enantioselective degradation was also observed during incubation of sediments under laboratory conditions . Enantioselectivity in these processes is expected to result in ecotoxicological effects that cannot be predicted from our existing knowledge and must be considered in future risk assessment and regulatory decisions. Biomaterials, 2005 Jun, 26(18), 3881 - 9 Phospholipase A(2) pathway association with macrophage-mediated polycarbonate-urethane biodegradation; Dinnes DL et al.; Activation of the phospholipase A(2) (PLA(2)) pathway is a key cell signaling event in the inflammatory response . The PLA(2) family consists of a group of enzymes that hydrolyze membrane phospholipids, resulting in the liberation of arachidonic acid (AA), a precursor to pro-inflammatory molecules . Given the well-documented activating role of biomaterials in the inflammatory response to medical implants, the present study investigated the link between PLA(2) and polycarbonate-based polyurethane (PCNU) biodegradation, and the effect that material surface had on PLA(2) activation in the U937 cell line . PCNUs were synthesized with poly(1,6-hexyl 1,2-ethyl carbonate)diol, 1,4-butanediol and one of two diisocyanates (hexane 1,6-diisocyanate or 4,4'-methylene bisphenyl diisocyanate) in varying stoichiometries and incubated with adherent U937 cells . PLA(2) inhibiting agents resulted in significantly decreased PCNU biodegradation (p<0.05) . Moreover, when activation of PLA(2) was assessed ((3)H-AA release), significantly more (3)H-AA was released from PCNU-adherent U937 cells than polystyrene-adherent U937 cells (p<0.05) which was significantly decreased in the presence of PLA(2) inhibitors . The pattern of inhibition of U937 cell-mediated biodegradation and (3)H-AA release that was modulated by PCNU surface differences, suggests a role for secretory PLA(2) along with cytosolic PLA(2) . Understanding PCNU activation of intracellular pathways, such as PLA(2), will allow the design of materials optimized for their intended use. Biomed Mater Eng, 2005, 15(1-2), 73 - 85 Design of oligolactone-based scaffolds for bone tissue engineering; Vogt S et al.; Novel difunctional oligolactone macromers have been synthesized by ring-opening oligomerization of various lactones (L-lactide, glycolide, p-dioxanone) in the presence of suitable diols (propane-1,2-diol, dianhydro-D-glucitol) and subsequent endcapping of the formed oligolactones with methacrylate moieties . Based on these macromers, two fabrication procedures were developed to fabricate highly porous scaffolds and the material properties including in vitro biodegradation behaviour of the resulting polymeric scaffolds were investigated . Preliminary in vitro studies on the cytocompatibility of the fabricated scaffolds and on osteoblast cultivation on the optimized polymeric materials demonstrated that the oligolactide based polymer networks possess an excellent biocompatibility and that they are promising candidates as scaffolds in bone tissue engineering. Biomed Mater Eng, 2005, 15(1-2), 65 - 71 The effect of choice of sterilisation method on the biocompatibility and biodegradability of SIS (small intestinal submucosa); Grimes M et al.; SIS (small intestinal submucosa) is a 3D extracellular matrix (ECM) material of porcine origin . It has a complex composition predominantly composed of collagen type I . SIS is rapidly absorbed, supports early and abundant new vessel growth, and serves as a template for the reconstructive remodelling of several body tissues . Currently SIS products are sterilised using ethylene oxide, gamma irradiation and e-beam irradiation . It is not known how they affect the materials properties such as structure, mechanical strength and biocompatibility . This study investigated the influence of each sterilisation method on the biocompatibility and biodegradation of SIS using L929 mouse fibroblasts . SIS samples were sterilised by each of the above methods under standard conditions . The samples were subjected to hydrolytic degradation conditions for specific periods of time . All sterilisation methods resulted in an increase in the rate of sample degradation . The study indicated that over time e-beam irradiation caused the greatest % weight loss . Applying sample extracts to L929 mouse fibroblasts assessed the biocompatibility of the degradation products . The % cellular protein and % metabolic activity were then assessed using the BCA assay and MTT assay, respectively . All SIS samples caused an increase in both cellular protein production and metabolic activity . Initially samples sterilised by ETO had the greatest effect but this decreased after 28 days . Unsterile samples were found to have a slower more prolonged influence . It is thought that the components released may include extractable growth factors and further studies are required to confirm this. Huan Jing Ke Xue, 2004 Sep, 25(5), 172 - 6 {Biodegradation characteristics of organic compounds in leachate in electrochemical oxidation and anaerobic process combined treatment system}; Li TG et al.; Degradation characteristics of typical organic compounds in landfill leachate were investigated by electrochemical oxidation and anaerobic process combined treatment system in this paper . In electrochemical oxidation system, degradation rate of polyphenolic, polyamide, benzothiazole, benzoquinone, quinoline and naphthalene compounds was higher than that of Exo-2-hydroxycineole and isoquinoline compounds, but that of the former was lower in anaerobic process . After electrochemical oxidation process, content of Volatile Fatty Acids (VFAs) markedly increased from 0.68% of raw leachate to 16.18% of effluent of electrochemical reactor . The results indicate that synergetic and antagonistic effects of complicated components on biotoxicity in leachate are notably decreased in such the combined treatment system, and biodegradability of systemic effluent is improved . These are key reasons to highly effectively treat landfill leachate by using such the combined treatment system, and can provide technical assistance to further investigate treatment technology of landfill leachate and large-scale development of electrochemical oxidation and anaerobic process combined treatment system. Huan Jing Ke Xue, 2004 Sep, 25(5), 133 - 7 {Isolation and identification of two marine bacteria with hydrocarbon-biodegradation activity}; Shao ZZ et al.; Two bacterial strains, able to degrade both diesel fuel and PAHs, were isolated from the oil sewage of oil storage dock in Xiamen . Analysis of 16S rDNA sequences showed that both strains had high homology (99%) with Pseudomonas stutzeri and should be classified to this species . But Biolog analysis showed they were quite different strains . Tests of temperature, salinity, pH on cell growth suggested that they were from marine environment . Both showed high degradation activity to naphthalene, 87.53% and 84.01% within 3 days; and slight activity to pyrene, 8.35% and 5.37% within 7 days . And both harbored naphthalene dioxygenase genes of 98% identity with other those from Pseudomonas strains. Isotopes Environ Health Stud, 2004 Dec, 40(4), 243 - 56 Long term changes in the distribution and delta(15)N values of individual soil amino acids in the absence of plant and fertiliser inputs; Bol R et al.; The long-term 'biodegradation' on soil amino acids was examined in the control plots of '42 parcelles' experiment, established in 1928 at INRA, Versailles (France) . None of the plots is cultivated, but is kept free of weeds, and mixed to a depth of 25 cm twice yearly . Topsoil (0-10 cm depth) samples collected in 1929, 1963 and 1997 were subjected to acid hydrolysis (6 N HCl) for comparison . The distribution and delta(15)N natural abundance of 20 individual amino acids in the soils were determined, using ion chromatography (IC) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) . The total N and amino acid-N (AA-N), respectively, decreased by 54 % and 73 % in the period from 1929 to 1997 . The average N loss was comparable for 1929-1963 (period 1) and 1963-1997 (period 2), but AA-N loss was three times faster in the former period . This significant reduction in total AA-N content was mirrored in the individual amino acids, which decreased by 74 % +/- 1 % (ranging 58-89 %) between 1929 and 1997 . The bulk delta(15)N values generally increased from 1929 to 1997, mainly associated with comparable or even higher increase of delta(15)N of the non-AA-N in the soil . The residence time (t(1/2), time in which half of N was lost from a specific soil pool) was ca . 65 +/- 5 years for the bulk soil, and comparable for periods 1 and 2 . However, between periods 1 and 2 it decreased from 128 to 41 years in the non-AA pool, but increased from 59 to 92 years in the AA-N pool . Proline and amino acids that appear early in soil microbial metabolic pathways (e.g . glutamic acid, alanine, aspartic acid and valine) had relatively high delta(15)N values . Phenylalanine, threonine, glycine and leucine had relatively depleted delta(15)N values . The average delta(15)N value of the individual amino acids (IAAs) increased by 1delta unit from 1929 to 1997, associated with a similar rise from 1929 to 1963, and no change thereafter till 1997 . However, the delta(15)N values of phenylalanine decreased by more than 7delta(15)N units between 1929 and 1997 . The delta(15)N shift of IAAs from 1929 to 1963 and from 1929 to 1997 was not influenced by the relative amount of N remaining compared with the 1929 soil concentrations . The only exception was phenylalanine which showed decreasing delta(15)N associated with its decreasing concentration in the soil . We conclude therefore that in the absence of plant and fertiliser inputs, no change in the delta(15)N value of individual soil amino acids occurs, hence the original delta(15)N values are preserved and diagnostic information on past soil N (cycling) is retained . The exception was phenylalanine, its delta(15)N decreased with decreasing concentration from 1929 to 1997, hence it acted as a 'potential' marker for the land use changes (i.e . arable cropping to a fallow) . The long term biological processing and reworking of residual amino acids resulted in a (partial) stabilisation in the soil, evidenced by reduced N loss and increased residence time of amino acid N during the period 1963-1997. Chemosphere, 2005 Jan, 58(4), 407 - 16 Bioregeneration of powdered activated carbon in the treatment of alkyl-substituted phenolic compounds in simultaneous adsorption and biodegradation processes; Lee KM et al.; The role of bioregeneration process in renewing the adsorbent surface for further adsorption of organics during simultaneous adsorption and biodegradation processes has been well recognized . The extent of bioregeneration of powdered activated carbon (PAC) as an adsorbent loaded with phenol, p-methylphenol, p-ethylphenol and p-isopropylphenol, respectively, in the simultaneous adsorption and biodegradation processes were quantitatively determined using oxygen uptake as a measure of substrate consumption . Bioregeneration phenomenon was also evaluated in the simultaneous adsorption and biodegradation processes under sequencing batch reactor (SBR) operation to treat synthetic wastewater containing 1200mgl(-1) phenol and p-methylphenol, respectively . The SBR systems were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in the ratio of 4:6:1:0.75:0.25 for a cycle time of 12h . The results show that the percentage of desorption from loaded PAC decreased in the order phenol>p-methylphenol>p-ethylphenol>p-isopropylphenol . For the treatment of phenol and p-methylphenol in the SBR reactors, respectively, the simultaneous adsorption and biodegradation processes were able to produce a consistent effluent quality of COD 100 mgl(-1) when the applied PAC dosage was 0.115 and 0.143g PAC per cycle, respectively . When no further PAC was added, the treatment performance deteriorated to that of the case without PAC addition after 68 and 48 cycles of SBR operation, respectively, for phenol and p-methylphenol . This observation is consistent with the greater extent of bioregeneration for phenol-loaded PAC as compared to p-methylphenol-loaded PAC. J Environ Sci Health B, 2004, 39(5-6), 871 - 87 Effect of inoculating flower stalks and vegetable waste with ligno-cellulolytic microorganisms on the composting process; Lu WJ et al.; A lab-scale composting experiment was carried out using vegetable and flower stalks waste to study the effectiveness of ligno-cellulolytic microorganisms (LCMs) obtained from the previous isolation on composting process, especially on enhancement of biodegradation rate of these organic materials . The addition of LCMs to compost showed promised