J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002, 37(4), 553 - 62 Effect and mechanism of inorganic carbon on the biodegradation of dimethyl phthalate by Chlorella pyrenoidosa; Yan H et al.; The effect and mechanism of inorganic carbon (IC) on the biodegradation of dimethyl phthalate (DMP) by a green microalga Chlorella pyrenoidosa was investigated . It was indicated that DMP could be used as the sole carbon source to support the slow heterotrophic growth of C . pyrenoidosa, but both the growth of C . pyrenoidosa and the biodegradation rate of DMP were obviously increased when initial inorganic carbon concentration (IC) was increased from 0.6 to 23.7 mg/l . Phthalic acid (PA) was found to be an intermediate product of DMP biodegradation and accumulated in the culture solution, which caused a sharp decrease in pH of medium and inhibited both the growth of alga and the biodegradation of DMP . The role of IC for improving the biodegradation of DMP was both to supply a favorite carbon source to support the rapid growth of alga and to mitigate the decrease of pH because of the production of PA . A suggested second-order kinetic equation of organic pollutant biodegradation by microalgae (-dC/dt = KNr) fitted well with the experimental data and the correlation coefficients were all above 0.9 . The second-order constant (K) apparently declined with the increase of initial IC because lower ratio between organic carbon from DMP and IC was used to support the growth of alga when initial IC increased. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002, 37(4), 425 - 38 Abatement of gas-condensate hydrocarbons in a natural wetland; Moore BJ et al.; Results of a five-year research study on natural attenuation processes in a wetland, located downgradient of a sour gas processing plant in central Alberta, Canada, show that natural attenuation may present a favourable remedial solution . Both free-phase and dissolved phase condensate have been discharging to the wetland since 1984 . This condensate is primarily composed of C5 to C12 hydrocarbons, including BTEX compounds . The condensate enters the base of the wetland at 1 m below ground surface, resulting in contamination of the wetland peat and underlying clay till . The lateral extent of contamination in the wetland has remained stable, and apparent free product thickness and BTEX concentrations have decreased over time . Sorption, aerobic biodegradation, volatilization, and anaerobic biodegradation were identified as active attenuation processes at this site . Sorption and desorption processes were evaluated by laboratory testing of site soils using 14C-benzene . Linear sorption coefficients (Kd) for the surface and subsurface peat were similar (4.48-4.62 l/kg), while the Kd for the underlying silt was 0.096 l/kg . The significantly higher Kd values for the peat are attributed to the peat's higher organic content (40%), relative to the clayey silt (1%) . No significant resistance to desorption was observed, however, indicating that benzene would remain mobile and bioavailable over time . Aerobic biodegradation and volatilization appear to be the main removal processes . They are enhanced by a seasonal drop in the water level from surface down to 1 m depth, resulting in an aerobic unsaturated zone . Respiration testing in the peat indicates a significant aerobic biodegradation rate of 27 mg/kg/day, equating to an estimated hydrocarbon removal rate of 5 kg/day across the 3600 m2 plume area . Surface vapour measurements indicate hydrocarbon volatilization is occurring at a rate of 3 x 10(-4) kg/m2/day, equating to a mass removal of 1 kg/day across the plume . Anaerobic biodegradation is occurring primarily in the clayey silt, based on geochemical indicator parameters, microbial analyses, and soil vapour sampling . Overall, natural attenuation appears to be a feasible remedial solution for this wetland, by providing continued removal and degradation of condensate components before they reach the downgradient surface water receptor. Water Res, 2002 Apr, 36(7), 1843 - 53 Physical modelling of solute transport in porous media: evaluation of an imaging technique using UV excited fluorescent dye; Huang WE et al.; The development and evaluation of a 2-dimensional physical model, which is designed to assist in the characterisation of complex solute transport problems in porous media, is described . The laboratory model is a transparent 2-dimensional porous media of nominal thickness and uses a non-invasive imaging technique in conjunction with a fluorescent dye tracer (sodium fluorescein) to monitor solute movements . Under ultraviolet (UV) illumination the dye emits visible light which is imaged by a CCD (Charge Coupled Device) camera . The image is processed to estimate the 2-dimensional distribution of tracer concentrations . The system can successfully model a simple contaminant plume within a homogenous porous matrix constructed from glass beads (60-100 microm) . Experimental results show that transverse dispersion coefficient was 3.9 x 10(-10) m2/s when sodium fluorescein transported in porous matrix with a walter velocity of 5.71 x 10(-6) m/s . The low transverse dispersion coefficient suggests that the molecular diffusion of solute cannot be neglected under low velocity of the water . The advantages of using UV rather than an ordinary light system are a reduction in noise and experimental errors . Errors due to light dispersion within the model are shown to be negligible for the current model . Since contaminant with aromatic rings are usually fluorescent and biological samples can be labelled by fluorescent dye, this imaging technique using UV excited fluorescent dye will be used to investigate biodegradation process in porous media. Water Res, 2002 Apr, 36(7), 1707 - 14 Biodegradation of propylene glycol and associated hydrodynamic effects in sand; Bielefeldt AR et al.; At airports around the world, propylene glycol (PG) based fluids are used to de-ice aircraft for safe operation . PG removal was investigated in 15-cm deep saturated sand columns . Greater than 99% PG biodegradation was achieved for all flow rates and loading conditions tested, which decreased the hydraulic conductivity of the sand by 1-3 orders of magnitude until a steady-state minimum was reached . Under constant loading at 120 mg PG/d for 15-30 d, the hydraulic conductivity (K) decreased by 2-2.5 orders of magnitude when the average linear velocity of the water was 4.9-1.4 cm/h . Variable PG loading in recirculation tests resulted in slower conductivity declines and lower final steady-state conductivity than constant PG feeding . After significant sand plugging, endogenous periods of time without PG resulted in significant but partial recovery of the original conductivity . Biomass growth also increased the dispersivity of the sand. Appl Environ Microbiol, 2002 Jun, 68(6), 2754 - 62 Biodegradation of methyl tert-butyl ether and other fuel oxygenates by a new strain, Mycobacterium austroafricanum IFP 2012; Francois A et al.; A strain that efficiently degraded methyl tert-butyl ether (MTBE) was obtained by initial selection on the recalcitrant compound tert-butyl alcohol (TBA) . This strain, a gram-positive methylotrophic bacterium identified as Mycobacterium austroafricanum IFP 2012, was also able to degrade tert-amyl methyl ether and tert-amyl alcohol . Ethyl tert-butyl ether was weakly degraded . tert-Butyl formate and 2-hydroxy isobutyrate (HIBA), two intermediates in the MTBE catabolism pathway, were detected during growth on MTBE . A positive effect of Co2+ during growth of M . austroafricanum IFP 2012 on HIBA was demonstrated . The specific rate of MTBE degradation was 0.6 mmol/h/g (dry weight) of cells, and the biomass yield on MTBE was 0.44 g (dry weight) per g of MTBE . MTBE, TBA, and HIBA degradation activities were induced by MTBE and TBA, and TBA was a good inducer . Involvement of at least one monooxygenase during degradation of MTBE and TBA was shown by (i) the requirement for oxygen, (ii) the production of propylene epoxide from propylene by MTBE- or TBA- grown cells, and (iii) the inhibition of MTBE or TBA degradation and of propylene epoxide production by acetylene . No cytochrome P-450 was detected in MTBE- or TBA-grown cells . Similar protein profiles were obtained after sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude extracts from MTBE- and TBA-grown cells . Among the polypeptides induced by these substrates, two polypeptides (66 and 27 kDa) exhibited strong similarities with known oxidoreductases. Appl Environ Microbiol, 2002 Jun, 68(6), 2726 - 30 Biodegradation of cis-dichloroethene as the sole carbon source by a beta-proteobacterium; Coleman NV et al.; An aerobic bacterium capable of growth on cis-dichloroethene (cDCE) as a sole carbon and energy source was isolated by enrichment culture . The 16S ribosomal DNA sequence of the isolate (strain JS666) had 97.9% identity to the sequence from Polaromonas vacuolata, indicating that the isolate was a beta-proteobacterium . At 20 degrees C, strain JS666 grew on cDCE with a minimum doubling time of 73 +/- 7 h and a growth yield of 6.1 g of protein/mol of cDCE . Chloride analysis indicated that complete dechlorination of cDCE occurred during growth . The half-velocity constant for cDCE transformation was 1.6 +/- 0.2 microM, and the maximum specific substrate utilization rate ranged from 12.6 to 16.8 nmol/min/mg of protein . Resting cells grown on cDCE could transform cDCE, ethene, vinyl chloride, trans-dichloroethene, trichloroethene, and 1,2-dichloroethane . Epoxyethane was produced from ethene by cDCE-grown cells, suggesting that an epoxidation reaction is the first step in cDCE degradation. Appl Environ Microbiol, 2002 Jun, 68(6), 2699 - 703 An NADH:quinone oxidoreductase active during biodegradation by the brown-rot basidiomycete Gloeophyllum trabeum; Jensen Jr KA Jr et al.; The brown-rot basidiomycete Gloeophyllum trabeum uses a quinone redox cycle to generate extracellular Fenton reagent, a key component of the biodegradative system expressed by this highly destructive wood decay fungus . The hitherto uncharacterized quinone reductase that drives this cycle is a potential target for inhibitors of wood decay . We have identified the major quinone reductase expressed by G . trabeum under conditions that elicit high levels of quinone redox cycling . The enzyme comprises two identical 22-kDa subunits, each with one molecule of flavin mononucleotide . It is specific for NADH as the reductant and uses the quinones produced by G . trabeum (2,5-dimethoxy-1,4-benzoquinone and 4,5-dimethoxy-1,2-benzoquinone) as electron acceptors . The affinity of the reductase for these quinones is so high that precise kinetic parameters were not obtainable, but it is clear that k(cat)/K(m) for the quinones is greater than 10(8) M(-1) s(-1) . The reductase is encoded by a gene with substantial similarity to NAD(P)H:quinone reductase genes from other fungi . The G . trabeum quinone reductase may function in quinone detoxification, a role often proposed for these enzymes, but we hypothesize that the fungus has recruited it to drive extracellular oxyradical production. Microb Ecol, 2000 Apr, 39(3), 203 - 210 Structure of a Natural Microbial Community in a Nitroaromatic Contaminated Groundwater Is Altered during Biodegradation of Extrinsic, but Not Intrinsic Substrates; Wikstrom P et al.; A BSTRACTThis study demonstrates microbial community changes over time in a nitroaromatic-contaminated groundwater upon amendment with hydrocarbons previously unknown to the microbial community (extrinsic) and hydrocarbons previously known to the microbial community (intrinsic) . Sealed flasks, shaken and incubated at 25 degrees C, containing contaminated groundwater and salts were amended twice with extrinsic hydrocarbons including phenol, benzoic acid, and naphthalene, and intrinsic hydrocarbons including 2,4-dinitrotoluene (2,4-DNT) and para-nitrotoluene ( p-NT) . Microbial growth, biodegradation, and community structure changes measured by random amplified polymorphic DNA (RAPD) and quantitative PCR (qPCR) targeting catechol-2,3-dioxygenase (C23O) genes were monitored over time . All amended substrates were biodegraded after both substrate amendments except for 2,4-DNT, which was only partially degraded after the second amendment . Unique microbial communities were developed in flasks amended with phenol, benzoic acid, and naphthalene . However, in the flasks amended with intrinsic hydrocarbons the microbial community remained similar to the unamended control flasks . The relative amount of C23O genes detected by qPCR correlated with the biodegradation of phenol and naphthalene but not with 2,4-DNT . The results showed that a selection for microorganisms capable of catabolizing extrinsic hydrocarbons naturally and initially present in the nitroaromatic-contaminated groundwater occurred . However, growth-linked biodegradation of added intrinsic hydrocarbons was not selective. Environ Sci Technol, 2002 May 1, 36(9), 1931 - 8 Carbon and hydrogen isotopic fractionation during biodegradation of methyl tert-butyl ether; Gray JR et al.; Carbon and hydrogen isotopic fractionation during aerobic biodegradation of MTBE by a bacterial pure culture (PM1) and a mixed consortia from Vandenberg Air Force Base (VAFB) were studied in order to assess the relative merits of stable carbon versus hydrogen isotopic analysis as an indicator of biodegradation . Carbon isotopic enrichment in residual MTBE of up to 8.1/1000 was observed at 99.7% biodegradation . Carbon fractionation was reproducible in the PM1 and VAFB experiments, yielding similar enrichment factors (epsilon) of -2.0/1000 +/- 0.1/1000 to -2.4/1000 +/- 0.3/1000 for replicates in the PM1 experiment and -1.5/1000 +/- 0.1/1000 to -1.8/1000 +/- 0.1/1000 for replicates in the VAFB experiment . Hydrogen isotopic fractionation was highly reproducible for the PM1 pure cultures, with epsilon values of -33/1000 +/- 5/1000 to -37/1000 +/- 4/1000 for replicate samples . In the VAFB microcosms, there was considerably more variability in epsilon values, with values of -29/1000 +/- 4/1000 and -66/1000 +/- 3/1000 measured for duplicate sample bottles . Despite this variability, hydrogen isotopic fractionation always resulted in 2H enrichment of the residual MTBE of >80/1000 at 90% biodegradation . The reproducible carbon fractionation suggests that compound-specific carbon isotope analysis may be used to estimate the extent of biodegradation at contaminated sites . Conversely, the large hydrogen isotopic fractionation documented during biodegradation of MTBE suggests that compound-specific hydrogen isotope analysis offers the most conclusive means of identifying in-situ biodegradation at contaminated sites. Mikrobiologiia, 2002 Mar-Apr, 71(2), 258 - 63 {The biodegradation of poly-beta-hydroxybutyrate (PHB) by a model soil community: the effect of cultivation conditions on the degradation rate and the physicochemical characteristics of PHB}; Bonartseva GA et al.; The biodegradation of films made of poly-beta-hydroxybutyrate (PHB) with a molecular mass of 1500 kDa was studied using a model soil community in the presence and absence of nitrate and at different concentrations of oxygen in the gas phase . The biodegradation of PHB was investigated with respect to changes in its molecular mass, crystallinity, and some mechanical properties. Microb Ecol, 2001 Oct, 42(3), 256 - 266 Water Content Mediated Microaerophilic Toluene Biodegradation in Arid Vadose Zone Materials; Holden PA et al.; We investigated the conditions promoting toluene biodegradation for gasoline-contaminated near-surface (0.6 m depth) and subsurface (4.7 to 5.0 m depth) vadose zone soils sampled from an arid environment . At both depths, water addition was required for toluene biodegradation to occur . In near-surface samples, no inorganic nutrient addition was necessary and (i) biodegradation was fastest at 0.0 MPa, (ii) biodegradation rates decreased with decreasing water potential down to ?1.0 MPa, and (iii) biodegradation was undetectable at ?1.5 MPa . For subsurface material, toluene depletion was stimulated either by slurrying with a nutrient solution or by adjusting the moisture content to 20% (0.0 MPa) with nutrient solution and lowering the oxygen concentration (to effectively 1 mg L-1 in the aqueous phase) . Thus, in the subsurface material, toluene depletion was microaerobic and nutrient-limited, occurring only under low oxygen and with inorganic nutrient addition . Our studies implicate microaerophily as an important characteristic of the toluene-degrading communities in these dry soils, with soil water as a primary controller of oxygen availability. Appl Microbiol Biotechnol, 2002 May, 58(6), 848 - 52 Epub 2002 Mar 16. Biodegradation of triazine herbicides on polyvinylalcohol gel plates by the soil yeast Lipomyces starkeyi; Nishimura K et al.; The soil yeast Lipomyces starkeyi was tested for its ability to degrade triazine herbicides . Polyvinylalcohol (PVA) was employed as a solid medium in culture plates instead of agar . The cell sizes of the control (without nitrogen source) on the PVA gel plate were much smaller than those on the agar gel plate . The difference between the diameters of the sample and control colonies on the PVA gel plate were almost twice those of the colonies on the agar gel plate (1.9 and 1.0 mm, respectively) . Thus, the PVA gel plate is much better than the agar plate for evaluating the degree of utilization of a sole nitrogen source . The yeast grew well (more than 4 mm in diameter) with 1,3,5-triazine or cyanuric acid as nitrogen source . In addition, melamine and thiocyanuric acid inhibited growth of the yeast, and the sizes of colonies were smaller than those of the control . All triazine herbicides tested (simazine, atrazine, cyanazine, ametryn, and prometryn) could be degraded and assimilated by L . starkeyi. FEMS Microbiol Lett, 2002 Mar 19, 209(1), 107 - 11 Use of NIR and pyrolysis-MBMS coupled with multivariate analysis for detecting the chemical changes associated with brown-rot biodegradation of spruce wood; Kelley SS et al.; Near infrared (NIR) spectroscopy and pyrolysis-molecular beam mass spectrometry (py-MBMS) analysis can be used in conjunction with multivariate regression and principal components analysis to differentiate brown-rot-degraded wood from non-degraded spruce and to follow the temporal changes in wood undergoing brown-rot degradation . Regression of NIR test results vs . percent weight loss for Postia placenta- and Gloeophyllum trabeum-infected spruce wood blocks yielded a correlation coefficient of 0.96 . Regression of MBMS test results for the same samples yielded a correlation coefficient of 0.96 . Principle components analysis was used to differentiate non-infected wood and P . placenta- and G . trabeum-infected wood . These techniques may be used to detect different types of biodegradation and to develop a better understanding of the chemical changes that the wood undergoes when it is subjected to brown-rot biodegradation. Chembiochem, 2002 May 3, 3(5), 424 - 32 On the biodegradation of beta-peptides; Schreiber JV et al.; A consortium of microorganisms was established that was able to grow with the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, with the beta-dipeptide H-beta-HAla-beta-HLeu-OH, and with the beta-amino acids H-beta-HAla-OH, H-beta-HVal-OH, and H-beta-HLeu-OH as the sole carbon and energy sources . This growth was achieved after several incubation-transfer cycles with the beta-tripeptide as the substrate . During degradation of the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, the temporary formation of a metabolite was observed . The metabolite was identified as the beta-dipeptide H-beta-HAla-beta-HLeu-OH by nuclear magnetic resonance spectroscopy and mass spectrometry . This result indicates that in the course of the degradation of the beta-tripeptide, the N-terminal beta-HVal residue was cleaved off by a not yet known mechanism . During the subsequent degradation of the beta-dipeptide, formation of additional metabolites could not be detected . The growth-yield coefficients Y(x/s) for growth on the beta-di- and beta-tripeptide both had a value of 0.45 . When a 1:1 mixture of the beta-tripeptide and the corresponding alpha-tripeptide H-Val-Ala-Leu-OH was added to the enrichment culture, the alpha-peptide was completely utilized in six days and thereafter growth of the culture stopped . This result indicates that even in beta-peptide enrichment cultures, alpha-peptides are the preferred substrates . Our experiments clearly show for the first time that beta-peptides and beta-amino acids are amenable to biodegradation and that a microbial consortium was able to utilize these compounds as sole carbon and energy sources . Furthermore, the preparation of beta-amino acids, of derivatives thereof, and of beta-di- and beta-tripeptides is described. Bioresour Technol, 2002 Apr, 82(2), 151 - 6 Anaerobic removal of linear alcohol ethoxylates; Mezzanotte V et al.; The present paper deals with a laboratory-scale study of anaerobic treatment of two commercial mixtures (LS2, LT7) of alcohol ethoxylates with 8-14 carbon atoms and 2 and 7 ethoxy groups . Tests were carried out in batch, with a 2 g l(-1) single dose, and in semibatch, with daily 0.2 g l(-1) doses . The behaviour of the tested mixtures was different: anaerobic sludge adsorption was the main removal process for LS2, while adsorption was less significant and biodegradation was more important for LT7 . These differences appeared to be mainly related to the ethoxy portion length determining the extent of biodegradability and adsorption. Bioresour Technol, 2002 Apr, 82(2), 115 - 21 Anaerobic digestion of alcohol sulfate (anionic surfactant) rich wastewater--batch experiments . Part I: influence of the surfactant concentration; Feitkenhauer H et al.; Textile wet processing wastewater (e.g., from cotton desizing) contains high concentrations of surfactants as well as readily biodegradable compounds like starch and other carbohydrates . Decyl sulfate (DS, surfactant) and soluble starch were used as model pollutants for biodegradation batch experiments . Very high loadings of the biomass were applied (DS: 21.7-217 g/kg cell dry weight (CDW); starch: 910 g/kg cell dry weight) to study inhibitory effects of the surfactant on the degradation cascade of the biopolymer . The starch hydrolysis was inhibited above sludge loadings of 65 g DS/kg CDW . Acidogenesis was the degradation step with the highest resistance towards inhibitory effects of the surfactant, whereas methanogenesis proved to be the most sensitive . The effects of the surfactant were described by the change of the methane evolution, which was reduced by 50% in 87 days with an addition of 58 g DS/kg CDW . The surfactant caused a high temporary accumulation of intermediates like volatile fatty acids . At the highest loading (217 g DS/kg CDW) the conversion of the substrate to methane was only minor. Environ Monit Assess, 2002 Apr, 75(2), 155 - 67 Transport, deposition and biodegradation of particle bound polycyclic aromatic hydrocarbons in a tidal basin of an industrial watershed; Pohlman JW et al.; Polycylic aromatic hydrocarbons (PAHs) are common contaminants in industrial watersheds . Their origin, transport and fate are important to scientists, environmental managers and citizens . The Philadelphia Naval Reserve Basin (RB) is a small semi-enclosed embayment near the confluence of the Schuylkill and Delaware Rivers in Pennsylvania (USA) . We conducted a study at this site to determine the tidal flux of particles and particle-bound contaminants associated with the RB . Particle traps were placed at the mouth and inside the RB and in the Schuylkill and Delaware Rivers . There was net particle deposition into the RB, which was determined for three seasons . Spring and fall depositions were highest (1740 and 1230 kg of particles, respectively) while winter deposition was insignificant . PAH concentrations on settling particles indicated a net deposition of 12.7 g PAH in fall and 2.1 g PAH in spring over one tidal cycle . There was no significant PAH deposition in the winter . Biodegradation rates, calculated from 14C-labeled PAH substrate mineralization, could attenuate only about 0.25% of the PAH deposited during a tidal cycle in fall . However, in the spring, biodegradation could be responsible for degrading 50% of the settling PAHs . The RB appears to be a sink for PAHs in this watershed. J Biomed Mater Res, 2002 Jul, 61(1), 138 - 45 Mechanical and morphological study of biostable polyurethane heart valve leaflets explanted from sheep; Bernacca GM et al.; Two novel biostable polyurethanes, designated EV3.34 and EV3.35, were used to manufacture a flexible trileaflet heart valve . The valves were implanted in the mitral position in young adult (18 month) sheep . Six valves were electively explanted at 6 months and the remaining six valves at 9 months follow-up . The leaflet material was examined by surface Fourier transform infrared spectrometry (ATR/FTIR) and scanning electron microscopy (SEM) . The leaflet material was also subjected to cyclic mechanical testing and, compared with unimplanted control material, to demonstrate any change in mechanical properties during implantation . There was no degradation of functional groups detected by ATR/FTIR, although there was a slight surface enrichment of siloxane soft segment . Surface morphology of the explanted leaflet material was similar to unimplanted control material . EV3.34 demonstrated similar inelastic energy loss behavior, with no significant change in residual strain in explanted compared with control material . EV3.35 demonstrated a reduction in inelastic energy and residual strain in explanted compared with control material . There is no evidence of biodegradation of these siloxane-based polyurethanes, in functional valves up to 9 months implantation in sheep . The FTIR and SEM findings are supported by the retention of mechanical properties of the materials . J Biomed Mater Res, 2002 Jul, 61(1), 53 - 60 Liquid photocurable biodegradable copolymers: in vivo degradation of photocured poly(epsilon-caprolactone-co-trimethylene carbonate); Mizutani M et al.; Liquid photoreactive poly(epsilon-caprolactone-co-trimethylene carbonate)s endcapped with a coumarin group {coumarinated poly(CL/TMC)s} were prepared using tetra-functional hydroxylated substances such as pentaerythritol or four-branched poly(ethylene glycol), b-PEG . These coumarinated copolymers are tetra-branched and exist as a viscous liquid (MW 5 x10(3) approximately 7 x 10(3)) . They were photocured by ultraviolet (UV) light irradiation to obtain a swelling or nonswelling solid under water, depending on the type of initiator used . The resultant films were implanted into the subcutaneous tissues of rats for up to 5 months . The photocured b-PEG-based copolymer was completely degraded and sorbed within a 1 month . On the other hand, surface-eroding degradation of pentaerythritol-based, coumarinated poly(CL/TMC) progressed with implantation time, and minimal recruitment of neutrophils, macrophages, and multinucleated giant cells was observed over the implantation period . Among the pentaerythritol-based copolymers, the fastest surface erosion was observed for the copolymer with the highest epsilon-caprolactone content . Microfabricated films with microarrays in which photoconstructs were stereolithographically prepared, using three different coumarinated copolymers at different regions, showed that upon