J Clin Microbiol, 2005 Jan, 43(1), 476 - 8 Activities of available and investigational antifungal agents against rhodotorula species; Diekema DJ et al.; Rhodotorula species are emerging pathogens in immunocompromised patients . We report the in vitro activities of eight antifungals against 64 Rhodotorula isolates collected in surveillance programs between 1987 and 2003 . Rhodotorula strains are resistant in vitro to fluconazole (MIC at which 50% of the isolates tested are inhibited {MIC(50)}, >128 microg/ml) and caspofungin (MIC(50), >8 microg/ml) . Amphotericin B (MIC(50),1 microg/ml) and flucytosine (MIC(50), 0.12 microg/ml) are both active in vitro, and the new and investigational triazoles all have some in vitro activity, with ravuconazole being the most active (MIC(50), 0.25 microg/ml). Tree Physiol, 2005 Mar, 25(3), 289 - 97 Seasonal variations in location and population structure of endophytes in buds of Scots pine; Pirttila AM et al.; We studied the location and distribution of a bacterial isolate, a Mycobacterium sp., in buds of Scots pine (Pinus sylvestris L.) . Using a probe specific for the 16S rRNA of the Mycobacterium sp., the bacterium was found by in situ hybridization in the meristematic tissues of 40% of all bud samples examined . Because we had previously found other bacterial and fungal endophytes in the meristematic tissues of Scots pine buds, we studied their occurrence in buds during shoot development and dormancy . Using probes targeted to the 16S or 18S rRNA of the endophytes Mycobacterium sp., Methylobacterium spp., Pseudomonas spp . and Rhodotorula minuta, endophytes were found in association with growing tissues, with Methylobacterium spp . being the dominant species . Endophytes were detected in abundance before elongation or differentiation of a bud, but once a tissue was fully developed, endophytes were no longer detected . Metabolic activity of the endophytes was suppressed at the onset of, and during, dormancy of Scots pine, but recovered before the following growing season. Huan Jing Ke Xue, 2004 Sep, 25(5), 153 - 7 {Isolation of heterotrophic microorganism and its role in bioleaching of heavy metals from tannery sludge}; Wang SM et al.; A heterotrophic microorganism was isolated from sewage sludge, it was identified as Rhodotorula sp . R30 . Its optimum pH for growth was 3-7, but it can stand the acidity of pH 2.5-1.5 . The optimum temperature was 28 degrees C . When R30 was inoculated in the medium containing dissolved organic matter derived from sewage sludge and incubated for 96 h, dissolved organic carbon in the medium declined from 1485 mg/L to 345 mg/L, and the yeast number was 4.8 x 10(7) mL(-1) . It was found through the batch trial that the period of bioleaching could be apparently shorted to 4 days if R30 was inoculated in the bioleaching system . Furthermore, the removal efficiency of Cr in sewage sludge could be enhanced by 39% with compared to the control without inoculating R30. Pesqui Odontol Bras, 2004 Jul-Sep, 18(3), 197 - 201 Prevalence of yeasts in the oral cavity of children treated with inhaled corticosteroids; Komiyama EY et al.; The aim of this study was to observe the prevalence of Candida spp . in the oral cavity of children undergoing treatment with inhaled corticosteroids . Thirty children treated with inhaled corticosteroids and thirty control children were studied . Saliva samples were collected through oral rinses with phosphate buffered saline (PBS) . The samples were plated on Sabouraud's dextrose agar and incubated at 37 degrees C for 48 h . After this period, the number of colony-forming units per ml (cfu/ml) of saliva was calculated . The isolates were identified by phenotypic characterization . Candida spp . was isolated from 43.33% of the samples of children treated with corticosteroids, with a mean of 780 cfu/ml of saliva, and from 30% of the samples of the control group, with a mean of 560 cfu/ml of saliva . No significant statistical difference was observed between the groups . C . albicans was the prevalent species in both groups, followed by C . guilliermondii, C . parapsilosis and C . stellatoidea . Furthermore, Rhodotorula rubra and C . lusitaniae were also isolated from the treated group . We concluded that there was no significant increase in the prevalence and number of Candida spp . in the oral cavity of children treated with inhaled corticosteroids. J Am Chem Soc, 2004 Nov 24, 126(46), 15081 - 6 Direct chemical synthesis of the beta-mannans: linear and block syntheses of the alternating beta-(1-->3)-beta-(1-->4)-mannan common to Rhodotorula glutinis, Rhodotorula mucilaginosa, and Leptospira biflexa; Crich D et al.; Two stereocontrolled syntheses of a methyl glycoside of an alternating beta-(1-->4)-beta-(1-->3)-mannohexaose, representative of the mannan from Rhodotorula glutinis, Rhodotorula mucilaginosa, and Leptospira biflexa, are described . Both syntheses employ a combination of 4,6-O-benzylidene- and 4,6-O-p-methoxybenzylidene acetal-protected donors to achieve stereocontrolled formation