to be a valuable asset by rendering timely benefits in efficiency, maturity, and quality of the composting . This was evidenced by a significant increase of temperature, O2 consumption and CO2 emission, and population density of LCMs in compost mass compared with that of biotic (addition of culture of horse feces) and abiotic (1% molasses amendment) treatments, as well as control trial . The phytotoxicity assay showed that the substrate became mature after 60 days' composting . The LCMs inoculation enhanced the biodegradation of the composting materials as evidenced by an increasing screening ratio (1.2 cm sieve pore) of 34.5% in the treated trail, compared with that of control, which elucidated that big advantage of adding selected inoculants over other treatment, and screening ratio is a reasonable index to compare the quality of different compost . However, the inoculation seemed to have no significant effect on the moisture content, pH, and the final organic carbon of the composting materials. J Environ Sci Health B, 2004, 39(5-6), 757 - 64 Biodegradation of alpha and beta endosulfan in soil as influenced by application of different organic materials; Al-Hassan RM et al.; A laboratory pot experiment was conducted to study the effect of amending soil with four different sources of organic matter on the degradation rate of alpha and beta endosulfan isomers . Poultry by-product meal, poultry manure, dairy manure, and municipal solid waste compost were cured, dried, ground (<1 mm) and thoroughly mixed with a calcareous soil at a rate of 2% and placed in plastic pots . Endosulfan was added at the rate of 20 mg kg(-1) . The moisture level was kept near field capacity and the pots were kept at room temperature . Soil sub-samples, 100 g each, were collected from every pot at days 1, 8, 15, 22, 29, 43, and 57 for the measurement of endosulfan isomers . Endosulfan residues were extracted from the soil samples with acetone . The supernatant was filtered through anhydrous sodium sulphate, 5 mL aliquot was diluted to 25 mL with hexane, mixed well, and then two sub-samples from the filtrates were analyzed for alpha and beta endosulfan isomers by gas chromatography . The results indicated that the half-life (T(1/2)) of alpha-endosulfan in the poultry by-product meal treatment was 15 days compared to about 22 days in the other treatments . The T(1/2) of beta-endosulfan was 22 days in the poultry by-product meal treatment and followed a bi-phasic pattern, 57 days in the municipal solid waste compost treatment and the extrapolated T(1/2) was about 115 days for the other three treatments. J Environ Sci Health B, 2004, 39(5-6), 747 - 56 Biodegradation of trifluralin in Harran soil; Tiryaki O et al.; Degradation of trifluralin (alpha, alpha, alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) was investigated in soils taken from three different locations at Harran region of Turkey under laboratory conditions . Surface (0-10 cm) soils, which were taken from a pesticide untreated field Gurgelen, Harran-1 and Ikizce regions in the Harran Plain . were incubated in biometer flasks for 350 days at 25 degrees C . Ring-UL-14C-trifluralin was applied at the rate of 2 microg g(-1) with 78.7 kBq radioactivity per 100 g soil flask . Evolved (14)CO2 was monitored in KOH traps throughout the experiment . Periodically, soil sub-samples were removed and extracted by supercritical fluid extraction (SFE) . Unextractable soil-bound 14C residues were determined by combustion . During the 350 days incubation period 6.6, 5.4, and 3.3/' of the applied radiocarbon was evolved as (14)CO2 from the Harran-1, Gurgelen, and Ikizce soil, respectively . At the end of 350 days the SFE-extractable and bound 14C-trifluralin residues were 39.0 and 29.2% of the initially applied herbicide in Gurgelen soil . The corresponding values for Harran-1 and Ikizce soils were 36.2, 28.4% and 41.6, 18.5% respectively. Biotechnol Lett, 2004 Oct, 26(19), 1493 - 6 Biodegradation and detoxification of nicotine in tobacco solid waste by a Pseudomonas sp; Wang SN et al.; A Pseudomonas sp . grew with nicotine optimally 3 g l(-1) and at 30 degrees C and pH 7 . Nicotine was fully degraded within 10 h . The resting cells degraded nicotine in tobacco solid waste completely within 6 h in 0.02 m sodium phosphate buffer (pH 7) at maximally 56 mg nicotine h(-1) g dry cell(-1). Biomaterials, 2005 Jun, 26(16), 3277 - 84 The interaction of chitosan with fibroblast growth factor-2 and its protection from inactivation; Masuoka K et al.; Application of ultraviolet light (UV) irradiation to a photocrosslinkable chitosan (Az-CH-LA) aqueous solution including fibroblast growth factor-2 (FGF-2) results within 30s in an insoluble, flexible hydrogel . The retained FGF-2 molecules in the chitosan hydrogel remain biologically active, and are released from the chitosan hydrogel upon the in vivo biodegradation of the hydrogel . In view of these findings, we here tested the interaction of chitosan with FGF-2, thereby modifying and stabilizing the FGF-2 activity from inactivations . The photocrosslinkable chitosan hydrogel has a low affinity for FGF-2 (Kd=6.12x10(-7)m) . Soluble chitosan (CH-LA; Az-CH-LA without photocrosslinkable azide group) substantially prolonged the biological half-life time of FGF-2 . Furthermore, CH-LA could protect the FGF-2 activity from inactivation, such as heat, proteolysis, and acid . The effect of chitosan on the FGF-2 activity is of a protective nature, since it had no effect of modifying the FGF-2 activity directly on growth of human umbilical vein endothelial cells (data not shown) . Thus, one of the ways by which the chitosan potentiated the FGF-2 activity could be through protecting it from inactivations by the interaction between FGF-2 and chitosan molecules. Biomaterials, 2005 Jun, 26(16), 3165 - 72 Electrospun dual-porosity structure and biodegradation morphology of Montmorillonite reinforced PLLA nanocomposite scaffolds; Lee YH et al.; Combining a nanocomposite technique and the electrospinning process, a robust dual-porosity scaffold structure was developed for a facile transport of metabolic nutrients and wastes through the nano-sized pores and for the cell implantation and blood vessel invasion through the micro-sized pores . The montmorillonite (MMT) nano-sized platelets were incorporated into poly(L-lactic acid) (PLLA) solution, which was subsequently electrospun and mechanically entangled by a cold compression molding process for a robust 3-dimensional scaffold structure . Using a salt leaching/gas forming method, micro-sized pores were developed in the electrospun fiber bundles giving a dual-porosity scaffold structure . Compared with the pristine PLLA scaffold, the developed nanocomposite fibrous scaffold structure exhibited increased strength and improved structural integrity during the biodegradation process . The nanocomposite scaffold systems also exhibited many tiny pinholes desirably generated on the scaffold walls without serious fragmentation during biodegradation reactions. Mar Environ Res, 2005 Jun, 59(5), 419 - 34 Assessing degradation capability of aerobic indigenous microflora in PAH-contaminated brackish sediments; Abbondanzi F et al.; A study was conducted to determine polycyclic aromatic hydrocarbons (PAHs) distribution and microbial population changes in brackish sediments from an Italian lagoon included in the Ramsar List of Wetlands of International Importance . The presence and level of PAH-degrading bacteria were estimated by the most probable number (MPN) enumeration technique, whereas degradation capability towards target compounds was checked against loss of spiked PAHs (Phenanthrene, Anthracene and Fluoranthene) in MPN tubes after incubation in optimal conditions . Chemical analyses and microbiological counts suggested a potential for PAHs biodegradation by natural occurring populations of sediment microorganisms, thus indicating an "optimal range" in sediment PAHs concentrations, outside of which the natural selection of the indigenous microflora did not occur . The MPN procedure here described, provided an effective and reliable way to simultaneously determine microbial population densities and subsequent confirmation of the biodegradation capability of sediment indigenous microflora when exposed to laboratory and environmental concentrations of PAHs. FEMS Microbiol Lett, 2004 Dec 15, 241(2), 215 - 20 Non-exhaustive extraction techniques (NEETs) for the prediction of naphthalene mineralisation in soil; Patterson CJ et al.; Non-exhaustive extraction techniques (NEETs) have been shown to measure the putatively bioavailable fraction of hydrophobic compounds in soil . To date, these studies have only considered bioavailability in a single soil type . In this study, naphthalene was amended into five different soil types and mineralisation, bacterial biosensor response and the number of indigenous microbial naphthalene degraders were determined . Two NEETs were used to extract the naphthalene from soil; hydroxypropyl-beta-cyclodextrin (HPCD) and XAD-4 . The HPCD extractable fraction correlated closely (R(2)=0.917) with the portion that was mineralised, but the XAD-4 extract did not (R(2)=0.044) . HPCD may be ideal for the rapid assessment of the fraction of a hydrophobic organic contaminant that is available for biodegradation . A NEET that complements environmental microbial analysis will enhance our understanding of soil pollution interactions and equip us better in designing risk assessment models that integrate biological parameters . This application, although refined for soil samples, should be transferable to other environmental matrices. Eur Surg Res, 2004 Nov-Dec, 36(6), 376 - 85 Biodegradation of absorbable sutures in body fluids and pH buffers; Freudenberg S et al.; OBJECTIVE: This study measures the influence of body fluids on the loss of tensile strength of absorbable sutures in vitro . METHODS: Nine synthetic absorbable sutures were incubated in different gastrointestinal fluids, as well as in blood and three buffers . Stretch tests were performed after days 0, 7, 14, and 21 . RESULTS: Tensile strength varied from 18.5 to 32.8 N, and elasticity varied from 9.5 to 51% of the initial length . The influence of pH, blood, and gastric juice was negligible on all sutures except PDS II . Except for Monocryl, all sutures, especially Polysorb and Vicryl, lost tensile strength much faster in bile, jejunal and pancreatic juices than in the corresponding buffers . CONCLUSION: The biodegradation of sutures varies greatly in different body fluids independent of differences in pH . 2004 S . Karger AG, Basel. Environ Pollut, 2005 Mar, 134(2), 315 - 22 PAH dissipation in a contaminated river sediment under oxic and anoxic conditions; Quantin C et al.; A batch experiment was conducted to compare PAH degradation in a polluted river sediment under aerobic and anaerobic conditions, and to investigate whether input of fresh organic material (cellulose) could enhance such degradation . All measurements were checked against abiotic control treatments to exclude artifacts of sample preparation and non-biological processes like aging . Three- and four-ring PAHs could be degraded by the indigenous microbial community under aerobic conditions, but anaerobic metabolism based on iron and sulphate reduction was not coupled with PAH degradation of even the simplest 3-ring compounds like phenanthrene . Cellulose addition stimulated both aerobic and anaerobic respiration, but had no effect on PAH dissipation . We conclude that natural attenuation of PAHs in polluted river sediments under anaerobic conditions is exceedingly slow . Dredging and biodegradation on land under aerobic conditions would be required to safely remediate and restore polluted sites. J Control Release, 2005 Jan 3, 101(1-3), 137 - 49 The role of branched polyesters and their modifications in the development of modern drug delivery vehicles; Dailey LA et al.; Branched polyesters consisting of poly (vinyl alcohol) (PVA) grafted with chains of poly (lactic-co-glycolic acid) (PLGA) represent a new class of biodegradable polymers showing significant potential for the development of a variety of drug delivery vehicles . The amphiphilic character and the resulting increase in hydrophilicity of this class of polymers provide advantages when packaging sensitive drug molecules, such as proteins, peptides or DNA . Furthermore, the PVA backbone can be modified, for example, with sulfobutyl moieties or amine structures, to create polymers with negative or positive charges . The ability to modify not only the backbone but also the length of the PLGA side chains results in an extremely flexible polymer system, which can be adapted to meet the needs of almost any