implantation there was regionally differentiated biodegradation of microarrays, and the degree of region-specific biodegradation depended on the type of photocured copolymer . The observed tendency for biodegradation was in good agreement with that observed during implantation of individual films in vivo . This study also demonstrates that the use of multi-material-arrayed films enables the determination of different responses in vivo using only one sample . J Contam Hydrol, 2002 Mar, 55(1-2), 57 - 85 Bioenhancement of NAPL pool dissolution: experimental evaluation; Seagren EA et al.; Experiments were conducted to quantify nonaqueous phase liquid (NAPL) pool dissolution and its enhancement by in situ biodegradation . The experiments were performed using square cross-section, glass-bead packed column reactors with a small pool of a toluene-in-dodecane mixture (toluene mole fraction, X(tol) approximately 0.02 or 0.09) . Experimental quasi-steady-state toluene dissolution fluxes were determined using a 14C-carbon mass-balance approach during water flushing with and without biodegradation . The experiments demonstrated a statistically significant bioenhancement of the toluene dissolution flux of up to roughly twofold at average pore water velocities of approximately 0.1 and 1 m/day when the toluene mole fraction was low ( approximately 0.02); however, little or no bioenhancement was observed with the higher mole fraction ( approximately 0.09) . Although it cannot be determined conclusively, the weight of evidence based on biomass measurements and model analyses suggests that the reduced bioenhancement for the high mole fraction was due to higher dissolved toluene concentrations, which may have caused toxicity effects . Importantly, even though NAPL dissolution was not bioenhanced in every case, the biodegradation reduced toluene concentrations to low levels in the reactor effluents. Chemosphere, 2002 Feb, 46(7), 1011 - 7 Butanol extraction to predict bioavailability of PAHs in soil; Liste HH et al.; The feasibility of a mild-solvent extraction procedure to predict the bioavailability of individual polycyclic aromatic hydrocarbons (PAHs) in soil was assessed . The quantities that were degraded during the course of biodegradation of phenanthrene and pyrene in soil with or without plants correlated with the amounts extracted by n-butanol, with R2 values of 0.971 and 0.994, respectively . Six consecutive groups of earthworms removed ca . 70% of the pyrene remaining after extensive biodegradation, a value similar to the quantity extracted by n-butanol . The amount of chrysene aged in sterilized soil that was extracted by n-butanol was not statistically different from the quantities assimilated by earth-worms (Eisenia fetida) introduced into the soil . Such a mild extraction procedure may be useful as a means of predicting PAH bioavailability. Environ Pollut, 2002, 118(1), 65 - 73 Induction of PAH-catabolism in mushroom compost and its use in the biodegradation of soil-associated phenanthrene; Reid BJ et al.; This paper describes the induction of phenanthrene-catabolism within Phase II mushroom compost resulting from its incubation with (1) phenanthrene, and (2) PAH-contaminated soil . Respirometers measuring mineralization of freshly added 14C-9-phenanthere were used to evaluate induction of phenanthrene-catabolism . Where pure phenanthrene (spiked at a concentration of 400 mg kg(-1) wet wt.) was used to induce phenanthrene-catabolism in compost, induction was measurable, with maximal mineralization observed after 7 weeks phenanthrene-compost contact time . Where PAH-contaminated soil was used to induce phenanthrene-catabolism in un-induced compost, induction was observed after 5 weeks soil-compost contact time . Microcosm-scale amelioration of soil contaminated with 14C-phenanthrene (aged in soil for 516 days prior to incubation with compost) indicated that both induced (using pure phenanthrene) and uninduced Phase II mushroom composts were equally able to promote degradation of this soil-associated contaminant . After 111 days incubation time, 42.7 +/- 6.3% loss of soil-associated phenanthrene was observed in the induced-compost soil mixture, while 36.7 +/- 2.9% loss of soil-associated phenanthrene was observed in the uninduced-compost soil mixture . These results are notable as they indicate that while pre-induction of phenanthrene-catabolism within compost is possible, it does not significantly increase the extent of degradation when the compost is used to ameliorate phenanthrene-contaminated soil . Thus, compost could be used directly in the amelioration of contaminated land i.e . without pre-induction of catabolism. Water Res, 2002 Mar, 36(6), 1620 - 8 Development of a kinetic basis for bioavailability of sorbed naphthalene in soil slurries; Park JH et al.; The degradation of naphthalene in soil-slurry systems was studied using four different organisms and two soils . Organisms with zero-order, first-order, and Michaelis-Menten rates were selected . The soils had substantially different sorption distribution coefficients . Sorption and desorption was evaluated in abiotic soil-slurry systems . The desorption process was described by a model that accounts for equilibrium, rate-limited and non-desorbing sites . Biodegradation parameters were measured in soil-extract solutions . Bioavailability assays, inoculated soil slurries, were conducted and both liquid- and sorbed-phase naphthalene concentrations were measured over time . For the less sorptive soil, the results could be explained by sequential desorption and degradation processes . For the other soil, enhanced degradation was clearly observed for the organisms with first-order and Michaelis-Menten rates . Several explanations are explored for these observations including direct sorbed-phase degradation and the development of elevated substrate concentrations at the organism/sorbent interface . No enhancement was found for the organism with zero-order kinetics. Chemosphere, 2002 Apr, 47(3), 303 - 9 Influence of surfactants on solubilization and fungal degradation of fluorene; Garon D et al.; Eighteen fungal strains were tested in toxicity assays with surfactants in order to select surfactants and strains tolerant to surfactants for degradation assays . Two nonionic surfactants were used, an alkylphenol ethoxylate, Triton X-100, a sorbitan ester, Tween 80 and an anionic surfactant, sodium dodecyl sulfate . Solubilization and biodegradation tests were conducted in liquid medium batch; fluorene was quantified by HPLC . Results showed the enhancement of fluorene solubilization by the three surfactants, good tolerance of nonionic surfactants by the fungal strains and the enhancement of the biodegradation of fluorene by Doratomyces stemonitis (46-62%) and Penicillium chrysogenum (28-61%) in the presence of Tween 80 (0.324 mM) after 2 days. Chemosphere, 2002 Apr, 47(1), 9 - 14 Changes in mutagenicity during biodegradation of fenitrothion; Matsushita T et al.; In order to investigate changes in the mutagenicity of fenitrothion during its biodegradation in solution, measurements were conducted at intervals in batch cultures incubated under anaerobic or aerobic conditions . Fenitrothion-degrading bacteria were obtained from a green onion field on the west side of Gifu University, Japan . Fenitrothion was almost completely decomposed by day 12 under both types of incubation condition . The indirect mutagenicity of the solution to strains YG1029 and YG1042, however, increased markedly during anaerobic biodegradation . The increase in mutagenicity was partially due to amino-fenitrothion, a metabolite formed during anaerobic biodegradation of fenitrothion. Kyobu Geka, 2002 May, 55(5), 368 - 73 {First successful clinical application of tissue engineered blood vessel}; Hibino N et al.; With this tissue engineering (TE) technique, the peripheral pulmonary artery was successfully reconstructed, using the patient's own venous cells in a 4-year-old girl, 2 years after Fontan procedure . A 4-year-old girl was given a diagnosis of single right ventricle, double-outlet right ventricle and pulmonary atresia . She underwent left modified Blalock-Taussig shunt at a month old, pulmonary artery angioplasty at a year and 3 months old, and bidirectional cavopulmonary shunt at 2 years and a month old . She underwent again pulmonary artery angioplasty and Fontan operation at 3 years and 3 months . An angiographical examination 7 months after the operation revealed total occlusion of the right intermediate pulmonary artery . TE technique using autologous cells was indicated . The application of this procedure was approved by the ethical committee in Tokyo Women's Medical University . The patient's parents were thoroughly informed and signed a consent form . Approximately 2 cm of the peripheral vein was explanted under sterile conditions . The tissue was minced, placed in tissue culture dishes and cultured at 37 degrees C, 100% humidity and a 5% CO2 atmosphere for almost a month . The number of cells substantially increased to reach 12 millions for almost a month . The culture medium was changed every 3 days . The polymer tube that served as a scaffold for cells was composed of the copolymer of PCL-PLA (50:50) with reinforcement by woven PGA . The polymer conduit, 10 mm in diameter, 20 mm in length and 1 mm in thickness, was designated to biodegradate within 8 weeks . The number of seeded cells was approximately a million/cm2 . The graft transplantation was performed 10 days after seeding cells . The occlusive right intermediate pulmonary artery was reconstructed with the TE vessel graft under extracorporeal circulation with a pump-oxygenator . The patient followed a satisfactory postoperative course . The postoperative angiography demonstrated that the graft was not constricted and dilated but that it preserved good patency . Long-term follow-up are necessary . We plan to continue to use the TE technique using autologous cells in the low pressure system like venous or pulmonary circulation . Because our results even in early experimental phase were valuable and promising, we believe that the TE approach may play an important role in the near future as an another alternative, together with transplantation and artificial organ, especially in the field of cardiovascular surgery that mostly needs replants. Environ Sci Technol, 2002 Apr 15, 36(8), 1676 - 80 Endocrine disrupting nonylphenols are ubiquitous in food; Guenther K et al.; 4-Nonylphenols (NPs) are common products of biodegradation of a widely used group of nonionic surfactants, the nonylphenol ethoxylates (NPEs) . These compounds are known to be persistent, toxic, and estrogen active . There is a worldwide scientific and public discussion on the potential consequences of human long term dietary exposure to such endocrine disrupters . Despite numerous determinations of NPs in environmental samples no systematical reports exist relating to concentrations of NPs in food . We analyzed NPs in 60 different foodstuff commercially available in Germany . The results indicate that NPs are ubiquitous in food . The concentrations of NPs on a fresh weight basis varied between 0.1 and 19.4 microg/kg regardless of the fat content of the foodstuff . Based on data on German food consumption rates and these first analyses of NPs in food, the daily intake for an adult was calculated to be 7.5 microg/day NPs . For infants exclusively fed with breast milk or infant formulas daily intakes of 0.2 microg/day and 1.4 microg/day NPs, respectively, can be estimated. Ann Chim, 2002 Jan-Feb, 92(1-2), 27 - 40 Aerobic biotransformation of linear alkylbenzene sulphonates under laboratory conditions; Marcomini A et al.; Sulphophenyl carboxylates (SPC) derived from the biodegradation of commercial blends of linear alkylbenzene sulphonates (LAS), were recorded during OECD-301E screening tests under aerobic conditions . Both HPLC-FL and GC-MS were employed to determine biotransformation products . Two well defined groups of detectable SPC were generated: transient compounds, i.e . SPC which degrade very quickly, and compounds more persistent than the parent LAS which required an acclimatization period before their mineralization could take place . The biodegradation of a C10-C13 LAS commercial mixture and of two individual homologs (C11-LAS and C12-LAS) led to the identification of the most persistent SPC which were C6-SPC, C7-SPC and C8-SPC . The C6-SPC turned out to be the homolog which biodegrades most slowly, this suggests that odd LAS homologs are more easily biodegradable. Ying Yong Sheng Tai Xue Bao, 2002 Feb, 13(2), 145 - 50 {Accumulation and biodegradation of anthracene by Chlorella protothecoides under different trophic conditions}; Yan X et al.; The bioaccumulation and degradation of anthracene by the green alage(Chlorella prothecoides) under autotrophic and heterotrophic conditions were studied . About 29% and 20% of anthracene(original concentration 1.0 mg.L-1) were degraded by light and by Chlorella protothecoides under the autotrophic condition, respectively . About 33.53% of anthracene (original concentration 2.5 mg.L-1) were degraded by C . protothecoides under the heterotrophic condition . The resistance and degradation ability of C . protothecoides under the heterotrophic condition was higher than that under the autotrophic conditions . More than 80% of residual anthracene was accumulated by algal cell under the two conditions . The bioaccumulation factor were 9064 and 1899, under the autotrophic and heterotropnic conditions, respectively . The net accumulation of anthracene, however, was much higher under the heterotropnic condition (202.29 micrograms) than that under the autotrophic condition (69.687 micrograms). Biotechnol Bioeng, 2002 Jun 20, 78(6), 708 - 13 Kinetic analysis of