of the beta-mannoside linkage . The first synthesis is a linear one and proceeds with a high degree of stereocontrol throughout and an overall yield of 1.9% . The second synthesis, a block synthesis, makes use of the coupling of two trisaccharides, resulting in a shorter sequence and an overall yield of 4.4%, despite the poor selectivity in the key step. Rev Iberoam Micol, 2004 Jun, 21(2), 90 - 2 {Carbohydrate assimilation by clinical and environmental Rhodotorula glutinis strains}; Garcia-Martos P et al.; This study was carried to determine the carbohydrate assimilation patterns of Rhodotorula strains isolated from clinical and environmental specimens . We have tested the commercial system ID 32C (bioMerieux, France) on 80 different strains of Rhodotorula glutinis: 47 strains from clinical samples and 33 strains from environmental samples . The assimilation percentages obtained in our study for galactose, cellobiose, gluconate and sorbose were lower than those showed in the identification table of the method . However, the assimilation percentages for mannitol and esculin were higher . According to our results, we conclude that the numerical profiles and the identification software of the commercial system present limitations for the characterization of some R . glutinis strains. J Antibiot (Tokyo), 2004 Aug, 57(8), 511 - 7 Growth inhibition dependent on reactive oxygen species generated by C9-UK-2A, a derivative of the antifungal antibiotic UK-2A, in Saccharomyces cerevisiae; Fujita K et al.; UK-2A is a potent antifungal antibiotic and its structure is highly similar to that of antimycin A3 (AA) . UK-2A and AA inhibit mitochondrial electron transport at complex III . C9-UK-2A, which has been prepared to improve the duration of the antifungal activity of UK-2A, shows durable fungicidal activities against various species of fungi and induces both membrane injury and the generation of cellular reactive oxygen species (ROS) against Rhodotorula mucilaginosa IFO 0001 cells . We found that C9-UK-2A inhibited the vegetative growth of Saccharomyces cerevisiae IFO 0203 cells accompanying cellular ROS generation in Sabouraud dextrose (SD) medium, which contained a fermentable carbon source . The ROS generation was completely restricted by pretreatment with a lipophilic antioxidant alpha-tocopherol . In addition, the pretreatment with the antioxidant protected against the growth inhibition induced by C9-UK-2A . C9-UK-2A also induced ROS generation in isolated mitochondria of the S . cerevisiae cells . The addition of both a complex I inhibitor rotenone and a complex II inhibitor thenoyltrifluoroacetone reduced ROS generation induced by C9-UK-2A in the whole cells and the isolated mitochondria . The addition of the inhibitors of complex III, AA or myxothiazol, or of complex IV, KCN, did not reduce ROS generation . These results suggest that C9-UK-2A induces ROS generation due to the blockade of electron flow at complex III, thereby inhibiting the growth of S . cerevisiae in SD medium. Allergy Asthma Proc, 2004 Jul-Aug, 25(4), 219 - 23 Mold-induced hypersensitivity pneumonitis; Greenberger PA; Mold-induced hypersensitivity pneumonitis results from macrophage- and lymphocyte-driven inflammation, which may be attributable to contaminated humidifiers or heating-ventilation systems or sources in homes, schools, or workplaces . A case may be suspected when there is water intrusion or inadequate drainage . Some fungal causes include species of Alternaria, Aspergillus, Cryptostroma, Penicillium, Pullularia, Rhodotorula, and Trichosporon . The differential diagnosis includes mold-induced asthma, sick building syndrome, mass psychogenic illness (epidemic hysteria), unjustified fears of "toxic" molds, and conditions causing recurrent pneumonitis. DNA Seq, 2004 Jun, 15(3), 202 - 5 Cloning and sequencing of an epoxide hydrolase gene from Rhodosporidium paludigenum; Labuschagne M et al.; Epoxide hydrolase (EH) activity was recently described in yeasts and highly selective hydrolysis of epoxides was observed during whole cell biotransformations . To expand the available molecular data regarding yeast EHs, the EH encoding gene from Rhodosporidium paludigenum (CBS 6565) was isolated, cloned and sequenced . The genomic EH sequence revealed a 1600 bp sequence interrupted by six introns . cDNA sequence analysis revealed an open reading frame of 1236 bp with a deduced polypeptide length of 411 amino acids . The deduced amino acid sequence revealed a relative high degree of sequence homology compared to the amino acid sequence of the EH from Rhodotorula glutinis. Yeast, 2004 Oct 15, 21(13), 1077 - 81 Mycosporine-glutaminol-glucoside, a UV-absorbing compound of two Rhodotorula yeast species; Sommaruga R et al.; High-performance liquid chromatography (HPLC), alone or in combination with mass spectrometry (MS), was used to screen the basidiomycetous yeasts Rhodotorula minuta and R . slooffiae isolated from lakes for the presence of UV-absorbing compounds . Mycosporine-glutaminol-glucoside (maximum absorption, 