drug substance . Further, the rate of biodegradation may also be manipulated through polymer modification to achieve half-lives ranging from several hours to several weeks . This review provides an overview of the three major groups of branched polyesters based upon poly (vinyl alcohol)-grafted poly (lactic-co-glycolic acid) (PVA-g-PLGA), namely, the neutrally charged PVA-g-PLGA, the negatively charged sulfobutyl-modified PVA-g-PLGA and the positively charged amine-modified PVA-g-PLGA, as well as their use in various drug delivery systems. J Contam Hydrol, 2005 Jan, 76(1-2), 1 - 18 Assessing in situ mineralization of recalcitrant organic compounds in vadose zone sediments using delta13C and 14C measurements; Kirtland BC et al.; Few techniques exist to measure the biodegradation of recalcitrant organic compounds such as chlorinated hydrocarbons (CHC) in situ, yet predictions of biodegradation rates are needed for assessing monitored natural attenuation . Traditional techniques measuring O2, CO2, or chemical concentrations (in situ respiration, metabolite and soil air monitoring) may not be sufficiently sensitive to estimate biodegradation rates for these compounds . This study combined isotopic measurements (14C and delta13C of CO2 and delta13C of CHCs) in conjunction with traditional methods to assess in situ biodegradation of perchloroethylene (PCE) and its metabolites in PCE-contaminated vadose zone sediments . CHC, ethene, ethane, methane, O2, and CO2 concentrations were measured over 56 days using gas chromatography (GC) . delta13C of PCE, trichloroethylene (TCE) and cis-1,2-dichloroethylene (DCE), delta13C and 14C of vadose zone CO2 and sediment organic matter, and delta13C, 14C, and deltaD of methane were measured using a GC-isotope ratio mass spectrometer or accelerator mass spectrometer . PCE metabolites accounted for 0.2% to 18% of CHC concentration suggesting limited reductive dechlorination . Metabolites TCE and DCE were significantly enriched in (13)C with respect to PCE indicating metabolite biodegradation . Average delta13C-CO2 in source area wells (-23.5 per thousand) was significantly lower compared to background wells (-18.4 per thousand) indicating CHC mineralization . Calculated CHC mineralization rates were 0.003 to 0.01 mg DCE/kg soil/day based on lower 14C values of CO2 in the contaminated wells (63% to 107% modern carbon (pMC)) relative to the control well (117 pMC) . Approximately 74% of the methane was calculated to be derived from in situ CHC biodegradation based on the 14C measurement of methane (29 pMC) . 14C-CO2 analyses was a sensitive measurement for quantifying in situ recalcitrant organic compound mineralization in vadose zone sediments for which limited methodological tools exist. Biomaterials, 2005 May, 26(15), 2767 - 2773 Nacre/bone interface changes in durable nacre endosseous implants in sheep; Berland S et al.; Raw nacre implants persist even after 9 months of implantation into bone tissue in sheep . However the nacre surface undergoes a limited biodegradation process . Smooth-surfaced nacre implants were seen to become microporous after implantation . The results of these long-term, in vivo studies show that the overall process involves bone-resorbing cells, relies on a two-phase mechanism and may correspond to a regulation process . The rate of surface change depends on the bone implantation site and the nacre/bone interaction . The in vivo biodegradability of nacre is a highly variable parameter . The size and shape of the implanted nacre and the cellular environment of the implant are key factors in determining the biodegradation kinetics of the nacre in a living system. Biomaterials, 2005 May, 26(15), 2467 - 77 Biosynthetic hydrogel scaffolds made from fibrinogen and polyethylene glycol for 3D cell cultures; Almany L et al.; Tissue engineering scaffolds are fabricated from either biological materials, which provide biofunctional signals and interact well with cells, or from synthetic polymers, which provide precise control over their structural properties . We describe a biosynthetic hybrid scaffold comprised of a fibrinogen backbone and crosslinked with difunctional polyethylene glycol (PEG) side chains . Denatured fibrinogen fragments are PEGylated with PEG-diacrylates, mixed with photoinitiator and exposed to UV light to form a hydrogel material in the presence of a cell suspension . This unique hydrogel material provides a distinct advantage over other scaffold materials because its mechanical properties are highly malleable while the biological functionality is maintained by the backbone of the polymeric network . The elastic modulus of the PEG-fibrinogen hydrogel is dependent on the molecular weight of the PEG constituent and proportional to the percent polymeric composition . The biological domains in the fibrinogen backbone provide attachment motifs for endothelial cell and smooth muscle cell adhesion as well as proteolytic sensitivity for biodegradation . Smooth muscle cells demonstrate the ability to proteolytically penetrate through the hydrogel material and form interconnecting networks of cells . Our efforts to develop novel biodegradable scaffolds for cultivating cells in a 3D environment are beneficial for tissue regeneration therapies. Pharm Dev Technol, 2004 Nov, 9(4), 399 - 407 Biodegradation behavior of gellan gum in simulated colonic media; Singh BN et al.; The objective of this investigation was to test the biodegradability of gellan gum in the presence of galactomannanase in order to explore its suitability for the development of colon-specific controlled delivery systems . Gellan beads containing azathioprine (AZA) were prepared by ionotropic gelation in the presence of Ca2+ ions and were coated with an enteric polymer, Eudragit S-100 . The effects of the simulated colonic fluid (SCF, pH 7.4 phosphate buffer) containing 15 mg/mL of galactomannanase on the in vitro release profiles of uncoated and enteric-coated beads were investigated, and the morphological changes in the structure of uncoated beads were assessed by scanning electron microscopy (SEM) . In addition, 1% solution of deacetylated gellan gum was prepared and several aliquots of the resulting solution were evaluated rheologically to determine the concentration- and time-dependent effects of galactomannanase . Based on the percent drug released at 2 h, approximately 10% greater amount of drug was released in the SCF containing galactomannanase when compared with the enzyme-free dissolution medium . Results of rheological studies demonstrated that effects of galactomannanase on the viscosity of gellan gum solution are concentration-dependent rather than time-dependent . A significant decrease in the viscosity was noted in the presence of galactomannanase at a concentration of 15 mg/ mL, indicating that the polysaccharide degraded in an enzymatic reaction . SEM micrographs showed a distinct disruption of the polymeric network in the SCF . Overall, the results suggest that gellan gum undergoes significant degradation in the presence of galactomannanase which in turn facilitates the drug release from beads in the SCF in a controlled manner, thus approving the suitability of gellan gum as a carrier for controlled colonic delivery. Biomaterials, 2005 May, 26(14), 1961 - 8 Study of gelatin-containing artificial skin V: fabrication of gelatin scaffolds using a salt-leaching method; Lee SB et al.; Porous gelatin scaffolds were prepared using a salt-leaching method and these were compared to scaffolds fabricated using a freeze-drying method . The salt-leached gelatin scaffolds were easily formed into desired shapes with a uniformly distributed and interconnected pore structure with an average pore size of around 350mum . The mechanical strength and the biodegradation rate of the scaffolds increased with the porosity, and were easily modulated by the addition of salt . After 1 week of in vitro culturing, the fibroblasts in salt-leached scaffolds were mainly attached on the surface of the pores in the scaffold, whereas cells seeded on freeze-dried scaffolds were widely distributed and aggregated on the top and the bottom of the scaffold . After 14d of culturing, the fibroblasts showed a good affinity to, and proliferation on, the gelatin scaffolds without showing any signs of biodegradation . An in vivo study of cultured artificial dermal substitutes showed that an artificial dermis containing the fibroblasts enhanced the re-epithelialization of a full-thickness skin defect when compared to an acellular scaffold after 1 week. Environ Sci Technol, 2004 Nov 15, 38(22), 5888 - 94 Photosensitized degradation of bisphenol A by dissolved organic matter; Chin YP et al.; The direct and indirect photolysis of bisphenol A (BPA) was investigated using a solar simulator in the absence and presence of dissolved organic matter (DOM) . BPA degradation by direct photolysis was significantly slower than its rate in the presence of DOM . In natural waters, the direct photolytic pathway would be even less important due to light screening effects . Surprisingly, differences in the rate of indirect BPA photolysis were relatively small between DOM samples . Two of the DOM samples represented terrestrial (Suwannee River fulvic acid) and autochthonous (Lake Fryxell) geochemical endmembers . The third DOM (Fulton County, Ohio) was derived from a temperate artificial wetland . We were unable to correlate BPA photoreactivity to the structural components of DOM or its extinction coefficient at 280 nm . The addition of methanol, a hydroxyl radical scavenger, to reaction solutions slowed but did not completely quench the indirect photolysis of BPA . This observation suggests that BPA photodegrades via multiple pathways involving other transients formed by the photolysis of DOM . Competitive experiments using 2,4,6-trimethylphenol also reduce the reaction rate of BPA by DOM and implythat other DOM-derived phototransients (e.g., excited triplet state DOM) are involved in the reaction . The reaction rate coefficients reported under solar-simulated irradiance in the presence of DOM are significantly faster than those reported for the microbial degradation of BPA . Thus, in natural surface waters photosensitized transformation of BPA by dissolved organic matter may be as important as biodegradation. Biodegradation, 2004 Dec, 15(6), 475 - 85 Biodegradation of PCE and TCE in landfill leachate predicted from concentrations of molecular hydrogen: a case study; Gonsoulin ME et al.; The Refuse Hideaway Landfill (23-acre) received municipal, commercial, and industrial waste between 1974 and 1988 . It was designed as a "natural attenuation" landfill and no provision was made to collect and treat contaminated water . Natural biological degradation through sequential reductive dechlorination had been an important mechanism for natural attenuation at the site . We used the concentration of hydrogen to forecast whether reductive dechlorination would continue over time at particular locations in the plume . Based on published literature, reductive dechlorination and natural attenuation of PCE, TCE, and cis-DCE can be expected in the aquifer if the concentration of molecular hydrogen in monitoring wells are adequate (> 1 nanomolar) . Reductive dechlorination can be expected to continue as the ground water moves down gradient . Natural attenuation through reductive dechlorination is not expected in flow paths that originate at down gradient monitoring wells with low concentrations of molecular hydrogen (< 1 nanomolar) . In three monitoring wells at the margin of the landfill and in five monitoring wells down gradient of the landfill, ground water maintained a molecular hydrogen concentration, ranging from 1.30 to 9.17 nanomolar, that is adequate for reductive dechlorination . In three of the monitoring wells far down gradient of the landfill, the concentration of molecular hydrogen (0.33 to 0.83 nanomolar) was not adequate to support reductive dechlorination . In wells with adequate concentrations of hydrogen, the concentrations of chlorinated volatile organic compounds were attenuated over time, or concentrations of chlorinated volatile organics were below the detection limit . In wells with inadequate concentrations of hydrogen, the concentrations of chlorinated organic compounds attenuated at a slower rate over time . In wells with adequate hydrogen the first order rate of attenuation of PCE, TCE, cis-DCE and total chlorinated volatile organic compounds varies from 0.38 to 0.18 per year . In wells without adequate hydrogen the rate varies from 0.015 to 0.006 per year. Biodegradation, 2004 Dec, 15(6), 387 - 94 Long-term sustainability of reductive dechlorination reactions at chlorinated solvents sites; Newell