high-concentration isopropanol biodegradation by a solvent-tolerant mixed microbial culture; Bustard MT et al.; The ability of a previously enriched microbial population to utilize isopropanol (IPA) as the sole carbon source within a minimal salts medium is studied . The advantage of prior enrichment procedures for the improvement of IPA biodegradation performance is demonstrated for an IPA concentration of up to 24 g L(-1) . Results showing the interrelationship between temperature and substrate utilization and inhibition levels at temperatures of between 2 degrees C and 45 degrees C are examined . Models of inhibition based on enzyme kinetics are assessed via nonlinear analysis, in order to accurately represent the growth kinetics of this solvent-tolerant mixed culture . The model that best describes the data is the Levenspiel substrate inhibition model, which can predict the maximum substrate level above which growth is completely limited . This is the first report of IPA treatment of up to 24 g L(-1) by an aerobic solvent-tolerant population . Biotechnol Bioeng, 2002 Jun 20, 78(6), 606 - 16 A kinetic model for surfactant inhibition of pentachlorophenol biodegradation; Cort TL et al.; A kinetic model is used to describe the effect of the nonionic surfactant Tergitol NP-10 (TNP10) on pentachlorophenol (PCP) biodegradation by Sphingomonas chlorophenolica sp . strain RA2 . Different initial biomass to initial substrate ratios ranging from 13 to 418 were tested with 23 TNP10 concentrations ranging from 0 to 1500 mg/L . Tests were also conducted at 10 degrees C and 20 degrees C . No PCP biodegradation inhibition was observed at concentrations below the critical micelle concentration (CMC) of 50 mg/L . TNP10 concentrations above 100 to 200 mg/L were increasingly inhibitory to PCP biodegradation rates . This inhibition was best described by the Monod kinetic equation wherein the effect of TNP10 inhibition is reflected in the half-saturation constant (Ks) . The value of the Ks increased from between 1.5 and 13.5 mg/L with no surfactant present to 44 to 131 mg/L at 1000 mg/L TNP10 . Using a standard competitive inhibition approach, the inhibition constant for TNP10 was approximately 100 mg/L at both 10 degrees C and 20 degrees C . Sci Total Environ, 2002 Apr 15, 288(3), 215 - 26 Occurrence and distribution of linear alkylbenzene sulfonates and sulfophenylcarboxylic acids in several Iberian littoral ecosystems; Leon VM et al.; The distribution of linear alkylbenzene sulfonates (LAS) and sulfophenylcarboxylic acids (SPC) has been characterized in water and sediment of five Iberian estuaries and a saltmarsh channel . The highest concentrations of LAS and SPC were detected in shallow zones close to discharge points of untreated urban effluent, and decreased sharply with increasing distance from these . SPC homologues of between 3 and 12 carbon atoms were detected, although their concentrations were several orders of magnitude lower than the corresponding LAS . The highest SPC concentrations found were of medium carboxylic chain lengths (C6-C8) in water, and of longer chain lengths (C9-C11) in particulate material . LAS homologues were associated preferentially with the particulate material . The vertical distribution of LAS in the water column was not homogeneous, in contrast to that presented by the SPC homologues . In the case of the Sancti Petri Channel, there was a net flow of LAS exportation into the Bay of Cadiz, of -38.6 kg day(-1), and a net flow for SPC of -6.0 kg day(-1) . The daily mass input of LAS and their biodegradation intermediates from the Sancti Petri Channel to Cadiz Bay was 44.6 kg. Mar Environ Res, 2002 May, 53(4), 403 - 15 Seasonal factors affecting surfactant biodegradation in Antarctic coastal waters: comparison of a polluted and pristine site; George AL; This report is the first seasonal study of anthropogenic pollutant biodegradation rates in Antarctic coastal waters . The capacity of surface waters from Rothera Research Station, Adelaide Island, Antarctica, to biodegrade the anionic surfactant sodium dodecyl sulphate (SDS) was quantified in biodegradation tests from April 1988 to January 1999 . Large temporal differences in the persistence of SDS were observed . In mid-winter (July), the SDS-biodegradation half life was twice that measured in mid-summer (January), despite small temperature differences (up to 2.45 degrees C) . Comparisons between water from a pristine site and a site receiving grey-waste water from the station showed that some acclimation to SDS was occurring in the contaminated water . This resulted in SDS half lives up to to approximately 80 h shorter in the polluted water compared with the pristine site in the summer months when a large population of SDS-degrading bacteria had developed . Biodegradation half lives in Antarctic coastal waters (160-460 h) were generally far higher than those observed in temperate waters. Can J Microbiol, 2002 Mar, 48(3), 200 - 3 Biotransformation of waste lignin products by the soil-inhabiting yeast Trichosporon pullulans; Slavikova E et al.; In this study the biotransformation of lignin by-products of beechwood pulping with a soil-inhabiting yeast strain of Trichosporon pullulans was examined . The structural and molecular changes in the lignin during a cultivation process were determined by 13C NMR spectroscopy and gel permeation chromatography analysis, which confirmed the ability of the yeast strain tested to biodegrade lignin . Enzymatic analysis showed the presence of lignin peroxidase and Mn(II) peroxidase in the culture supernatant . The ligninolytic activity of both enzymes increased under carbon-depleted conditions . This observation is particularly important in the biodegradation of recalcitrant lignins in soil. Huan Jing Ke Xue, 2002 Jan 30, 23(1), 70 - 3 {Biodegradation of lignin in wheat straw by alkaliphilic ligninolytic bacteria with compounded carbons}; Zhang J et al.; The article researched enzymes production, the degradation rate of lignin and strain growth of alkaliphilic ligninolytic bacteria strain No . 6 in alkaline liquid medium (pH approximately 10.5) with compounded carbons . The results showed that the highest activities of laccase and MnP were 2915.37 U/L (4th d) and 1152.88 U/L (8th d), respectively, and the strain degraded 49.84% lignin of wheat straw during ten days cultivation . The changes of ultrastructure of wheat straw caused by strain No . 6 attack were investigated with SEM (scan electron microscopy). Food Chem Toxicol, 2002 Jun, 40(6), 767 - 79 Organochlorine chemicals in seafood: occurrence and health concerns; Smith AG et al.; The cheap availability of chlorine gas, together with the development of industrial chlorinating procedures in the 20th century, led to the production of a wide range of organochlorine compounds many with a variety of commercial applications, including usage as insecticides and defoliants and polychlorinated biphenyls (PCBs) used as coolants in electricity supply transformers . However, it was soon found that many of these technologically valuable chemicals suffered from a major disadvantage in that they resisted biodegradation and that the continued use of these compounds would lead to their persistence and accumulation in the environment and thus enter the human food chain . Despite regulatory bans or strict limits on usage being imposed on organochlorine pesticides in most countries, these compounds continue to be detected in measurable amounts in the eco-system including marine life . In general, organochlorine levels in fish intended for human consumption are low and probably below levels likely to adversely affect human health . Populations at higher risk than most people are those subsisting largely on fish and other marine life . Additionally, fish oils obtained from contaminated fish, if consumed in substantial quantities by infants and young children, might present potential health problems if levels are not continually regulated . Behavioral and neurological effects have been reported in children and ascribed to the consumption of PCB contaminated diet including fish . Another current major human health concern, yet to be resolved, about organochlorine contaminants in the human diet relates to the potential ability of many of these chemicals at low doses to act as "endocrine disruptors". Zhonghua Zheng Xing Wai Ke Za Zhi, 2002 Jan, 18(1), 38 - 40 {The experimental study of bioabsorbable mini-plate for rigid fixation on rabbits}; Zhang Z et al.; OBJECTIVE: To study the biodegradation process of the bioabsorbable mini-plate (LactoSorb) and its influence on bone healing . METHODS: 15 mature New Zealand White Rabbits were selected as the experimental animals . The bilateral zygomatic arch were fractured using a fissure bur . One side was fixed with the bioabsorbable mini-plate and the other side was fixed with Titanium mini-plate as a control . 5 animals were killed after 4, 12, and 24 weeks post operation respectively for radiographic and histologic study . RESULTS: At 4 weeks, the absorbable plate changed from transparent to opaque and its dimensions was enlarged . The bone gaps of both groups were filled with new bone . No inflammatory cells were found in both groups . At 12 weeks, the absorbable plate broke to small pieces or particles, its dimensions reduced greatly but the outline could still been recognized . The bone continuity had been reestablished in both groups . At 24 weeks, the absorbable plate was resorbed completely . Only the residual screw could be seen in the screw hole . Complete bone healing was seen in both groups . No histological differences of bone healing were found at this stage . CONCLUSION: The absorbable plate demonstrates excellent biocompatibility . No adverse local inflammatory reactions were found during the plate was absorbed gradually . In the non-weight baring area, the absorbable plate provides the same fixation stability as that of the metal plate. Pest Manag Sci, 2002 Mar, 58(3), 303 - 12 Effect of cropping cycles and repeated herbicide applications on the degradation of diclofop-methyl, bentazone, diuron, isoproturon and pendimethalin in soil; Piutti S et al.; A greenhouse study was conducted to investigate the ability of four crops (wheat, corn, oilseed rape and soybean) to influence the degradation of bentazone, diclofop-methyl, diuron, isoproturon and pendimethalin in soil . The present study showed that microbial biomass-carbon was significantly higher in planted soils than in bulk soil, especially with wheat and corn, after several cropping cycles . The biomass in corn and soybean planted soils was adversely affected by bentazone but recovered after three cropping cycles . In wheat-planted soils, diclofop-methyl application resulted in persistent increase of the amount of microbial biomass . Bentazone did not show accelerated degradation even after five successive treatments, differing from diclofop-methyl, for which two applications were sufficient to enhance significantly its rate of degradation . Enhanced degradation of diclofop-methyl was even more pronounced in wheat-planted soil . The rates of mineralisation of diuron, isoproturon and pendimethalin were not affected after the first cropping cycle, but were significantly increased in planted soils after five cropping cycles . The results confirm that plants may promote pesticide degradation in soil by stimulating biodegradation processes . In the case of diclofop-methyl, stimulation of accelerated degradation was observed. Appl Biochem Biotechnol, 2001 Spring, 91-93, 213 - 7 Biodegradation of formaldehyde by a formaldehyde-resistant bacterium isolated from seawater; Yamazaki T et al.; A formaldehyde-tolerant bacterium designated as a DM-2 strain was used to biodegrade formaldehyde . The cells, precultivated in the presence of 400 ppm of formaldehyde, were able to degrade formaldehyde in a minimal medium supplemented with up to 400 ppm of formaldehyde in the presence of 3% NaCl . The rate of formaldehyde degradation achieved in this study was 45 ppm/h when the DM-2 culture's optical density at 660 nm was 1.2. Bioorg Med Chem Lett, 2002 Mar 25, 12(6), 899 - 902 QSAR study on adenosine kinase inhibition of pyrrolo{2,3-d}pyrimidine nucleoside analogues using the hansch approach; Srikanth K et al.; QSAR studies on series of pyrrolo{2,3-d}pyrimidine nucleoside analogues were performed for their adenosine kinase (AK) inhibitory activity using the Hansch approach . Significant correlations were obtained with hydrophobic parameter at position 'X' . Electronic and steric parameters on pyrimidine and pyrrole rings found to play an important role in the ligand-receptor interactions with the active sites of the enzyme . Presence of bulkier groups at 'X' and 'Y' positions seems to protect the title compounds from biodegradation, as is evident from their positive sterimol steric parameter B1 at these positions. J Agric Food Chem, 2002 Apr 24, 50(9), 2537 - 42 Biodegradation of viticulture wastes by Pleurotus: a source of microbial and human food and its potential use in animal feeding; Sanchez A et al.; The bioconversion of vineyard pruning and grape pomace by Pleurotus spp . using a solid state fermentation (SSF) was evaluated . Fruiting body production and chemical changes in the substrates after harvesting were measured . Biological efficiency and bioconversion ranged from 37.2 to 78.7% and from 16.7 to 38.8%, respectively . The best substrates for mycelial growth and mushroom yield were the mixtures with higher vineyard pruning content . Inclusion of pruning content had higher phenolic components and total sugars, better C/N ratio, and lower crude fat and total nitrogen than pomace . On the contrary, mycelium grew more slowly and scarcely in all treatments with 100% grape pomace . Moisture, protein, fat, and