CJ et al.; The sustainability of biodegradation reactions is of interest at Type 1 chlorinated solvent sites where monitored natural attenuation is being considered as a remedial alternative . Type 1 chlorinated solvent sites are sites undergoing reductive dechlorination where anthropogenic substrates (such as landfill leachate or fermentable organics in the waste materials) ferment to produce hydrogen, a key electron donor . A framework is provided that classifies Type 1 chlorinated solvent sites based on the relative amounts and the depletion rates of the electron donors and the electron acceptors (i.e., chlorinated solvents) . Expressions are presented for estimating the total electron donor demand due to the presence of solvents and competing electron acceptors such as dissolved oxygen, nitrate, and sulfate . Finally, a database of 13 chlorinated solvent sites was analyzed to estimate the median and maximum mass discharge rate for dissolved oxygen, nitrate, and sulfate flowing into chlorinated solvent plumes . These values were then used to calculate the amount of hydrogen equivalents and potential for lost perchloroethylene (PCE) biodegradation represented by the inflow of these competing electron acceptors . The median and maximum mass of PCE biodegradation lost due to competing electron acceptors, assuming 100% efficiency, was 226 and 4621 kg year(-1), respectively. Biodegradation, 2004 Dec, 15(6), 359 - 69 Challenges in monitoring the natural attenuation of spatially variable plumes; Wilson RD et al.; Monitored natural attenuation may be applied as a risk-based remediation strategy if it can be established that contaminants are or will be reduced to some acceptable level at or before a compliance point . Contaminant attenuation is often attributed to intrinsic biodegradation, which in some circumstances may occur only at the plume fringes where electron acceptors from the surrounding uncontaminated zones mix by dispersion and diffusion with the plume . However, due to the common spatial and temporal variability exhibited by many plumes, the centreline monitoring approaches advocated in many natural attenuation protocols may be unable to detect natural attenuation occurring primarily by fringe processes . Snapshot data from a multilevel sampling well transect across an MTBE plume at Vandenberg Air Force Base, CA, USA, illustrate the difficulty of centreline monitoring and the challenge of providing sufficient detail to detect attenuation processes that may be occurring primarily at plume fringes . In a study of a phenols plume in Wolverhampton, UK, high-resolution multilevel wells demonstrated that the key biodegradation processes were restricted spatially to the upper fringe of the plume and were rate-limited by transverse dispersion and diffusion of electron acceptors into the plume . Thus the overall extent of biodegradation was considerably less than suggested by a plume-scale analysis of total electron acceptor and contaminant budgets . These examples indicate that more robust and cost-effective MNA assessments can be obtained using monitoring strategies that focus on the location of key biodegradation processes. Biodegradation, 2004 Dec, 15(6), 349 - 57 Definition, objectives, and evaluation of natural attenuation; Rittmann BE; Natural attenuation offers large benefits to owners and managers of contaminated sites, but often raises strong objections from those who live and work near a site and are asked to assume most of the long-term risks . Part of the controversy comes about because published definitions of natural attenuation do not identify a realistic end-point objective, and they also are ambiguous about the naturally occurring processes that can achieve the objective . According to guidance from the U.S . National Research Council (NRC 2000), destruction and strong immobilization are the naturally occurring processes that achieve a realistic objective: containing the contaminant relatively nears its source, thereby minimizing exposure risks . The strategy for obtaining solid evidence that the objective is being achieved requires measurements that establish a cause-and-effect relationship between contaminant loss and a destruction or strong-immobilization reaction . The cause-and-effect relationship is best documented with reaction footprints, which typically are concentration changes in reactants or products of the destruction or immobilization reaction . MTBE presents a contemporary example in which footprint evidence for biodegradation is especially crucial, since aerobic biodegradation of MTBE requires special conditions not present at all sites: a high availability of dissolved oxygen and bacteria expressing particular oxygenase enzymes. J Biomater Sci Polym Ed, 2004, 15(10), 1281 - 304 Differential degradation rates in vivo and in vitro of biocompatible poly(lactic acid) and poly(glycolic acid) homo- and co-polymers for a polymeric drug-delivery microchip; Grayson AC et al.; The biocompatibility and biodegradation rate of component materials are critical when designing a drug-delivery device . The degradation products and rate of degradation may play important roles in determining the local cellular response to the implanted material . In this study, we investigated the biocompatibility and relative biodegradation rates of PLA, PGA and two poly(lactic-co-glycolic acid) (PLGA) polymers of 50:50 mol ratio, thin-film component materials of a drug-delivery microchip developed in our laboratory . The in vivo biocompatibility and both in vivo and in vitro degradation of these materials were characterized using several techniques . Total leukocyte concentration measurements showed normal acute and chronic inflammatory responses to the PGA and low-molecular-weight PLGA that resolved by 21 days, while the normal inflammatory responses to the PLA and high-molecular-weight PLGA were resolved but at slower rates up to 21 days . These results were paralleled by thickness measurements of fibrous capsules surrounding the implants, which showed greater maturation of the capsules for the more rapidly degrading materials after 21 days, but less mature capsules of sustained thicknesses for the PLA and high-molecular-weight PLGA up to 49 days . Gel-permeation chromatography of residual polymer samples confirmed classification of the materials as rapidly or slowly degrading . These materials showed thinner fibrous capsules than have been reported for other materials by our laboratory and have suitable biocompatibility and biodegradation rates for an implantable drug-delivery device. Water Res, 2004 Dec, 38(20), 4323 - 30 Development of enzyme-linked immunosorbent assay for detection of alkylphenol polyethoxylates and their biodegradation products; Goda Y et al.; An enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative analysis of alkylphenol polyethoxylates (APnEOs) and their biodegradation products . To generate a specific monoclonal antibody (mAb) for the ELISA, hybridoma cells were produced by the fusion of mouse myeloma cells and spleen cells from mice immunized with nonylphenol polyethoxylate (NPnEO) derivatives coupled to bovine serum albumin . The developed ELISA showed the detection limits of 16 and 30 microg/L NP10EO when 10% and 60% (v/v) methanol solutions were used as assay diluent . The mAb was shown to be specific to APnEOs and their metabolites, such as short-ethoxy-chain APnEOs and alkylphenoxy carboxylic acids, except for nonylphenol . Moreover, no response was observed with non-APnEO surfactants as well as other compounds structurally similar to APnEOs . The percentage river water recoveries of 85-118% were obtained for 10 microg/L NP10EO fortification after preconcentration by C18 solid-phase extraction . The ELISA was also validated by comparing it with high-performance liquid chromatography for the analysis of APnEOs and their metabolites in river samples; the correlation coefficient between the values obtained by these assays was 0.96. Ann Ig, 2004 Jan-Apr, 16(1-2), 307 - 20 {Alkylphenols in the environment: a risk for human health?}; Ensabella F et al.; Endocrine Disrupting Chemicals (ECD) are a class of chemical compounds widely utilized for many industrial and civil applications and, consequently, widely diffused in the environment . Due to their chemical-physical characteristics, ECD may interfere with several endocrine functions in humans . Alkylphenols (APs), mainly produced by biodegradation of alkylphenols polyethoxylates surfactants, are a relevant group of ECD, both for their environmental diffusion and demonstrated estrogenic activity . Aim of this paper is to assess the potential risk of exposure to APs for humans, on the basis of the available data in literature concerning APs: environmental levels, accumulation in sediments and biota, toxicological effects on experimental animals. Int J Phytoremediation, 2004, 6(3), 227 - 38 Bacterial community evaluation during establishment of tall fescue (Festuca arundinacea) in soil contaminated with pyrene; Chen YC et al.; A greenhouse study was conducted to monitor microbial community dynamics related to contaminant concentration and plant growth during the phytoremediation of pyrene . Soil microbial communities in both bulk and rhizosphere soils were assessed using a polymerase chain reaction--denaturing gradient gel electrophoresis (PCR-DGGE) . However, no correlation between pyrene concentration and bacterial community shifts was observed . Even though plants significantly enhanced pyrene degradation (undetectable after 91 d for planted treatments compared with 82 mg/kg for unplanted treatments after 147 d with initial concentration of 758 mg/kg), biodegradation may have been accomplished by the pre-existing microbial community . It is also possible that the method was unable to pick up subtle community shifts, considering that the carbon source from pyrene was only 3.7% of the existing soil organic matter . This research suggests that plants significantly enhance degradation and mineralization of pyrene in soil, although there was no conclusive evidence supporting any specific bacterial activity responsible for this enhancement. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi, 2004 Oct, 21(5), 717 - 20 {Study on relationship of biodegradable properties of PGLA film in vivo and in vitro}; Sun J et al.; This experimental study on the biodegradable properties of poly(glycolide-co-lactide){PGLA} film in vivo and in vitro was aimed to investigate the relationship between in vivo degradation process and in vitro degradation process . First, PGLA film was cut to 1 cm x 1 cm in size . It was put into artificial saliva and PBS solution respectively in vitro, and was implanted into subcutaneous tissue in Wistar rat in vivo . Then the mass loss rate was calculated every week not only for sample in vitro but also in vivo . The molecular weight was measured every two weeks . The results showed that the degradable speed of PGLA was faster in artificial saliva than in PBS solution . The change of molecular weight was earlier than that of mass loss rate . The degradable period in vitro was about 9-10 weeks . The degradable period in vivo was about 8 weeks . The rate of in vivo degradation was 1.33 times faster than that of in vitro . In conclusion, the degradation of PGLA in vitro was mainly a chemical degradation process achieved by hydrolysis of ester bond . The degradation of PGLA in vivo would be affected by stress and by biological factors, thus the degradation process was apparently faster in vivo, but both accorded with the degradation kinetics model of aliphatic polyester . There was some relationship of biodegradation between in vitro and in vivo. Environ Technol, 2004 Oct, 25(10), 1189 - 99 Performance of a UASB-digester system treating domestic wastewater; Alvarez JA et al.; The anaerobic treatment of raw domestic wastewater by a novel technology consisting of an Up-flow Anaerobic Sludge Bed (UASB) reactor combined with a completely mixed digester for the stabilisation of the UASB sludge was assessed . A pilot-scale plant of the so-called UASB-Digester system was located at the municipal wastewater treatment facility of Santiago de Compostela (Northwest of Spain) . The main aim of the Digester was to enhance the biodegradation of influent solids retained in the UASB reactor at low temperatures, then increasing its specific methanogenic activity . The sludge drawn from the middle zone of the UASB entered the upper zone of the Digester and then circulated from the bottom of the Digester to the UASB bottom . Circulating in an automated semi-continuous way, the flow of this sludge stream was selected in order to set a previously defined hydraulic retention time (HRT) (16-27 d) in the digester . The Digester temperature was set at an optimum value ranging from 25 to 35 degrees C . The steady state efficiency of the UASB system, at 6-8 h of HRT, 15-16 degrees C of temperature and 330-360 mg l(-1) of influent total chemical oxygen demand (TCOD) was 79% of total suspended solids (TSS) removal, 52% of TCOD removal and 60% of biological oxygen demand (BOD5) removal . The hydrolysis of retained solids reached 85%, while excess sludge generation was only 7% of influent TCOD . A stable anaerobic (pre)treatment of diluted domestic wastewater was reached as the sludge concentration in the reactor remained mainly constant and the specific methanogenic activity showed a slight increase. Appl Microbiol Biotechnol . 2004 Nov 12; {Epub ahead of print} Influence of the carbon/nitrogen/phosphorus ratio on polycyclic aromatic hydrocarbon degradation by Mycobacterium and Sphingomonas in soil; Leys NM et al.; Biodegradation of polycyclic aromatic hydrocarbons (PAHs) in the environment is often limited due to unfavorable nutrient conditions for the bacteria that use these PAHs as sole source of carbon and energy . Mycobacterium and Sphingomonas are 2 PAH-degrading specialists commonly present in PAH-polluted soil, but not much is known about their specific nutrient requirements . By adding different inorganic supplements of nitrogen (N) and phosphorus (P), affecting the overall carbon/nitrogen/phosphorus ratio of soil in soil slurry degradation tests, we investigated the impact of soil inorganic N and P nutrient conditions on PAH degradation by PAH-degrading Sphingomonas and Mycobacterium strains . The general theoretically calculated C/N/P ratio of 100/10/1 (expressed in moles) allowed rapid PAH metabolization by Sphingomonas and Mycobacterium strains without limitation . In addition, PAH-degradation rate and extent was not affected when ca . ten times lower concentrations of N and P were provided, indicating that Sphingomonas and Mycobacterium strains are capable of metabolizing PAHs under low nutrient conditions . Nor does PAH-degradation seem to be affected by excesses of N and P creating an imbalanced C/N/P ratio . However, supplements of N and P salts increased the salinity of soil slurry solutions and seriously limited or even completely blocked biodegradation. Int J Syst Evol Microbiol, 2004 Nov, 54(Pt 6), 2067 - 72 Arthrobacter psychrophenolicus sp . nov., isolated from an alpine ice cave; Margesin R et al.; On the basis of phenotypic, genotypic and chemotaxonomic characteristics, a novel species belonging to the genus Arthrobacter is described . A facultatively psychrophilic bacterium, strain AG31(T), was isolated from an alpine ice cave . The aerobic, Gram-positive, non-spore-forming, non-motile strain exhibited a rod-coccus growth cycle and produced a yellow pigment . Good growth and phenol biodegradation occurred at a temperature range of 1-25 degrees C . Up to 10 mM phenol was utilized as a sole carbon source . Glucose was not assimilated . Analysis of the 16S rRNA gene revealed that strain AG31(T) represents a distinct lineage within the genus Arthrobacter, being most closely related to Arthrobacter sulfureus . The level of DNA-DNA relatedness to the type strain of A . sulfureus was 29.9 % . Anteiso-C(15 : 0) was the predominant fatty acid (72 %) . Strain AG31(T) exhibited A4alpha l-lys-l-Glu-type peptidoglycan and contained glucose as the only cell-wall sugar . MK-10 was the predominant menaquinone, and the polar lipid pattern consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and an unidentified glycolipid . Strain AG31(T) (=DSM 15454(T)=LMG 21914(T)) is assigned as the type strain of a novel Arthrobacter species, Arthrobacter psychrophenolicus sp . nov. Biomacromolecules, 2004 Nov-Dec, 5(6), 2258 - 68 Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s bearing functionalizable carbonate building blocks: II . Enzymatic biodegradation and in vitro biocompatibility assay; Yang J et al.; In a previous study, we have reported chemical synthesis of novel aliphatic poly(butylene succinate-co-cyclic carbonate) P(BS-co-CC)s bearing various functionalizable carbonate building blocks, and this work will continue to present our new studies on their enzymatic degradation and in vitro cell biocompatibility assay . First, enzymatic degradation of the novel P(BS-co-CC) film samples was investigated with two enzymes of lipase B Candida Antartic (Novozyme 435) and lipase Porcine Pancreas PPL, and it was revealed that copolymerizing linear poly(butylene succinate) PBS with a functionalizable carbonate building block could remarkably accelerate the enzymatic degradation of a synthesized product P(BS-co-CC), and its biodegradation behavior was found to strongly depend on the overall impacts of several important factors as the cyclic carbonate (CC) comonomer structure and molar content, molar mass, thermal characteristics, morphology, the enzyme-substrate specificity, and so forth . Further, the biodegraded residual film samples and water-soluble enzymatic degradation products were allowed to be analyzed by means of proton nuclear magnetic resonance (1H NMR), gel permeation chromatograph (GPC), differential scanning calorimeter (DSC), attenuated total reflection FTIR (ATR-FTIR), scanning electron microscope (SEM), and liquid chromatograph-mass spectrometry (LC-MS) . On the experimental evidences, an exo-type mechanism of enzymatic chain hydrolysis preferentially occurring in the noncrystalline domains was suggested for the synthesized new P(BS-co-CC) film samples . With regard to their cell biocompatibilities, an assay with NIH 3T3 mouse fibroblast cell was conducted using the novel synthesized P(BS-co-CC) films as substrates with respect to the cell adhesion and proliferation, and these new biodegradable P(BS-co-CC) samples were found to exhibit as low cell toxicity as the PLLA control, particularly the two samples of poly(butylene succinate-co-18.7 mol % dimethyl trimethylene carbonate) P(BS-co-18.7 mol % DMTMC) and poly(butylene succinate-co-21.9 mol % 5-benzyloxy trimethylene carbonate) P(BS-co-21.9 mol % BTMC) were interestingly found to show much better cell biocompatibilities than the PLLA reference. Biodegradation, 2004 Oct, 15(5), 303 - 13 Biodegradation of dibenzo-p-dioxin, dibenzofuran, and chlorodibenzo-p-dioxins by Pseudomonas veronii PH-03; Hong HB et al.; The dioxin-degrading strain Pseudomonas veronii PH-03 was isolated from contaminated soil by selective enrichment techniques . Strain PH-03 grew on dibenzo-p-dioxin and dibenzofuran as a sole carbon source . Further, 1-chlorodibenzo-p-dioxin, 2-chlorodibenzo-p-dioxin and other dioxin metabolites, salicylic acid, and catechol were also metabolized well . Resting cells of strain PH-03 transformed dibenzo-p-dioxin, dibenzofuran, 2,2',3-trihydroxybiphenyl, and some chlorodioxins to their corresponding metabolic intermediates such as catechol, salicylic acid, 2-hydroxy-(2-hydroxyphenoxy)-6-oxo-2,4-hexadienoic acid, and chlorocatechols . The formation of these metabolites was confirmed by comparison of gas chromatography-mass spectrometry (GC-MS) data with those of authentic compounds . Although we did observe the production of 3,4,5,6-tetrachlorocatechol (3,4,5,6-TECC) from 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD) with resting cell suspensions of PH-03, growth of strain PH-03 in the presence of 1,2,3,4-TCDD was poor . This result suggests that strain PH-03 is unable to utilize 3,4,5,6-TECC, even at very low concentration (0.01 mM) due to its toxicity . In cell-free extracts of DF-grown cells, 2,2',3-trihydroxybiphenyl dioxygenase, 2-hydroxy-6-oxo-6-phenyl-2,4-hexadienoic acid hydrolase, and catechol-2,3-dioxygense activities were detected . Moreover, the activities of meta-pyrocatechase and 2,2',3-trihydroxybiphenyl dioxygenase from the crude cell-free extracts were inhibited by 3-chlorocatechol . However, no inhibition was observed in intact cells when 3-chlorocatechol was formed as intermediate. Chemosphere, 2005 Jan, 58(1), 33 - 40 Solubilization and biodegradation of phenanthrene in mixed anionic-nonionic surfactant solutions; Zhao B et al.; The effects of mixed anionic-nonionic surfactants, sodium dodecyl sulfate (SDS) mixed with Tween80 (TW80), Triton X-100 (TX100) and Brij35 respectively on the solubility enhancement and biodegradation of phenanthrene in the aqueous phase were investigated . The efficiency of solubilization and biodegradation of phenanthrene in single-, and mixed-surfactant solutions were also compared . The critical micellar concentrations (CMCs) of mixed surfactants were sharply lower than that of sole SDS . The degree of solubility enhancements by the mixed surfactants followed the order of SDS-TW80>SDS-Brij35>SDS-TX100 . Synergistic solubilization was observed in the mixed surfactant solutions, in which the molar ratios of SDS to nonionic surfactant were 1:0, 9:1, 7:3, 5:5, 3:7, 1:9 and 0:1 while the total concentration of surfactants was kept at 5.0 and 10.0 mM, respectively . SDS-Brij35 exhibited more significant degree of synergistic solubility enhancement for phenanthrene . The mixed surfactants exhibited no inhibitory effect on biodegradation of phenanthrene . Substantial amounts of the solubilized phenanthrene by mixed surfactants were completely degraded by phenanthrene-degrading microorganisms within 96 h . The results suggested that anionic-nonionic surfactants would improve the performance of remediation of PAH-contaminated soils. Environ Manage, 2004 Sep, 34(3), 441 - 8 Epub 2004 Aug 24. Long-term monitoring and prediction for settlement and composition of refuse in Shanghai Laogang Municipal Landfill; Jiangying L et al.; Parameters about composition of refuse such as mass percentage of biodegradable matter, volatile solid, organic carbon, cellulose, total sugar, and settlement were monitored and analyzed in a large-scale experimental unit . The empirical formulas between composition and refuse age were established in terms of the data obtained from the experimental unit and verified by comparing with the corresponding parameters of refuse in the closed landfill units from 1991 until 1994 in the Shanghai Laogang Municipal Landfill . Furthermore, the long-term prediction for the composition of refuse was made, and it was predicted that the half-life is 7 to 11 years for biodegradable matter, 9 to 12 years for organic carbon or volatile solid, 7 to 16 years for cellulose, and 4 to 6 years for total sugar . In addition, a mathematical model, based on the mechanism of refuse biodegradation in the landfill, was developed to simulate the relationship between the settlement and the refuse age and manifests the secondary settlement potential . The mathematical model was proved not only to be reliable but also should be accurate for predicting the settlement of the landfill . The secondary settlement, which mainly results from the slow and gradual biodegradation of refuse, is linear with respect to the exponent of refuse age . Finally, according to the settlement model and empirical biodegradation formulas, it may be predicted that, 79.4% of biodegradable matter, 92.9% of total sugar, 72.7% of volatile solid and organic carbon, and 73.1% of cellulose will be biodegraded and that 79% of the maximum secondary settlement potential will occur before the Shanghai Laogang Municipal Landfill is in a high stabilization situation, i.e., approximately 21 years after final closure. Huan Jing Ke Xue, 2004 Jul, 25(4), 82 - 5 {Anaerobic biodegradation of nitrophenols with glucose as co-substrate}; She ZL et al.; A batch anaerobic test was conducted to examine the biodegradation of 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol and 2,6-dinitrophenol through measuring accumulative methane production . The Relative activity values were used to judge the inhibition level of nitrophenols on methanogenic bacteria . The test conditions was as follow: glucose was used as co-substrate and the temperature is 35 degrees C . It didn't cause inhibition when concentrations of 2-nitrophenol, 4-nitrophenol, 2,6-dinitrophenol and 2,4-dinitrophenol were below 24mg/L, 20mg/L, 12mg/L and 4mg/L respectively . Slight inhibition was caused when concentrations of 4-nitrophenol and 2,6-dinitrophenol were 24mg/L and 16mg/L-24mg/L respectively . Middle inhibition when concentrations of 2,4-dinitrophenol were 8mg/L-24mg/L was observed . The inhibition level was 2,4-dinitrophenol > 2,6-dinitrophenol > 4-nitrophenol > 2-nitrophenol. Environ Sci Pollut Res Int, 2004, 11(5), 291 - 6 Ecotoxicological characterisation and classification of existing chemicals . Examples from the ICCA HPV initiative and comparison with other existing chemicals; Licht O et al.; GOAL, SCOPE AND BACKGROUND: In 1998, the International Council of Chemical Associations (ICCA) launched a global initiative to investigate more than 1,000 HPV chemicals (High Production Volume, > or = 1,000 t/a) within the refocused OECD HPV Chemicals Programme . Up to the OECD SIDS Initial Assessment Meeting in April 2004 (SIAM 18) 147 ICCA dossiers (ca . 