lignin contents were generally higher in mixtures with higher pomace proportion, whereas neutral detergent fiber, hemicellulose, and cellulose contents were higher with pruning content . Pleurotus strains may act depending on the availability of fiber fractions of substrate, and dynamic changes in digestion might occur as these fractions change during fungal growth . The recycling of viticulture residues through SSF by Pleurotus has great potential to produce human food and yields an available high-fiber feed for limited use in ruminants. Int J Oral Maxillofac Implants, 2002 Mar-Apr, 17(2), 161 - 74 Evaluation of a tissue-engineered membrane-cell construct for guided bone regeneration; Schantz JT et al.; PURPOSE: Currently, a number of bioresorbable and biodegradable membranes used for guided bone regeneration lead to incomplete tissue regeneration . Poor mechanical properties, short degradation time, and the lack of integrated biologic components result in the inability to create and maintain an appropriate environment and to actively support tissue remodeling . In the present study, the osteogenic potential of human calvarial periosteal cells in combination with ultrathin polycaprolactone (pc2) membranes of a slow biodegradation rate was investigated . MATERIALS AND METHODS: In vitro and in vivo analyses of the tissue-engineered constructs were conducted using imaging techniques, immunohistochemistry, and histology . Two types of membranes were investigated . Group 1 consisted of a plain membrane, and in group 2 membranes were treated with sodium hydroxide . RESULTS: In vitro results showed that osteoblast-like cells attached and proliferated on the membranes with the formation of extracellular matrix . Sodium hydroxide-treated membranes showed enhanced cell attachment and proliferation kinetics, resulting in a dense cellular layer after 2 weeks in culture . In vivo mineralized tissue formation in association with vascularization was observed . Extracellular matrix calcification with nodule formation was detected via histology as well as scanning electron microscopy . DISCUSSION: PCL membranes support the attachment, growth, and osteogenic differentiation of human primary osteoblast-like cells . Sodium hydroxide-treated membranes demonstrated increased cell attachment resulting from increased hydrophilicity . CONCLUSION: These findings have potential application in the development of a new generation of osteoconductive membranes. Biochemistry, 2002 Apr 23, 41(16), 5185 - 92 X-ray crystal structure of Escherichia coli taurine/alpha-ketoglutarate dioxygenase complexed to ferrous iron and substrates; Elkins JM et al.; Taurine/alpha-ketoglutarate dioxygenase (TauD), a non-heme Fe(II) oxygenase, catalyses the conversion of taurine (2-aminoethanesulfonate) to sulfite and aminoacetaldehyde concurrent with the conversion of alpha-ketoglutarate (alphaKG) to succinate and CO(2) . The enzyme allows Escherichia coli to use taurine, widely available in the environment, as an alternative sulfur source . Here we describe the X-ray crystal structure of TauD complexed to Fe(II) and both substrates, alphaKG and taurine . The tertiary structure and fold of TauD are similar to those observed in other enzymes from the broad family of Fe(II)/alphaKG-dependent oxygenases, with closest structural similarity to clavaminate synthase . Using the TauD coordinates, a model was determined for the closely related enzyme 2,4-dichlorophenoxyacetate/alphaKG dioxygenase (TfdA), supporting predictions derived from site-directed mutagenesis and other studies of that biodegradative protein . The TauD structure and TfdA model define the metal ligands and the positions of nearby aromatic residues that undergo post-translational modifications involving self-hydroxylation reactions . The substrate binding residues of TauD were identified and those of TfdA predicted . These results, along with sequence alignment information, reveal how TauD selects a tetrahedral substrate anion in preference to the planar carboxylate selected by TfdA, providing insight into the mechanism of enzyme catalysis. Waste Manag Res, 2001 Oct, 19(5), 436 - 41 The influence of hydraulic residence time on the treatment of cattle manure in UASB reactors; Maranon E et al.; Cattle manure from farms in the autonomous community of Asturias, Spain, was characterised and subsequently treated, after filtration through a 1 mm sieve, in upflow anaerobic sludge blanket laboratory reactors . The volume generated per cow and day varied between 50-55 litres (obtained through a survey of 400 farms), the manure being used on Asturian farms up until now as a fertiliser . After screening, the COD of the manure employed varied between 33,000 and 56,000 mgO2 l(-1) . The highest percentage of COD removal obtained was 75.5% for a hydraulic residence time of 22.5 days . Gas production varied between values of 0.20-0.39 m3gas kg(-1) COD removed, with a methane content of up to 64% . There was a fraction refractory to biodegradation of 11%. Biochemistry (Mosc), 2002 Feb, 67(2), 184 - 95 Phosphonates and their degradation by microorganisms; Kononova SV et al.; Phosphonates are a class of organophosphorus compounds characterized by a chemically stable carbon-to-phosphorus (C-P) bond . Wide occurrence of phosphonates among xenobiotics polluting the environment has aroused interest in pathways and mechanisms of their biodegradation . Only procaryotic microorganisms and the lower eucaryotes are capable of phosphonate biodegradation via several pathways . Destruction of the non-activated C-P bond by the C-P lyase pathway is of fundamental importance, and understanding of the process is a basic problem of biochemistry and physiology of microorganisms . This review offers analysis of available data on phosphonate-degrading microorganisms, degradation pathways, and genetic and physiological regulation of this process. Waste Manag, 2002, 22(3), 269 - 82 Temporal variation of leachate quality from pre-sorted and baled municipal solid waste with high organic and moisture content; El-Fadel M et al.; Landfill leachate characterization is a critical factor in establishing a corresponding effective management strategy or treatment process . However, it is often difficult to forecast leachate quality because of a variety of influencing factors such as waste composition and landfill operations . This paper describes leachate formation mechanisms, summarizes leachate quality indicators, and investigates the temporal variation of leachate quality from pre-sorted and baled municipal solid waste characterized with high organic and moisture content . The purpose of the study is to evaluate the potential effects of waste composition and site-specific operational procedures on biodegradation processes and leachate quality at a field-scale landfill that receives in excess of 1800 tonnes per day of refuse . For this purpose, waste disposal and leachate generation rates were monitored and leachate samples were collected for a period of 18 months during the early stages of refuse deposition . Chemical analysis was performed on the samples and the temporal variation of several parameters were monitored including pH, COD, TOC, TDS, chlorides, sulfates, orthophosphates, nitrates, ammonia nitrogen, hardness, and heavy metals . Chemical concentration levels were related to biological activity within the landfill and the results indicated that: (1) pre-sorting and baling of the waste did not hinder waste stabilization; and (2) the high organic and moisture contents resulted in an extremely strong leachate, particularly at the onset of biodegradation processes, which can affect the leachate treatment facility. Chemosphere, 2002 Mar, 46(8), 1235 - 45 The estimation of PAH bioavailability in contaminated sediments using hydroxypropyl-beta-cyclodextrin and Triton X-100 extraction techniques; Cuypers C et al.; A study was conducted to investigate whether cyclodextrins and surfactants can be used to predict polycyclic aromatic hydrocarbon (PAH) bioavailability in contaminated sediments . Two sediment samples were extracted with aqueous solutions of hydroxypropyl-beta-cyclodextrin (HPCD) and Triton X-100 . PAH removal during extraction was compared with PAH removal during biodegradation and solid-phase extraction . The latter two methods were used as reference methods to establish which part of the PAHs could be biodegraded and to what extent biodegradation was governed by bioavailability limitations . It was demonstrated that HPCD extraction followed solid-phase extraction and removed primarily readily bioavailable PAHs, while Triton X-100 extracted both readily and poorly bioavailable PAHs . Moreover, HPCD did not affect the degradation of PAHs in biodegradation experiments, while Triton X-100 enhanced the degradation of low molecular weight PAHs . It was concluded that HPCD extraction may provide a good method for the prediction of PAH bioavailability . Triton X-100 extraction is unfit for the prediction of PAH bioavailability. J Biomed Mater Res, 2002 Jun 15, 60(4), 651 - 6 Biodegradation of carbonate apatite/collagen composite membrane and its controlled release of carbonate apatite; Matsumoto T et al.; The aim of this study was to investigate the biodegradation of carbonate apatite (CO(3)Ap)/collagen composite membrane as a new guided tissue regeneration membrane in vivo and to estimate its controlled release of CO(3)Ap in vitro . To control the biodegradation of the guided tissue regeneration membrane and to promote hard tissue regeneration in the periodontal region, we added CO(3)Ap into the collagen membrane . To investigate the biodegradation of CO(3)Ap/collagen composite membranes, the prepared membranes (CO(3)Ap:0, 10 wt %) were cut into 5 x 5 x 0.1 mm and subcutaneously implanted into the backside of male rats under general anesthesia . The explanted membranes were investigated histologically . To estimate their controlled release of CO(3)Ap in vitro, the membranes (CO(3)Ap 0-10 wt %, 5 x 5 x 0.1 mm) were immersed into collagenase solution and compulsorily dissolved for 48 h . Histological results suggested that the membrane had a good biocompatibility and the biodegradable period was shortened with the presence of CO(3)Ap . In the solubility experiments of the membrane, eluted Ca concentrations gradually increased with total dependence on the dissolution of the collagen membrane . Our study demonstrated that the biodegradation time can be controlled by CO(3)Ap contents in the membrane and CO(3)Ap could be released from the membrane with the biodegradation period . Rev Argent Microbiol, 2002 Jan-Mar, 34(1), 39 - 44 {Effect of cocultivating fungal species on the degradation of lignocellulose residues}; Braga EJ et al.; The degradation potential of Phanerochaete sordida, Trametes trogii, Coprinus truncorum and Paecilomyces sp . upon yard wastes was evaluated . The species had been inoculated individually or in pairs formed by P . sordida and Paecilomyces sp., T . trogii and Paecilomyces sp., and C . truncorum and Paecilomyces sp . The highest level of endoxilanase activity was produced by P . sordida growing alone, during day 21 (1.09 U/g of dry material), but in P . sordida and Paecilomyces sp . cultures, the detected activity did not overcome 0.27 U/g of dry material during the whole experiment . T . trogii showed maximum activity on day 14 (0.78 U/g of dry material), but in T . trogii and Paecilomyces sp . cultures, the values increased until day 21 (1.07 U/g of dry material) . P . sordida endocellulase activity reached its maximum on day 28 (0.08 U/g of dry material), but in P . sordida and Paecilomyces sp . cultures, this activity increased during the whole experiment (0.04 U/g of dry material) . The major weight loss was found in P . sordida (27.6%) . The possible beneficial effect of co-culture in yard wastes biodegradation is discussed. Polim Med, 2001, 31(3-4), 52 - 60 The preliminary evaluation of HAP + TCP composite material biodegradation after implantation in muscular tissue of rats; Domagala Z et al.; Ceramic biomaterials based on calcium phosphates have a special position among modern implantation material in osteosurgery . Non-reabsorbable hydroxyapatite (HAP) and reabsorbable tricalcium phosphate are the most popular calcium phosphate ceramics . The appropriate ratio of these two compounds should result in forming the gradually reabsorbable implants, overgrowing with the bone tissue which mechanical strength should not be negatively affected . The aim of this work was to evaluate a local tissue reaction and the HAP + TCP composite resorption rate as compared with HAP, after implantation in a muscle tissue of rats . On the basis of carried macroscopic and microscopic evaluations, it can be stated that the new HAP + TCP composite had high biocompatibility and were gradually reabsorbed . This enables faster overgrowing the implant with tissue. Appl Microbiol Biotechnol, 2002 Mar, 58(3), 409 - 15 Epub 2001 Dec 21. Natural attenuation potential of cyanide via microbial activity in mine tailings; Oudjehani K et al.; Biological removal by indigenous microflora of cyanide, contained in old (6-9 years) and fresh tailings (3 months), was studied in order to assess its natural attenuation potential via biodegradation . To investigate the presence of indigenous microflora in tailings, total heterotrophic and cyanide resistant bacteria were counted using the spread-plate method . The free cyanide mineralization potential was estimated using K14CN in the presence of various unlabeled cyanide concentrations (0, 5, and 10 mg CN/kg) . The biodegradation of cyanide contained initially in the samples was also investigated by monitoring formate, formamide, ammonia and total cyanide (CNT) concentrations over 111 days . The enumeration of total heterotrophic and cyanide-resistant bacteria in old tailings showed an average population of 105 cfu/g . However, no growth was detected in fresh tailings . Nevertheless, cyanide mineralization tests indicated the presence, in both old and fresh tailings, of a cyanide-degrading microflora . In old tailings, maximum mineralization percentages of free cyanide ranging from 85% to 100% were obtained after 65 days at all concentrations tested . A mineralization percentage of 83% after 170 days was also observed in fresh tailings . No decrease of total cyanide concentration in old tailings was observed when the biodegradation of endogenous cyanide was tested whereas a significant decrease was recorded in fresh tailings after 96 days . The presence of strong metal-cyanide complexes resistant to biodegradation could explain the absence of biodegradation in old tailings . This study demonstrated the presence of an indigenous free cyanide-degrading microflora in both old and fresh tailings, and suggests that natural attenuation of cyanide in gold mine tailings is likely to occur via microbial activity. Ann Pharm Fr, 2001 Nov, 59(6), 366 - 8 {Effect of cyclodextrins on fungal degradation of fluorene}; Garon D et al.; The purpose of this study was to improve the bioavailability of fluorene (PAH) by the use of complexing agents, cyclodextrins . The biodegradation tests were performed in liquid medium batches; fluorene was quantified by HPLC . Experimental results showed the enhancement of fluorene degradation by Penicillium italicum and Phanerochaete chrysosporium in the presence of branched cyclodextrins. Biomaterials, 2002 Apr, 23(7), 1707 - 19 Interactions between resin monomers and commercial composite resins with human saliva derived esterases; Jaffer F et al.; Cholesterol esterase (CE) and pseudocholinesterase (PCE) have been reported to degrade commercial and model composite resins containing bisphenylglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) or the latter in combination with urethane modified BisGMA monomer systems . In addition, human saliva has been shown to contain esterase like activities similar to CE and PCE . Hence, it was the aim of the current study to determine to what extent human saliva could degrade two common commercial composite resins (Z250 from 3M Inc . and Spectrum TPH from L.D . Caulk) which contain the above monomer systems . Saliva samples from different volunteers were collected, processed, pooled, and freeze-dried . TEGDMA and BisGMA monomers were incubated with human saliva derived esterase activity (HSDEA) and their respective hydrolysis was monitored using high performance liquid chromatography (HPLC) . Both monomers were completely hydrolyzed within 25 h by HSDEA . Photopolymerized composites were incubated with buffer or human saliva (pH 7.0 and 37 C) for 2, 8 and 16 days . The incubation solutions were analyzed using HPLC and mass spectrometry . Surface morphology characterization was carried out using scanning electron microscopy . Upon biodegradation, the Z250 composite yielded higher amounts of BisGMA and TEGDMA related products relative to the TPH composite . However, there were higher amounts of ethoxylated bis-phenol A released from the TPH material . In terms of total mass of products released, human saliva demonstrated a greater ability to degrade Z250 . In summary, HSDEA has been shown to contain esterase activities that can readily catalyze the biodegradation of current commercial composite resins. Appl Environ Microbiol, 2002 Apr, 68(4), 1569 - 75 Comparison of extracellular enzyme activities and community composition of attached and free-living bacteria in porous medium columns; Lehman RM et al.; Free-living and surface-associated microbial communities in sand-packed columns perfused with groundwater were compared by examination of compositional and functional characteristics . The composition of the microbial communities was assessed by bulk DNA extraction, PCR amplification of 16S ribosomal DNA fragments, separation of these fragments by denaturing gradient gel electrophoresis, and sequence analysis . Community function was assessed by measurement of beta-glucosidase and aminopeptidase extracellular enzyme activities . Free-living populations in the aqueous phase exhibited a greater diversity of phylotypes than populations associated with the solid phase . The attached bacterial community displayed significantly greater beta-glucosidase and aminopeptidase enzyme activities per volume of porous medium than those of the free-living community . On a per-cell basis, the attached community had a significantly higher cell-specific aminopeptidase enzyme activity (1.07 x 10(-7) nmol cell(-1) h(-1)) than the free-living community (5.02 x 10(-8) nmol cell(-1) h(-1)) . Conversely, the free-living community had a significantly higher cell-specific beta-glucosidase activity (1.92 x 10(-6) nmol cell(-1) h(-1)) than the surface-associated community (6.08 x 10(-7) nmol cell(-1) h(-1)) . The compositional and functional differences observed between these two communities may reflect different roles for these distinct but interacting communities in the decomposition of natural organic matter or biodegradation of xenobiotics in aquifers. J Am Chem Soc, 2002 Mar 27, 124(12), 2917 - 23 Influence of silaproline on peptide conformation and bioactivity; Cavelier F et al.; The analogue gamma-(dimethylsila)-proline, denoted silaproline (Sip), was synthesized in both enantiomerically pure forms by diastereoselective alkylation of a chiral glycine equivalent with use of Schollkopf's bis-lactim ether method . The effect of replacing a proline residue in model peptides by this new proline surrogate has been examined in the crystal state by X-ray diffraction and in solution by IR absorption and NMR techniques . Silaproline and proline-containing sequences exhibit very similar conformational properties . Silaproline was also substituted for proline in a neurotensin (8-13) analogue that retained biological activity and exhibited enhanced resistance to biodegradation. Water Res, 2002 Mar, 36(5), 1253 - 61 Nonionic surfactant effects on pentachlorophenol biodegradation; Cort TL et al.; Several potential mechanisms of surfactant-induced inhibition of pentachlorophenol (PCP) biodegradation were tested using a pure bacterial culture of Sphingomonas chlorophenolicum sp . Strain RA2 . PCP degradation, glucose degradation, and oxygen uptake during endogenous conditions and during glucose degradation were measured for batch systems in the presence of the nonionic surfactant Tergitol NP-10 (TNP10) . TNP10 did not exert toxicity on RA2 as measured by dissolved oxygen uptake rates under endogenous conditions and glucose biodegradation rates . TNPIO reduced the substrate inhibition effect of PCP at high PCP concentrations, resulting in faster PCP degradation rates at higher concentrations of TNP10 . Calculations of a micelle partition coefficient (Kmic) show that PCP degradation rates in the presence of surfactant can be explained by accounting for the amount of PCP available to the cell in the aqueous solution . A model is discussed based on these results where PCP is sequestered into micelles at high TNP10 concentrations to become less available to the bacterial cell and resulting in observed inhibition . Under substrate toxicity conditions, the same mechanism serves to increase the rate of PCP biodegradation by reducing aqueous PCP concentrations to less toxic levels. J Contam Hydrol, 2002 Feb, 54(3-4), 249 - 76 Humic acid enhanced remediation of an emplaced diesel source in groundwater . 1 . Laboratory-based pilot scale test; Van Stempvoort DR et al.; The enhanced solubility of petroleum-derived compounds in humic acid solutions is the basis for a new groundwater remediation technology . In this unique pilot-scale test, a stationary contaminant source consisting of diesel fuel was placed below the water table in a model sand aquifer (1.2 x 5.5 x 1.8-m deep) and flushed with water at a flow rate of 2 cm/h over 5 years . At 51 days, laboratory grade humic acid was added to the water and maintained at a level of approximately 0.8 g/l . The addition of humic acid had only a small impact on the aqueous transport of the BTEX components, which were rapidly dissolved from the diesel, but had a large effect on the flushing of PAHs, including methylated naphthalenes (MNs) . Binding to aqueous humic acid enhanced the solubilization of MNs two- to tenfold . During aqueous transport, biodegradation of the BTEX and PAHs occurred, limiting the lateral and longitudinal extent of the diesel contaminant plume in the model aquifer . It appears that through enhanced solubilization, the overall biodegradation rate of the MNs was increased . As the various MNs were depleted from the diesel source, the MN plume shrank and then disappeared. J Contam Hydrol, 2002 Feb, 54(3-4), 195 - 213 Using polymer mats to biodegrade atrazine in groundwater: laboratory column experiments; Patterson BM et al.; Large-scale column experiments were undertaken to evaluate the potential of in situ polymer mats to deliver oxygen into groundwater to induce biodegradation of the pesticides atrazine, terbutryn and fenamiphos contaminating groundwater in Perth, Western Australia . The polymer mats, composed of woven silicone (dimethylsiloxane) tubes and purged with air, were installed in 2-m-long flow-through soil columns . The polymer mats proved efficient in delivering dissolved oxygen to anaerobic groundwater . Dissolved oxygen concentrations increased from <0.2 mg l(-1) to approximately 4 mg l(-1) . Degradation rates of atrazine in oxygenated groundwater were relatively high with a zero-order rate of 240-380 microg l(-1) or a first-order half-life of 0.35 days . Amendment with an additional carbon source showed no significant improvement in biodegradation rates, suggesting that organic carbon was not limiting biodegradation . Atrazine degradation rates estimated in the column experiments were similar to rates determined in laboratory culture experiments, using pure cultures of atrazine-mineralising bacteria . No significant degradation of terbutryn or fenamiphos was observed under the experimental conditions within the time frames of the study . Results from these experiments indicate that remediation of atrazine in a contaminated aquifer may be achievable by delivery of oxygen using an in situ polymer mat system. Folia Microbiol (Praha), 2001, 46(6), 535 - 9 High-temperature hydrocarbon biodegradation activities in Kuwaiti desert soil samples; Obuekwe CO et al.; Soil samples taken monthly from the Burgan South oil field of Kuwait for one year degraded crude oil, phenanthrene, and hexadecane . Bacteria were better degraders at high-temperature (55 degrees C) than fungi, especially in the drier, hotter months . Depending on the period of sampling, bacteria degraded hydrocarbons in the range of 46-86% (crude oil), 42-100% (hexadecane) and 5-58% (phenanthrene) . Fungi alone accounted for degradation by 20-81% (crude oil), 30-95% (hexadecane) and less than 55% (phenanthrene). J Lipid Res, 2002 Mar, 43(3), 495 - 509 Identification of metabolites from type III F2-isoprostane diastereoisomers by mass spectrometry; Chiabrando C et al.; F(2)-isoprostanes (F(2)-iPs) are prostaglandin (PG)-like products of non-enzymatic free radical-catalyzed peroxidation of arachidonic acid that are now widely used as indices of lipid peroxidation in vivo . Knowledge of the metabolic fate of F(2)-iPs in vivo is still scant, despite its importance for defining their overall formation and biological effects in vivo . Type III F(2)-iPs, which are diastereoisomers of cyclooxygenase-derived PGF(2alpha), may be metabolized through the pathways of PG metabolism . We therefore studied the in vitro metabolism of eight synthetic Type III F(2)-iP diastereoisomers in comparison with PGF(2alpha) . We used gas chromatography-mass spectrometry and high performance liquid chromatography-electrospray-tandem mass spectrometry for structural identification of metabolites formed after incubation of the various compounds with isolated rat hepatocytes . PGF(2alpha) was metabolized to several known products, resulting from a combination of beta-oxidation, reduction of Delta(5) and/or Delta(13) double bonds, and 15-OH oxidation, plus other novel products deriving from conjugation with taurine of PGF(2alpha) and its metabolites . Of the eight F(2)-iP diastereoisomers, some were processed similarly to PGF(2alpha), whereas others showed peculiar metabolic profiles according to specific stereochemical configurations.These data represent the first evidence of biodegradation of selected Type III F(2)-iP isomers other than 8-epi-PGF(2alpha), through known and novel pathways of PGF(2alpha) metabolism . The analytical characterization of these products may serve as a basis for identifying the most significant products formed in vivo. J Environ Sci (China), 2002 Jan, 14(1), 132 - 5 Mechanisms of granular activated carbon anaerobic fluidized-bed process for treating phenols wastewater; Lao SG; Granular activated carbon (GAC) anaerobic fluidized-bed reactor was applied to treating phenols wastewater . When influent phenol concentration was 1000 mg/L, volume loadings of phenol and CODCr were 0.39 kg/(m3.d) and 0.98 kg/(m3.d), their removal rates were 99.9% and 96.4% respectively . From analyzing above results, the main mechanisms of the process are that through fluidizing GAC, its adsorption is combined with biodegradation, both activities are brought into full play, and phenol in wastewater is effectively decomposed . Meanwhile problems concerning gas-liquid separation and medium plugging are well solved. Environ Sci Pollut Res Int, 2002, 9(1), 62 - 72 Sulphonated aromatic pollutants . Limits of microbial degradability and potential of