230 CAS-No) have been assessed based on a harmonised data set . The environmental profile and an ecotoxicological characterisation of these chemicals are presented here . Data for acute aquatic toxicity were correlated among each other, as well as data for fish (LC50, LD50) and rodents (LD50) . The data for acute aquatic toxicity are compared with other existing chemicals . METHODS: Data of the ICCA HPV chemicals from the OECD SIAM 11-18 are presented for: log Kow (as an indicator for bioaccumulation potential), biodegradation, acute aquatic toxicity and availability of long-term toxicity data . Correlation analysis was performed with log transformed data and a linear regression model was fitted to the data, if a significant correlation was found . Acute toxicity for fish and acute oral toxicity for rodents were correlated on a molar basis . Acute aquatic toxicity of the chemicals is compared with data from BUA reports 1-234 and a random EINECS sample (Knacker et al . 1995) . RESULTS AND DISCUSSION: According to the dossier information, 71 of the 147 ICCA chemicals are not 'readily biodegradable', 21 have a log Kow > or = 3, and 44 are 'toxic' (LC/EC50 < or = 10 mg/L) or 'very toxic' (LC/EC50 < or = 1 mg/L) to aquatic organisms . For 77, only the base set (acute fish, Daphnia and algae) is available, for the rest at least one long-term test (fish or Daphnia) is available and three tests for a mere 14 others . Based on the data presented, the SIAM gives recommendations for Environment and Human Health . 22 chemicals have been identified as a 'candidate for further work' for Environment and 16 for Human Health . The highest correlation coefficient was obtained correlating fish and Daphnia (r2 = 0.79) . LC50 (fish) is significantly correlated with LD50 (rodent), but data are widely scattered . The correlation is not improved after transforming LC50 (fish) to LD50 (fish), using BCF QSAR . Based on acute aquatic toxicity, 25.1% of the chemicals from the BUA reports 1-234 are classified as 'very toxic' (LC/EC50 < or = 1 mg/L) . This proportion is 2.5-fold higher than the ICCA HPV chemicals and 1.4-fold higher than the random EINECS sample . CONCLUSIONS: Correlation coefficients for aquatic toxicity data are rather uniform (0.57-0.79) compared with literature data, but also the best correlation was observed between fish and Daphnia . Because the scatter around the regression lines is still considerable, simple predictions of ecotoxicity between species are not possible . Correlation of LC50 (fish) and LD50 (rodent) indicates that toxicity is different . Surprisingly, the correlation of fish and rodent toxicity is not improved by transforming LC50 values to internal LD50s . The selection of ICCA chemicals by market significance (production volume) leads to a classification of toxicity, which is more comparable to a random sample of EINECS chemicals than to German BUA chemicals . The latter were chosen for concern (for Environment or Human Health) . RECOMMENDATIONS AND OUTLOOK: Of 147 dossiers assessed between SIAM 11-18, ca . 75% were sponsored by the three following countries: Germany (42), USA (37) and Japan (33) . The current output is about 50 dossiers per year (70-100 CAS-No), but a trend for an increase of output is noticeable . Industry, national authorities, and OECD work on a further development to speed up the output . The number of chemicals with 'low priority for further work' and the work recommended for the 'candidates' (mainly exposure assessment) indicate that the data presented were adequate for an initial hazard assessment according to OECD requirements . From the ICCA HPV list (n = 880, state of 1999) 44% of the chemicals have data available to cover all SIDS endpoints for Environment and only 33% for Human Health (Allanou et al . 1999) . This indicates the importance of the Initiative to provide information on existing chemicals . The authors agree with the expectation "...that the scientific information provided by this global initiative will be considered as an internationally accepted and harmonised basis for further steps of chemicals management." (ICCA 2002 b). Ann Chim, 2004 Sep-Oct, 94(9-10), 741 - 9 NH2-SEP-PAK cartridges for enrichment of Aromatic Sulfur Compounds from sea water: determination by GC-FID and GC-MS; Russo MV et al.; The Aromatic Sulfur Compounds (ASCs) are considered as "markers" of the crude oil age . In this frame, we have considered ASCs as "markers" of remote crude oil sea water pollution for their chemical characteristics, good solubility in water and resistance to the biodegradation . Gas chromatography of ASCs in distilled water and sea water samples has been performed after adsorption from a 80 mL water sample on to a cartridge containing 100 mg NH2-bonded porous silica . The ASCs are desorbed with 2 mL acetone-trichloromethane (1:1), which is concentrated and analysed by GC-FID or GC-MS in SIM mode . The average recovery of 0.1 microg mL(-1) of each ASC from distilled water and 0.04-0.2 microg mL(-1) from sea water samples is > or = 96.3% with a standard deviation < or = 2.2 . The limits of detection are 0.06-0.05 ng mL(-1) for thiophen-2-carboxaldehyde and benzothiophene, and 0.006-0.004 ng mL(-1) for dibenzothiophene and thiantrene in GC-FID whereas they are 0.02 ng mL(-1) for thiophen-2-carboxaldehyde and benzothiophene, and 0.003 ng mL(-1) for dibenzothiophene and thiantrene in GC-MS (SIM) with a relative standard deviation < or =7. Bioresour Technol, 2005 Mar, 96(5), 537 - 44 Comparative culturing of Pleurotus spp . on coffee pulp and wheat straw: biomass production and substrate biodegradation; Salmones D et al.; The results of the cultivation of six strains of Pleurotus (P . djamor (2), P . ostreatus (2) and P . pulmonarius (2)) on coffee pulp and wheat straw are presented . Metabolic activity associated with biomass of each strain was determined, as well as changes in lignin and polysaccharides (cellulose and hemicellulose), phenolic and caffeine contents in substrate samples colonized for a period of up to 36 days . Analysis were made of changes during the mycelium incubation period (16 days) and throughout different stages of fructification . Greater metabolic activity was observed in the wheat straw samples, with a significant increase between 4 and 12 days of incubation . The degradation of polysaccharide compounds was associated with the fruiting stage, while the reduction in phenolic contents was detected in both substrates samples during the first eight days of incubation . A decrease was observed in caffeine content of the coffee pulp samples during fruiting stage, which could mean that some caffeine accumulates in the fruiting bodies. Water Sci Technol, 2004, 50(5), 347 - 53 Assessment of microbial natural attenuation in groundwater polluted with gasworks residues; Schulze S et al.; Intrinsic biodegradation, representing the key process in Natural Attenuation, was examined at a tar-oil polluted disposal site . Methods to assess microbial natural attenuation of BTEX and PAH included analysis of groundwater hydrochemistry, pollutant profiles, composition of the microflora, and microcosm studies . In the polluted groundwater downgradient the disposal site, oxygen and nitrate were only available adjacent to the groundwater table and at the plume fringes . In the anaerobic core of the plume, a sequence of predominating redox zones (methanogenic, sulphate-reducing, Fe(III)-reducing) was observed . Changing pollutant profiles in the plume indicated active biodegradation processes, e.g . biodegradation of toluene and naphthalene in the anaerobic zones . High numbers of microorganisms capable of growing under anaerobic conditions and of aerobic pollutant degrading organisms confirmed the impact of biodegradation at this site . In microcosm studies, the autochthonous microflora utilised toluene, ethylbenzene, and naphthalene under sulfate- and Fe(III)-reducing conditions . Additionally, benzene and phenanthrene were degraded in the presence of Fe(III) . Under aerobic conditions, all BTEX and PAH were rapidly degraded . The microcosm studies in particular were suitable to examine the role of specific electron acceptors, and represented an important component of the multiple line of evidence concept to assess natural attenuation. Water Sci Technol, 2004, 50(5), 277 - 83 Bioavailability of a nonylphenol isomer in dependence on the association to dissolved humic substances; Vinken R et al.; Humic substances are important environmental components since they represent a very large part of organic compounds on earth . According to many reports, dissolved humic substances are a determinant parameter for the bioavailability of xenobiotic compounds . For the present bioavailability studies, two kinds of dissolved humic substances, a commercially available humic acid and fulvic acids isolated from peat were used . As the relevant xenobiotic, a defined branched nonylphenol isomer, 4(3',5'-dimethyl-3'-heptyl)-phenol (p353NP) was synthesised according to Friedel-Crafts alkylation . Equilibrium dialysis studies were implemented in order to investigate the association between 14C-labelled p353NP and dissolved humic substances . The biodegradability in the presence of dissolved humic substances was examined in experiments with the nonylphenol degrading bacterium strain Sphingomonas TTNP3 and with p353NP as sole carbon source . The results showed that p353NP-humic acid associates were formed in high amounts, whereas no adducts with fulvic acids occurred . In the degradation studies with Sphingomonas TTNP3, no effects of dissolved humic substances on the bioavailability of p353NP could be observed . It was assumed that the association between nonylphenol and humic acids occurs rapidly and is reversible . Thus, the formation of "labile" complexes did not influence biodegradation rates, which were quite low. Water Sci Technol, 2004, 50(5), 227 - 34 LC-MS-(MS) determination of oxidative degradation products of nonylphenol ethoxylates, carboxylates and nonylphenols in water; Petrovic M et al.; A commercial blend of nonylphenol ethoxylates (NPEOs) was chosen as representative for non-ionic polyethoxylated surfactants to study the oxidative degradation of this class of surfactants in water using ozonation as well as electron beam irradiation with and without the addition of ozone as treatment processes . The electron beam irradiation processes applied represent so-called Advanced Oxidation Processes (AOPs); the combined ozone/electron beam irradiation is, moreover, the most powerful AOP which can be applied in aqueous systems . It was found that both ozonation and the two AOPs applied were able to decompose not only the NPEOs but also the polyethyleneglycoles (PEGs) formed as by-products from NPEO degradation to residual concentrations below the limit of detection . Moreover, the treatment processes were also used to study the oxidative degradation of nonylphenoxy acetic acid (NPEC) and of nonylphenol (NP) which are formed as by-products from biodegradation of NPEOs. Water Sci Technol, 2004, 50(5), 85 - 92 BTE-OX biodegradation kinetics with MTBE through bioaugmentation; Acuna-Askar K et al.; The biodegradation kinetics of BTE-oX and MTBE, mixed all together, in the presence of bioaugmented bacterial populations as high as 880 mg/L VSS was evaluated . The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated . Biodegradation kinetics was evaluated for 36 hours, every 6 hours . Benzene and o-xylene biodegradation followed a first-order one-phase kinetic model, whereas toluene and ethylbenzene biodegradation was well described by a first-order two-phase kinetic model in all samples . MTBE followed a zero-order removal kinetic model in all samples . The presence of soil in aqueous samples retarded BTE-oX removal rates, with the highest negative effect on o-xylene . The presence of soil enhanced MTBE removal rate . The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples . Substrate percent removals ranged from 95.4-99.7% for benzene, toluene and ethylbenzene . O-xylene and MTBE percent removals ranged from 55.9-90.1% and 15.6-30.1%, respectively. J Environ Sci (China), 2004, 16(4), 694 - 6 A method to extract algae toxin of microcystin-LR; Zhang MM et al.; A simple and low-cost method to obtain cyanobacterial toxin microcystin-LR (MC-LR) was developed . A new strain of Microcystis aeruginosa, named DC-1, producing microcystin-LR but not microcystin-RR, was