phytoremediation; Schwitzguebel JP et al.; Many synthetic sulphonated aromatic compounds are used as starting material to produce dyes and pigments, or are released as by-products in the effluents of the textile and dye industry . A large number of these chemicals are poorly biodegradable and cannot be eliminated by classical wastewater treatment plants . To limit the impact of these pollutants on the environment, new processes, based on the use of higher plants (constructed wetlands or hydroponic systems), are under development . Detergents and surfactants are essential for both industrial and domestic applications, the most important family being the alkylbenzene sulphonates . Originally, the alkyl side chains were branched and thus recalcitrant to biodegradation . Therefore, they have been replaced by linear alkylbenzene sulphonates . Although more acceptable, present formulations still have adverse environmental and toxic effects . In this context, phytoremediation appears to be a promising approach to remove these compounds from contaminated soils and waters. Environ Toxicol Chem, 2002 Mar, 21(3), 480 - 8 The potential for estradiol and ethinylestradiol degradation in English rivers; Jurgens MD et al.; Water samples were collected in spring, summer, and winter from English rivers in urban/industrial (River Aire and River Calder, Yorkshire, UK) and rural environments (River Thames, Oxfordshire, UK) to study the biodegradation potential of the key steroid estrogen 17beta-estradiol (E2) and its synthetic derivate ethinylestradiol (EE2) . Microorganisms in the river water samples were capable of transforming E2 to estrone (E1) with half-lives of 0.2 to 9 d when incubated at 20 degrees C . The E1 was then further degraded at similar rates . The most rapid biodegradation rates were associated with the downstream summer samples of the River Aire and River Calder . E2 degradation rates were similar for spiking concentrations throughout the range of 20 ng/L to 500 microg/L . Microbial cleavage of the steroid ring system was demonstrated by release of radiolabeled CO2 from the aromatic ring of E2 (position 4) . When E2 was degraded, the loss of estrogenicity, measured by the yeast estrogen screen (YES) assay, closely followed the loss of the parent molecule . Thus, apart from the transient formation of E1, the degradation of E2 does not form other significantly estrogenic intermediates . The E2 could also be degraded when incubated with anaerobic bed sediments . Compared to E2, EE2 was much more resistant to biodegradation, but both E2 and EE2 were susceptible to photodegradation, with half-lives in the order of 10 d under ideal conditions. Environ Toxicol Chem, 2002 Mar, 21(3), 489 - 92 Studies on the effect of soil aging on the toxicity of pyrene and phenanthrene to a soil-dwelling springtail; Sverdrup LE et al.; Soil samples spiked with five concentrations of pyrene and phenanthrene were aged for 0, 10, 40, and 120 d before toxicity was investigated using a standardized bioassay with the soil-dwelling collembolan Folsomia fimetaria L . Toxic effects were measured as reductions in survival and reproductive output after 3 weeks of exposure . Both pyrene and phenanthrene were degraded in the test system during storage, phenanthrene to a higher degree than pyrene . However, when toxic effects of the tested substances were calculated on the basis of measured concentrations of the parent compounds, toxicity was unaffected by storage for up to 120 d . Many studies have shown a negative correlation between aging and the biodegradation of polycyclic aromatic hydrocarbons (PAHs), indicating a reduction in the bioavailability of PAHs to micro-organisms with time . Our results indicate that a reduction in toxicity, as related to the measured concentrations of the parent compounds in the soil, may not always be expected for aged soils . Provided that metabolites of pyrene and phenanthrene did not significantly contribute to the toxicity in aged soil samples, a possible explanation for the absence of aging effects is the high test concentrations used in combination with the low content of organic carbon (1.6%) in the test soil. Appl Microbiol Biotechnol, 2002 Feb, 58(2), 241 - 7 Fungal contribution to in situ biodegradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) film in soil; Sang BI et al.; The contribution of fungi to the microbial degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) films in soil was studied . Various traces, cavities, and grooves observed on the dented surface of PHBV films demonstrated that the degradation was a concerted effect of a microbial consortium colonizing the film surface, including fungi, bacteria, and actinomycetes . The succession of microbial consortia in the soil around the PHBV films during the degradation showed a distinctive increase in the fungal population, resulting in its dominance . Comparison of the degradation ability of microbial strains isolated from soil where PHBV films were degraded, revealed that fungi showed the highest contribution to PHBV degradation, growing very rapidly along the film surface with their high degradation ability and then expanding their hyphae in a three-dimensional manner. J Environ Monit, 2002 Feb, 4(1), 96 - 101 Biological reduction of perchlorate in ion exchange regenerant solutions containing high salinity and ammonium levels; Gingras TM et al.; The most promising technologies to remove perchlorate from water are ion exchange and biological reduction . Although successful, ion exchange only separates perchlorate from water; it does not eliminate it from the environment . The waste streams from these systems contain the caustic or saline regenerant solutions used in the process as well as high levels of perchlorate . Biological reduction could be used to treat the regenerant waste solutions from the ion exchange process . A treatment scheme, combining ion exchange and biodegradation, is proposed to completely remove perchlorate from the environment . Perchlorate-laden resins generate brines containing salt concentrations up to 6% or caustic solutions containing up to 0.5% ammonium . Both, high salt and ammonium hydroxide concentrations are potentially toxic to microorganisms . Therefore, the challenge of the proposed system is to find perchlorate reducing microorganisms that are effective under such stressful conditions . Preliminary results have shown that salt concentrations as low as 0.5% reduced the perchlorate biodegradation rate by 30%; salt concentrations greater than 1% decreased this rate to 40% . Although biodegradation was seen in ammonium levels of 0.4%, 0.6% and 1%, the perchlorate biodegradation rate was 90% of that at 0% ammonium hydroxide . Further research will focus on the isolation and/or acclimation of microorganisms that are able to biodegrade perchlorate under these stressful conditions. Environ Sci Technol, 2002 Feb 1, 36(3), 477 - 83 Particle-scale understanding of the bioavailability of PAHs in sediment; Talley JW et al.; This study reports results of sediment bioslurry treatment and earthworm bioaccumulation for polycyclic aromatic hydrocarbon (PAH) contaminants found in sediment dredged from Milwaukee Harbor . A significant finding was that bioslurry treatment reduced PAHs on the sediment clay/silt fraction but not on the sediment coal-derived fraction and that PAH reduction in the clay/silt fraction correlated with substantial reduction in earthworm PAH bioaccumulation . These findings are used to infer PAH bioavailability from characterization of particle-scale PAH distribution, association, and binding among the principal particle fractions in the sediment . The results are consistent with work showing that the sediment comprised two principal particle classes for PAHs, coal-derived and clay/silt, each having much different PAH levels, release rates, and desorption activation energies . PAH sorption on coal-derived particles is associated with minimal biodegradation, slow release rates, and high desorption activation energies, while PAH sorption on clay/silt particles is associated with significant potential biodegradability, relatively fast release rates, and lower desorption activation energies . These characteristics are attributed to fundamental differences in the organic matter to which the PAHs are sorbed . Although the majority of the PAHs are found preferentially on coal-derived particles, the PAHs on the clay/silt sediment fraction are more mobile and available, and thus potentially of greater concern . This study demonstrates that a suite of tests comprising both bioassays and particle-scale investigations provide a basis to assess larger-scale phenomena of biotreatment of PAH-impacted sediments and bioavailability and potential toxicity of PAH contaminants in sediments . Improved understanding of contaminant bioavailability aids decision-making on the effectiveness of biotreatment of PAH-impacted sediments and the likelihood for possible reuse of dredged sediments as reclaimed soil or fill. Toxicol Lett, 2002 Mar 10, 128(1-3), 215 - 28 Enzymes involved in the detoxification of organophosphorus, carbamate and pyrethroid insecticides through hydrolysis; Sogorb MA et al.; The most employed insecticides for indoor and agriculture purposes belong to carbamates, pyrethroid or organophosphates . The chemical structures of these three groups correspond to carbamic, carboxylic and triphosphoric esters . Technical monographs suggest that the hydrolysis of ester bonds of carbamates and pyrethroids plays an important role in the detoxification of these compounds . However, detailed studies about enzymes hydrolysing carbamates and pyrethroids in vertebrates are not available . Certain carbamate hydrolysing activities are associated to serum albumin . Phosphotriesterases, being of an unknown physiological role, hydrolyse (in some cases stereospecifically) organophosphorus insecticides (OP) . Phosphotriesterases have been found in a multitude of species, from mammals to bacteria . A phosphotriesterase activity, EDTA-resistant, has been detected in serum albumin . Phosphotriesterases in serum of mammals display polymorphisms . Phosphotriesterases offer applications in therapy of organophosphorus poisonings, in biodegradation and bioremedation of organophosphates . Similar studies should be developed with enzymes hydrolysing pyrethroids and carbamate insecticides . Such studies will improve the knowledge of the detoxification routes in non-target species and will help to design specific and safer carbamate and pyrethroid insecticides. Biomacromolecules, 2002 Jan-Feb, 3(1), 201 - 7 Formation of and coalescence from the inclusion complex of a biodegradable block copolymer and alpha-cyclodextrin . 2: A novel way to regulate the biodegradation behavior of biodegradable block copolymers; Shuai X et al.; A biodegradable block copolymer (PCL-b-PLLA, M(n) = 1.72 x 10(4), M(w)/M(n) = 1.37) of poly(epsilon-caprolactone) (PCL) and poly(L-lactide) (PLLA) with very low crystallinity was obtained by forming the inclusion complex between alpha-cyclodextrin molecules and PCL-b-PLLA followed by coalescence of the guest polymer chains . Films of the as-synthesized and coalesced copolymer samples, PCL and PLLA homopolymers of approximately the same chain lengths as the corresponding blocks of PCL-b-PLLA, and a physical blend of PCL/PLLA homopolymers with the same molar composition as PCL-b-PLLA were prepared by melt-compression molding between Teflon plates . Subsequently, the in vitro biodegradation behavior of these films was studied in phosphate buffer solution containing lipase from Rhizopus arrhizus, by means of ultraviolet spectra, attenuated total reflectance FTIR spectra, differential scanning calorimetry, wide-angle X-ray diffraction measurements, and weight loss analysis . PCL segments were found to degrade much faster than PLLA segments, both in the pure state and in copolymer or blend samples . Consistent with our expectation, suppression of the phase separation, as well as a decrease of crystallinity, in the coalesced copolymer sample led to a much faster enzymatic degradation than that of either as-synthesized copolymer or the PCL/PLLA physical blend sample, especially during the early stages of biodegradation . Thus the biodegradation behavior of biodegradable block copolymers, which is of decisive importance in drug delivery and controlled release systems, may be regulated by the novel and convenient means recently reported by us.