separated from the field blooming algae samples of Dianchi Lake, in southwest of China . Following three times' freeze and thaw treatment, the cultivated DC-1 cells were extracted with 40% methanol in water . The extract was centrifuged and the supernatant applied to a Hydrophilic-Lipophilic Balance (HLB) SPE cartridge . Eluted impurities with a certain gradient from 30% to 50% methanol in water, MC-LR was finally eluted from the HLB cartridge with 60% methanol in water, and samples containing 3.85% to 14.8% of MC-LR were obtained . These MC-LR samples may be used in adsorption and biodegradation experiments instead of using expensive standard reagents. Chemosphere, 2004 Nov, 57(7), 697 - 709 Effects of cross-substrate interaction on biotrickling filtration for the control of VOC emissions; Den W et al.; The effects of cross-substrate interaction to the performance of a gas-phase biotrickling filter for treating a mixture of volatile organic compounds (VOCs), including three structural heterologous in acetone, toluene, and trichloroethylene, were investigated . The biotrickling filter was inoculated with microbial consortium containing at least seven bacterial species utilizing either acetone or toluene, or both, as their carbon sources . In the performance study, the column operating under variable conditions typifying the waste gas emission from the microelectronics fabrication processes achieved a total hydrocarbon (THC) removal efficiency in excess of 85% and a mineralization capacity over 50% for THC mass loading as high as 36.2 g-CH4 m-3h-1 . The cross-substrate effects were examined by correlating the relative changes in the mass removal of each substrate with the biodegradative capability of the microbial consortium . The degradation of trichloroethylene was primarily due to co-metabolism by the toluene-oxidizing enzymes, but the results also indicated that trichloroethylene partially induced its own degradation . Concentration increases in acetone appeared to cause a diauxie effect that suppressed degradation of toluene and trichloroethylene, and shifted the microbial population toward the selective acetone-degraders . No irrecoverable toxicity or inhibitory effects were observed throughout the experiments . These results suggest that the relative VOC concentration in the waste gas mixture is a factor as important as the biodegradative function of the microbial consortium, and thus should be carefully evaluated to satisfy the treatment objectives . copyright 2004 Elsevier Ltd. Chemosphere, 2004 Nov, 57(7), 673 - 9 Influence of the application of sewage sludge on the degradation of pesticides in the soil; Sanchez ME et al.; A study was made of the influence of the application of sewage sludge on the degradation of pesticides in the soil . Two kinds of sludge were used, with different characteristics, one from an urban treatment plant and one from a food processing plant . Three organophosphorus insecticides, fenitrothion, diazinon and dimethoate, were studied . The relative importance was determined of the chemical and biological degradation processes, which involved experiments on soil and sterile soil samples . A comparative study was also made of the degradation of pesticide residues and the evolution of the microbial population . The application of sludge seems to have a complex effect on the degradation of pesticides, determined by the bioavailability and biodegradability of their active ingredient . The biodegradation of pesticide residues brings about alterations in the microorganism population of the soil . copyright 2004 Elsevier Ltd. Environ Sci Technol, 2004 Sep 15, 38(18), 4775 - 81 Pathway dependent isotopic fractionation during aerobic biodegradation of 1,2-dichloroethane; Hirschorn SK et al.; 1,2-Dichloroethane (1,2-OCA) is a widespread groundwater contaminant known to be biodegradable under aerobic conditions via enzymatic oxidation or hydrolytic dehalogenation reactions . Current literature reports that stable carbon isotope fractionation of 1,2-DCA during aerobic biodegradation is large and reproducible (-27 to -33/1000) . In this study, a significant variation in the magnitude of stable carbon isotope fractionation during aerobic biodegradation was observed . Biodegradation in experiments involving microcosms, enrichment cultures, and pure microbial cultures produced a consistent bimodal distribution of enrichment factors (epsilon) with one mean epsilon centered on -3.9 +/- 0.6/1000 and the other on -29.2 +/- 1.9/1000 . Reevaluation of epsilon in terms of kinetic isotope effects 12k/13k gave values of 12k/13k = 1.01 and 1.06, which are typical of oxidation and hydrolytic dehalogenation (S(N)2) reactions, respectively . The bimodal distribution is therefore consistent with the microbial degradation of 1,2-DCA by two separate enzymatic pathways . This interpretation is further supported in this study by experiments with pure strains of Xanthobacter autotrophicus GJ10, Ancylobacter aquaticus AD20, and Pseudomonas sp . Strain DCA1 for which the enzymatic degradation pathways are well-known . A small fractionation of -3.0/1000 was measured for 1,2-DCA degradation by Pseudomonas sp . Strain DCA1 (monooxygenase enzyme), while degradation by the hydrolytic dehalogenase enzyme by the other two pure strains was characterized by fractionation of -32.3/1000. Biotechnol Bioeng, 2004 Nov 5, 88(3), 379 - 91 Engineering cartilage-like tissue using human mesenchymal stem cells and silk protein scaffolds; Meinel L et al.; Human mesenchymal stem cells (hMSC) derived from bone marrow aspirates can form the basis for the in vitro cultivation of autologous tissue grafts and help alleviate the problems of immunorejection and disease transmission associated with the use of allografts . We explored the utility of hMSC cultured on protein scaffolds for tissue engineering of cartilage . hMSC were isolated, expanded in culture, characterized with respect to the expression of surface markers and ability for chondrogenic and osteogenic differentiation, and seeded on scaffolds . Four different scaffolds were tested, formed as a highly porous sponge made of: 1) collagen, 2) cross-linked collagen, 3) silk, and 4) RGD-coupled silk . Cell-seeded scaffolds were cultured for up to 4 weeks in either control medium (DMEM supplemented with 10% fetal bovine serum) or chondrogenic medium (control medium supplemented with chondrogenic factors) . hMSC attachment, proliferation, and metabolic activity were markedly better on slowly degrading silk than on fast-degrading collagen scaffolds . In chondrogenic medium, hMSC formed cartilaginous tissues on all scaffolds, but the extent of chondrogenesis was substantially higher for hMSC cultured on silk as compared to collagen scaffolds . The deposition of glycosaminoglycan (GAG) and type II collagen and the expression of type II collagen mRNA were all higher for hMSC cultured on silk than on collagen scaffolds . Taken together, these results suggest that silk scaffolds are particularly suitable for tissue engineering of cartilage starting from hMSC, presumably due to their high porosity, slow biodegradation, and structural integrity. Mund Kiefer Gesichtschir, 2004 Sep, 8(5), 277 - 81 Epub 2004 Jul 28. {Novel calcium phosphate formula for filling bone defects . Initial in vivo long-term results}; Henkel KO et al.; BACKGROUND: Up to now hydroxyapatite (HA) and beta-tricalciumphosphate (beta-TCP) ceramics have been routinely sintered at temperatures between 1100 degrees and 1500 degrees C . Our new calcium ceramic is fabricated by a sol-gel process at 200 degrees C . The aim of this investigation was to test the biodegradation of and the induction of bone formation by this material . MATERIAL AND METHODS: Eighteen 1-year-old Goettingen minipigs were divided into three groups . Critical size defects (>5 cm(3)) in the mandible were treated differently in all three animals (group 1: filling with 40% beta-TCP plus 60% HA, group 2: pure HA was applied, group 3 served as controls: only gelatinous material was given) . Macroscopic and microscopic investigations of the former defects were made 8 months postoperatively . RESULTS . In groups 1 and 2 biodegradation of more than 93% of the new calcium phosphate formula was found 8 months postoperatively and considered to be very good . No difference was observed between pure HA (group 2) and the combination of HA and beta-TCP (group 1) . In both groups complete bone formation was seen macroscopically in the former defects . In the control group only incomplete bone formation with 48.4% of the defect area was noted . This difference was significant ( p<0.001) . DISCUSSION: The new calcium phosphate formula made by a sol-gel method at 120 degrees C seems to be suitable for filling bone defects and is of interest for orthopedic surgery, traumatology, craniomaxillofacial surgery, and dentistry. J Agric Food Chem, 2004 Oct 20, 52(21), 6402 - 13 Degradation studies on benzoxazinoids . Soil degradation dynamics of 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA) and its degradation products, phytotoxic allelochemicals from gramineae; Macias FA et al.; Benzoxazinoids have been described as important allelochemicals from Gramineae as well as Acanthaceae, Rannunculaceae, and Scrophulariaceae plants . Several bioactivities have been described and evaluated for these compounds, including fungistatic, antifeedant, and phytotoxic . In ongoing studies about allelochemicals as natural herbicide models, the description of soil dynamics in phytotoxic agents has high importance, because the possible biotransformations developed by soil microorganisms could yield compounds with modified biological properties, affecting the overall allelopathic capability of the producer plant in a direct manner . Thus, a complete degradation study has been carried out for 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA) and 6-methoxybenzoxazolin-2(3H)-one (MBOA) in two soils cultivated with Triticum aestivum L . varieties (cv . Astron and cv . Ritmo) . The main purpose was to identify degradation products and to elucidate biotransformation dynamics . Results show DIMBOA to degrade rapidly, yielding MBOA in both studied soils at different doses (t(1/2) = 31 +/- 1 h, n = 12) and reaching high conversions (80 +/- 4 h, n = 42) . MBOA, an intermediate in the degradation pathway from DIMBOA to 2-amino-7-methoxy-3H-phenoxazin-3-one (AMPO), was more resistant toward biodegradation (t(1/2) = 5 +/- 1 days, n = 6) . MBOA showed maximum conversions at a dose of 250 mg/kg of soil (36 +/- 3 days, n = 6) . Soil belonging to T . aestivum cv . Ritmo crops showed higher degradation capacity than cv . Astron soil . AMPO was the final degradation product observed for DIMBOA in the soils and experimental conditions selected . Consequences for activity and stability of these compounds in relation to allelopathy are discussed . Ultrason Sonochem, 2005 Jan, 12(1-2), 121 - 5 Ultrasonic dehalogenation and toxicity reduction of trichlorophenol; Tiehm A et al.; The study focussed on the effect of ultrasonic frequency and co-pollutants on dechlorination and toxicity reduction of a toxic model pollutant, i.e . 2,3,5-trichlorophenol (TCP) . The effect of ultrasonic frequency on TCP degradation and chloride formation was studied at 41, 206, 360, 618, 1068, and 3217 kHz . Most efficient ultrasonic dechlorination was achieved at 360 kHz . The degradation of TCP and adsorbable organic halogens followed pseudo-first-order rate kinetics . Toxicity in the bioluminescence test increased during the initial sonication period, indicating the temporary formation of more toxic reaction products . Subsequently, toxicity was significantly reduced . Dehalogenation efficiency decreased in the presence of the hydrophobic radical scavenger t-butanol, whereas hydrophilic co-pollutants such as acetate or glucose did not interfere with ultrasonic dechlorination and toxicity reduction . After ultrasonic pre-treatment, a fast biodegradation of the remaining organic pollutants was observed . In conclusion, the results demonstrate the potential of integrated ultrasonic/biological approaches for the treatment of wastewaters containing toxic pollutants. Biodegradation, 2004 Aug, 15(4), 213 - 27 Effect of benzene, toluene, ethylbenzene, and p-xylene (BTEX) mixture on biodegradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) by pure culture UC1; Pruden A et al.; The effect of a BTEX mixture on the biodegradation of methyl tert-butyl ether (MTBE) and its degradation intermediate, tert-butyl alcohol (TBA) was investigated in the pure bacterial culture UC1, which has been identified to be a strain of the known MTBE-degrader PM1 based on greater than 99% 16S rDNA similarity . Several degradation studies were carried out on UC1 at three initial concentration levels of MTBE or TBA: 6-7; 15-17; and 40-45 mg/l, both with and without BTEX present cumulatively at about half of the MTBE or TBA molar mass in the system . The BTEX mixture was observed not to affect either the rate or the degradation lag period of MTBE or TBA degradation, except that the TBA degradation rate actually increased when BTEX was present initially in the highest concentration studies . When serving as the sole substrate, the MTBE degradation rate ranged from 48 +/- 1.2 to 200 +/- 7.0 mg(MTBE)/g(dw) h, and the TBA degradation rate from 140 +/- 18 to 530 +/- 70 mg(TBA)/g(dw) h . When present with BTEX, MTBE and TBA rates ranged from 46 +/- 2.2 to 210 +/- 14 and 170 +/- 28 to 780 +/- 43 mg(TBA)/g(dw) h, respectively . In studies where varying concentrations of TBA were present with 5 mg/l MTBE, both compounds were degraded simultaneously with no obvious preference for either substrate . In the highest concentration study of TBA with 5 mg/l MTBE, BTEX was also observed to increase the ultimate rate of TBA degradation . In addition to exploring the affect of BTEX, this study also provides general insight into the metabolism of MTBE and TBA by pure culture UC1. Macromol Biosci, 2004 Mar 15, 4(3), 218 - 31 Environmentally degradable bio-based polymeric blends and composites; Chiellini E et al.; Blends and composites based on environmentally degradable-ecocompatible synthetic and natural polymeric materials and fillers of natural origin have been prepared and processed under different conditions . Poly(vinyl alcohol) (PVA) was used as the synthetic polymer of choice by virtue of its capability to be processed from water solution or suspension as well as from the melt by blow extrusion and injection molding . Starch and gelatin were taken as the polymeric materials from renewable resources . The fillers were all of natural origin, as waste from food and agro-industry consisted of sugar cane bagasse (SCB), wheat flour (WF), orange peels (OR), apple peels (AP), corn fibres (CF), saw dust (SD) and wheat straw (WS) . All the natural or hybrid formulations were intended to be utilized for the production of: a) Environmentally degradable mulching films (hydro-biomulching) displaying, in some cases, self-fertilizing characteristics by in situ spraying of water solutions or suspensions; b) Laminates and containers to be used in agriculture and food packaging by compression and injection molding followed by baking.Some typical prototype items have been prepared and characterized in relation to their morphological and mechanical properties and tested with different methodology for their propensity to environmental degradation and biodegradation as ultimate stage of their service life . A relationship between chemical composition and mechanical properties and propensity to biodegradation has been discussed in a few representative cases. Macromol Biosci, 2004 Mar 15, 4(3), 208 - 17 Degradable polyesters through chain linking for packaging and biomedical applications; Seppala JV et al.; The major route to convert lactic acid to high-molecular-weight polymers is ring-opening polymerization of lactide . We have investigated alternative synthesis routes based on oligomerization and chain linking to produce high-molecular-weight thermoplastic degradable polymers cost-effectively . Chain linking also offers new possibilities to prepare degradable polyesters for biomedical applications by extending the range of polymer properties achievable . In this paper, we briefly review different chain linking techniques used in our laboratory . Typically, lactic acid prepolymers with molecular weights of around 3,000-15,000 g x mol(-1) have been prepared by direct polycondensation . Hydroxyl terminated oligomers have been chain linked by using diisocyanate coupling agents, preferably 1,4-butane diisocyanate, forming poly(ester-urethanes) . Poly(ester-amides) have been prepared by using 2,2'-bis(2-oxazoline) as coupling agent for carboxylic acid telechelic oligomers . Chain linking by end functionalization has been used in the preparation of poly(ester-anhydrides) . In addition, a variety of crosslinked degradable polymers and copolymers have been synthesized through different crosslinking routes, by using methacrylic, itaconic or maleic double bonds or triethoxysilane moieties . A biodegradation test and ecotoxicological evaluation of the degradation products were carried out in addition to hydrolysis tests . Lactic acid based chain linked polymers were biodegradable and the degradation products were harmless . In hydrolysis tests, enzymatic degradation was pronounced in the chain linked poly(epsilon-caprolactone). Appl Environ Microbiol, 2004 Oct, 70(10), 6031 - 6 Accelerated biodegradation of cement by sulfur-oxidizing bacteria as a bioassay for evaluating immobilization of low-level radioactive waste; Aviam O et al.; Disposal of low-level radioactive waste by immobilization in cement is being evaluated worldwide . The stability of cement in the environment may be impaired by sulfur-oxidizing bacteria that corrode the cement by producing sulfuric acid . Since this process is so slow that it is not possible to perform studies of the degradation kinetics and to test cement mixtures with increased durability, procedures that accelerate the biodegradation are required . Semicontinuous cultures of Halothiobacillus neapolitanus and Thiomonas intermedia containing thiosulfate as the sole energy source were employed to accelerate the biodegradation of cement samples . This resulted in a weight loss of up to 16% after 39 days, compared with a weight loss of 0.8% in noninoculated controls . Scanning electron microscopy of the degraded cement samples revealed deep cracks, which could be associated with the formation of low-density corrosion products in the interior of the cement . Accelerated biodegradation was also evident from the leaching rates of Ca(2+) and Si(2+), the major constituents of the cement matrix, and Ca exhibited the highest rate (up to 20 times greater than the control rate) due to the reaction between free lime and the biogenic sulfuric acid . Leaching of Sr(2+) and Cs(+), which were added to the cement to simulate immobilization of the corresponding radioisotopes, was also monitored . In contrast to the linear leaching kinetics of calcium, silicon, and strontium, the leaching pattern of cesium produced a saturation curve similar to the control curve . Presumably, the leaching of cesium is governed by the diffusion process, whereas the leaching kinetics of the other three ions seems to governed by dissolution of the cement. Biotechnol Prog, 2004 Sep-Oct, 20(5), 1588 - 92 Predicting dye biodegradation from redox potentials; Zille A et al.; Two biological approaches for decolorization of azo sulfonated dyes have been compared: reductive decolorization with the ascomycete yeast Issatchenkia occidentalis and enzymatic oxidative decolorization with Trametes villosa laccase alone or in the presence of the mediator 1-hydroxybenzotriazole . The redox potential difference between the biological cofactor involved in the reductive activity of growing cells and the azo dye is a reliable indication for the decolorization ability of the biocatalyst . A linear relationship exists between the redox potential of the azo dyes and the decolorization efficiency of enzyme, enzyme/mediator, and yeast . The less positive the anodic peak of the dye, the more easily it is degraded oxidatively with laccase . The more positive the cathodic peak of the dye, the more rapidly the dye molecule is reduced with yeast. Analyst, 2004 Oct, 129(10), 956 - 62 Epub 2004 Aug 23. Raman spectroscopic analyses of preserved historical specimens of human hair attributed to Robert Stephenson and Sir Isaac Newton; Edwards HG et al.; The Raman spectra of two historical specimens of human hair attributed to the engineer Robert Stephenson and scientist Sir Isaac Newton, preserved in private collections are reported . Comparisons are made with the Raman spectra of modern hair specimens and with hair from archaeological excavations . The hair spectra collected with a laser excitation of 785 nm are of a better quality than those collected using 1064 nm . The historical hair specimens are remarkably well-defined spectroscopically in terms of the amide I vibrational mode and the {small nu}(SS), ascribed to a predominantly gauche-gauche-gauche CSSC conformation . The contrast with degraded hair specimens recovered from archaeological excavations is striking . The presence of a weak feature near 2590 cm(-1) in the hair samples attributed to a {small nu}(SH) vibration could be indicative of a reduction process operative on the CSSC cystine keratotic linkages and a possible origin of this is bacterial biodegradation identified histologically . This study demonstrates the molecular information available from non-destructive Raman spectroscopic analysis from single hair shafts or small bundles of fibres which complements information available from histological and destructive analytical techniques for rare biological specimens subjected to conservation or curation procedures in museums or private collections. J Agric Food Chem, 2004 Oct 6, 52(20), 6233 - 8 Isomer selectivity in aquatic toxicity and biodegradation of cypermethrin; Liu W et al.; Synthetic pyrethroids (SPs) are widely used in both agricultural and urban regions for insect control . Unlike many other pesticides, SPs are chiral compounds consisting of stereoisomers . However, occurrence of isomer selectivity in environmental processes is poorly understood for SPs . We evaluated isomer selectivity in toxicity of cypermethrin (CP) to Ceriodaphnia dubia and in its biodegradation by microbial isolates and in sediment . Among the eight enantiomers, two enantiomers (1R-cis-alphaS and 1R-trans-alphaS) were found to be toxic to C . dubia . Bacteria strains isolated from sediment selectively degraded CP diastereomers and enantiomers . The trans diastereomers were preferentially degraded over the cis diastereomers . Of the two active enantiomers, 1R-cis-alphaS was degraded slower, whereas 1R-trans-alphaS was degraded faster than the other stereoisomers . Similar isomer selectivity was observed during CP degradation in whole sediment . Since ecotoxicity is likely caused only by the biologically active enantiomers, knowledge on isomer selectivity may improve our understanding of the ecological risks of CP and analogous SPs. J Chromatogr A, 2004 Sep 3, 1048(1), 67 - 71 Development of a static headspace gas chromatographic/mass spectrometric method to analyze the level of volatile contaminants biodegradation; Sakata SK et al.; Volatile compound biodegradation analysis usually requires the time-consuming step of extraction of the analytes from the matrix using organic solvents or costly radioactive-compounds . Thus, it is desirable to have a simple and fast technique to generate a good evaluation of bacterial biodegradation . The goal of this research was to develop a methodology on the basis of static headspace-gas chromatography/mass spectrometry (HS-GC/MS) to evaluate the level of volatile contaminant biodegradation . The effects of the following parameters were studied: temperature and time of equilibration . The biodegradation experiments were carried out with bacteria inoculation in mineral media in presence of volatile hydrocarbon compounds (toluene, p-xylene, nonane and naphthalene) . Autoclaved inoculates were used as control and reference sample . The optimal headspace conditions were observed when the vials were heated at 80 degrees C for 20 min, the syringe at 81 degrees C and an injection volume of 0.4 mL was used . This methodology has the advantage of being relative free from matrix effects. Proteomics, 2004 Nov, 4(11), 3610 - 21 Proteome analysis of Pseudomonas sp . K82 biodegradation pathways; Kim SI et al.; Pseudomonas sp . K82 is a soil bacterium that can degrade and use monocyclic aromatic compounds including aniline, 3-methylaniline, 4-methylaniline, benzoate and p-hydroxybenzoate as its sole carbon and energy sources . In order to understand the impact of these aromatic compounds on metabolic pathways in Pseudomonas sp . K82, proteomes obtained from cultures exposed to different substrates were displayed by two-dimensional gel electrophoresis and were compared to search for differentially induced metabolic enzymes . Column separations of active fractions were performed to identify major biodegradation enzymes . More than thirty proteins involved in biodegradation and other types of metabolism were identified by electrospray ionization-quadrupole time of flight mass spectrometry . The proteome analysis suggeste