(1) Biol Pharm Bull, 2002 Feb, 25(2), 268 - 71 Effect of chondroitin sulfate on the biodegradation and drug release of chitosan gel beads in subcutaneous air pouches of mice; Kofuji K et al.; Chitosan (CS) gel beads were prepared in 10% amino acid solution (pH 9) and modified by forming an electrostatic complex between the amino group of CS and the carboxyl group of chondroitin sulfate (Cho) . Modification of the CS gel matrix by Cho inhibited the in vitro release of prednisolone (PS) from the gel beads . CS gel beads modified by Cho (CS-Cho) were implanted into air pouches (AP) prepared subcutaneously on the dorsal surfaces of mice . No inflammatory response was observed . The in vivo release of PS from CS-Cho gel beads and their biodegradation in the AP was slower than beads without Cho treatment . After 28 days of implantation, CS-Cho gel beads (deacetylation of CS: 90%) were still detectable, although they had become softer and smaller . Modification of the CS gel matrix by Cho controls the biodegradation of the beads and the release of the drug . This effect makes these beads a promising biocompatible and biodegradable vehicle for sustained drug delivery. J Appl Microbiol, 2002, 92(1), 22 - 31 Mechanisms for enhanced biodegradation of petroleum hydrocarbons by a microbe-colonized gas-liquid foam; Ripley MB et al.; AIMS: A microbe-colonized gas-liquid foam formulation has been previously shown to provide enhanced biodegradation capabilities in soil microcosms . The present study considers the reservoir properties of this foam and how this affects hydrocarbon degradation rates . METHODS AND RESULTS: Oxygen solubility in protein hydrolysate solutions draining from aerated and oxygenated foams was measured . The suitability of oxygenated foam to enhance the degradation of n-hexadecane in soil microcosms was assessed . Sorption of bacterial isolates at the gas-liquid interface was also investigated using a range of microscopy techniques . CONCLUSIONS: Oxygenated bioactive foam enhanced biodegradation rates by improving oxygen availability and transfer . Biodegradation of n-hexadecane was also stimulated by the protein hydrolysate used and by the inclusion of known bacterial hydrocarbon-degrading bacteria . The interaction of bacteria with the gas-liquid interface was shown to be a significant factor governing the drainage of the bacteria from the bioactive foam . SIGNIFICANCE AND IMPACT OF THE STUDY: Protein hydrolysate-based bioactive foam may be a suitable treatment technology to enhance the biodegradation of petroleum hydrocarbons in soil. Bioresour Technol, 2002 Mar, 82(1), 95 - 7 Effect of natural rubber processing sludge on the degradation of crude oil hydrocarbons in soil; Okieimen CO et al.; Crude oil-polluted soil (five parts of weathered crude oil per 100 parts of soil; equivalent to 50,000 mg oil kg(-1) soil) samples were slurried in deionised water (300% of the water retention capacity of the soil) and treated with various amounts of natural-rubber processing sludge (nitrogen content 62.15 mg kg(-1) and phosphorus contents 8.75 mg kg(-1)) in a well-stirred, continuously-aerated tank at 29 degrees C . Changes in the total hydrocarbon content of the soil sample were determined, using a spectrophotometric technique, as a function of time . The extent of crude oil degradation was markedly higher (by up to 100%) in the sludge-treated soil than in the untreated soil sample . The efficiency of biodegradation of the crude oil hydrocarbons using the slurry-phase technique was compared with that of solid-phase technique. Environ Microbiol, 2001 Nov, 3(11), 720 - 30 Biomonitoring of pJP4-carrying Pseudomonas chlororaphis with Trb protein-specific antisera; Schmidt-Eisenlohr H et al.; The transfer of catabolic genes on conjugative plasmids to indigenous organisms from which they may spread further into the community allows the introduction of new biodegradative pathways for metabolic conversion of pollutants to the community . Biomonitoring of IncP plasmid pJP4-carrying Pseudomonas chlororaphis from the rhizosphere of Arabidopsis thaliana was achieved using antisera specific for proteins from the plasmid transfer machinery . Antisera were generated that recognized TrbC and TrbF, the putative major and minor components of pJP4-determined pili, respectively, and the putative lipoprotein TrbH . Cell fractionation studies showed association of TrbC, TrbF and TrbH with the cells and suggested that TrbC and TrbF are part of extracellular pJP4-determined pili . TrbF and TrbH antisera allowed specific detection of IncP compared with IncN or IncW plasmid-carrying cells and even permitted differentiation between bacteria carrying IncPalpha plasmid RP4 and IncPbeta plasmid pJP4 . Immunofluorescence microscopy was applied to detect TrbF and TrbH signal at the cell periphery, allowing distinction from autofluorescing cells and soil debris . In situ experiments showed specific recognition of pJP4-carrying cells from laboratory cultures, as well as from the rhizosphere of A . thaliana grown in natural soil . After co-inoculation of donor P . chlororaphis pJP4 and recipient Ralstonia eutropha, a combination of immunofluorescence and oligonucleotide hybridization techniques permitted the detection of plasmid transfer between both organisms in the A . thaliana rhizosphere . This strategy may be generally applicable for the analysis of plasmid transfer in natural ecosystems. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002 Jan, 37(1), 29 - 41 Biodegradation of polyvinyl alcohol by Phanerochaete chrysosporium after pretreatment with Fenton's reagent; Huang MH et al.; Polyvinyl alcohol (PVA) solutions (BP05 and BF17; 5.0%, wt v(-1)) were degraded by a combination of chemical (Fenton's reagent) and fungal (Phanerochaete chrysosporium) treatments . The overall degradations of BP05 and BF17 were 74.4 and 72.8%, respectively, as determined by chemical oxygen demand (COD) analysis, and 63.7% and 57.7%, respectively, as determined by total organic carbon (TOC) analysis . Increased retention times and changes in the intensity of the PVA peaks on gel permeation chromatograms indicated that PVA molecules of greater molecular weights were degraded to lower molecular weights by both the chemical and fungal treatments . The predominant enzyme secreted by P . chrysosporium in medium containing 2% (wt v(-1)) ground cereal bran in 60 mM phosphate buffer (pH 6.0) was manganese peroxidase . Neither laccase nor lignin peroxidase activity was detected . Manganese peroxidase was probably involved in the biodegradation of the PVA solutions. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002 Jan, 37(1), 113 - 25 A multimedia fugacity river model of pentachlorophenol in South Drainage Canal, China; Chi J et al.; An investigation of Pentachlorophenol (PCP) in South Drainage Canal and Haihe Estuary, Tianjin, China was carried out from 1998 to 1999 . PCP was found in each sample of the surface microlayer, subsurface water, sediment and air . The waste drainage from a PCP-producing plant was the main pollution source of PCP to Haihe Estuary . The enrichment phenomenon of PCP in the surface microlayer was reported for the first time . The maximum enrichment factor was 4.11 . A multimedia (including air, the surface microlayer, water and sediment) fugacity river model was established and successfully applied to fate data for pentachlorophenol in South Drainage Canal . The results showed that under steady state, 97.09% of the loaded PCP was removed by advective outflow into Bohai Bay and 2.46% was by the biodegradation in the water phase . The residue of PCP in South Drainage Canal mainly distributed (99.56%) in the water phase . The discharge rate of PCP from South Drainage Canal to Bohai Bay was 53.4 kg/h. J Environ Qual, 2002 Jan-Feb, 31(1), 144 - 9 Impact of methylene chloride on microorganisms and phenanthrene mineralization in soil; Schwartz E et al.; This study investigated the effects of the quantity of methylene chloride, used as a carrier solvent for phenanthrene when added to soil, on phenanthrene mineralization kinetics, soil phospholipid fatty add profiles (PLFA), and phenanthrene distribution . Methylene chloride dosages of 25 microL/g soil or more resulted in an enrichment of saturated PLFAs, suggesting soil microorganisms had adjusted their cell membranes in response to the solvent . A greater fraction of phenanthrene mineralized when spiked in 5 microL/g than in 25 microL/g methylene chloride suggesting that the methylene chloride became toxic to phenanthrene-degrading organisms in soil . Phenanthrene was more equally distributed among 0.1 g soil subsamples if spiked in 25 than 5 or 1 microL methylene chloride per gram soil . Thus the amount of methylene chloride used to spike phenanthrene in soil strongly impacted the mineralization kinetics, phenanthrene distribution, and microbial community in soil . Because a variety of spiking methods are used in biodegradation research, scientists should consider the quantity of solvents used when comparing results among different studies. Appl Microbiol Biotechnol, 2002 Jan, 58(1), 39 - 45 Biodegradation of atrazine and related s-triazine compounds: from enzymes to field studies; Wackett LP et al.; s-Triazine ring compounds are common industrial chemicals: pesticides, resin intermediates, dyes, and explosives . The fate of these compounds in the environment is directly correlated with the ability of microbes to metabolize them . Microbes metabolize melamine and the triazine herbicides such as atrazine via enzyme-catalyzed hydrolysis reactions . Hydrolytic removal of substituents on the s-triazine ring is catalyzed by enzymes from the amidohydrolase superfamily and yields cyanuric acid as an intermediate . Cyanuric acid is hydrolytically processed to yield 3 mol each of ammonia and carbon dioxide . In those cases studied, the genes underlying the hydrolytic reactions are localized to large catabolic plasmids . One such plasmid, pADP-1 from Pseudomonas sp . ADP, has been completely sequenced and contains the genes for atrazine catabolism . Insertion sequence elements play a role in constructing different atrazine catabolic plasmids in different bacteria . Atrazine chlorohydrolase has been purified to homogeneity from two sources . Recombinant Escherichia coli strains expressing atrazine chlorohydrolase have been constructed and chemically cross-linked to generate catalytic particles used for atrazine remediation in soil . The method was used for cleaning up a spill of 1,000 pounds of atrazine to attain a level of herbicide acceptable to regulatory agencies. Chemosphere, 2002 Jan, 46(3), 477 - 84 PCB removal from contaminated dredged material; Tang NH et al.; The purpose of this study was to evaluate the feasibility of decontaminating PCB contaminated sediment using land treatment technology . Five glass aquariums were set up to test the disappearance of polychlorinated biphenyls (PCBs) in dredged sediment under laboratory conditions that simulated photodegradation, biological transformation, and volatilization in dredged material confined disposal facilities (CDFs) . A 40% decline in PCB concentration was achieved over a period of 5 months . Analysis of the variance in the data showed that periodic tilling produced a tangible effect on the disappearance of PCBs . However, the process or processes responsible for PCB disappearance could not be determined . PCB disappearance from the sediment was most likely caused by a combination of photolysis, volatilization, and biodegradation mechanisms rather than by any single process. Water Res, 2002 Feb, 36(3), 667 - 75 Simultaneous adsorption and biodegradation processes in sequencing batch reactor (SBR) for treating copper and cadmium-containing wastewater; Lim PE et al.; The application of simultaneous adsorption and biodegradation processes in the same reactor is known to be effective in the removal of both biodegradable and non-biodegradable contaminants in various kinds of wastewater . The objective of this study is to evaluate the efficacy of the two processes under sequencing batch reactor (SBR) operation in treating copper and cadmium-containing synthetic wastewater with powdered activated carbon (PAC) as the adsorbent . The SBR systems were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in the ratio of 0.5: 3.5: 1.0: 0.75 :0.25 for a cycle time of 6 h . In the presence of 10 mg/L Cu(II) and 30 mg/L Cd(II), respectively, the average COD removal efficiencies were above 85% with the PAC dosage in the influent solution at 143 mg/L compared to around 60% without PAC addition . Copper(II) was found to exert a more pronounced inhibitory effect on the bioactivity of the microorganisms compared to Cd(II) . It was observed that the combined presence of Cu(II) and Cd(II) did not exert synergistic effects on the microorganisms . Kinetic study conducted for the REACT period showed that the addition of PAC had minimized the inhibitory effect of the heavy metals on the bioactivity of microorganisms. Water Res, 2002 Feb, 36(3), 633 - 7 A method for treating wastewater containing formaldehyde; Lotfy HR et al.; Many industrial activities utilise formaldehyde as a key chemical in organic synthesis including: synthesis of special chemicals such as pentaerythritol and ethylene glycol, synthetic resins, paper products, medicinal products and drugs and others, too numerous to mention . Therefore, effluents arising from these applications may contain significant amounts of formaldehyde . In a biodegradation experiments of a wastewater sample containing formaldehyde ranging from 31.5 to 125 mg/l, residual formalin (a solution of formaldehyde gas in water) ranging from 40% to 85%, respectively, was found at the end of the run (16 d) showing the inhibition effect of formalin which increased with the increase in formalin concentration . The biodegradation of formalin decreased significantly at concentrations higher than 300 mg/l . A method to convert formaldehyde to an easily biodegradable substance is herein described . In the commercial manufacture of resins from phenol and formalin the reaction is never completely quantitative . As a result during the dehydration stage phenol and formalin are distilled from the wastewater . Phenol is toxic to several biochemical reactions . However, biological transformation of phenol to a non-toxic entity is possible through specialized microbes . Transformation of phenol is inhibited by the presence of formaldehyde . Biotransformation of phenol in a wastewater containing high concentrations of formaldehyde started shortly after treating the wastewater with calculated amounts of sodium sulphite . Sodium sulphite is believed to react with formaldehyde forming sodium formaldehyde bisulphite, which is not only non-toxic to microorganisms but also a biodegradable substance . From the DO measurements before and after the addition of sodium sulphite, the authors noticed that the dissolved oxygen in a wastewater containing formaldehyde is not affected by the addition of the calculated amount of sodium sulphite, which is just enough to consume the measured amount of for