310 nm), a UV-photoprotective mycosporine known in terrestrial fungi, was the major UV-absorbing compound found in these species . This is the first identification of a mycosporine in yeasts . The presence of this compound seems to be a promising chemotaxonomical marker for yeast systematics . Copyright (c) 2004 John Wiley & Sons, Ltd. Ecotoxicol Environ Saf, 2005 Jan, 60(1), 87 - 100 Assessment of anthracene toxicity toward environmental eukaryotic microorganisms: Tetrahymena pyriformis and selected micromycetes; Bonnet JL et al.; The toxicity of anthracene, a nonmutagenic, noncarcinogenic, low-molecular-weight polycyclic aromatic hydrocarbon present in the environment, was assessed using a ciliated protozoan, Tetrahymena pyriformis, and a selection of 10 micromycetes from different taxonomic groups living in two environmental compartments, namely aquatic and soil ecosystems . With T . pyriformis, a concentration-dependent inhibitory effect was shown on the cell proliferation rate, IC(50) = 33.40+/-4.84 mg/L (kinetic method) . Phagocytosis of nonsoluble anthracene was confirmed by the presence of digestive vacuoles with photon microscopy . In fungi, anthracene did not exhibit a fungicide effect but showed a fungistatic action . Except for Absidia fusca and Cladosporium herbarum, the micromycetes showed a concentration-dependent decrease in growth . From IC(50) values determined by endpoint or kinetic methods, Rhodotorula glutinis and all of the Ascomycotina (except for Penicillium chrysogenum) were the most sensitive species, while Phanerochaete chrysosporium, P . chrysogenum, and the two Deuteromycotina were more resistant to anthracene . Our discussion focuses on the evaluation of toxicity by the two methods used for the calculation of the IC(50) values (endpoint and kinetic), the advantages of studying growth by a kinetic method (the dynamic aspect), and a comparison of toxicity to T . pyriformis and the different micromycetes. Rev Iberoam Micol, 2003 Jun, 20(2), 41 - 5 {Yeast carriage on the hands of Medicine students}; Silva V et al.; The main focus of our study was to determine the prevalence of yeasts on the hands of Medicine students and other students not related to the Health care system . Between July 1999 and July 2000, 253 students of Medicine (163) and Engineering (90) were studied . Medicine students were grouped as basic (71), pre-clinical (62) and clinical (30) . The Engineering's students were divided into three groups according to the years of study . The total yeasts carried on the hands of Medicine's students were 16% . By group the results were 7% for the basic, 19% for the pre-clinical and 30% for the clinical and the prevalence of the two last groups was higher than the first one . The Engineering's students showed 9% prevalence without differences between years of career . The yeast carriage in the clinical group was higher than the equivalent control group (10%) . The species frequently encountered were Rhodotorula mucilaginosa (Rhodotorula rubra) and Candida parapsilosis, with a tendency to a higher species diversity and colony count in the pre-clinical and clinical groups . This finding could explain the high prevalence of candidemia by C . parapsilosis in our hospitals . In summary, yeast carriage, diversity and quantity in Medicine students were related to the time of being in the hospital environment. Prikl Biokhim Mikrobiol, 2004 Jul-Aug, 40(4), 460 - 5 {Carotenoids and fatty acids in red yeasts Sporobolomyces roseus and Rhodotorula glutinis}; Davoli P et al.; Rhodotorula glutinis and Sporobolomyces roseus, grown under different aeration regimes, showed differential responses in their carotenoid content . At higher aeration, the concentration of total carotenoids increased relative to biomass and total fatty acids in R . glutinis, but the composition of carotenoids (torulene > beta-carotene > gamma-carotene > torularhodin) remained unaltered . In contrast, S . roseus responded to enhanced aeration by a shift from the predominant beta-carotene to torulene and torularhodin, indicating a biosynthetic switch at the gamma-carotene branch point of carotenoid biosynthesis . The overall levels of total carotenoids in highly aerated flasks were 0.55 mol-percent and 0.50 mol-percent relative to total fatty acids in R . glutinis and S . roseus (respectively), and 206 and 412 microg g(-1) dry weight (respectively). Biochim Biophys Acta, 2004 Oct 1, 1702(1), 19 - 32 On the mechanism of Rhodotorula gracilis D-amino acid oxidase: role of the active site serine 335; Boselli A et al.; Serine 335 at the active site of D-amino acid oxidase from the yeast Rhodotorula gracilis (RgDAAO) is not conserved in other DAAO sequences . To assess its role in catalysis, it was mutated to Gly, the residue present in mammalian DAAO, an enzyme with a 35-fold lower turnover number with D-alanine . The spectral and ligand binding properties of the S335G mutant are similar to those of wild-type enzyme, suggesting an active site with minimally altered electrostatic properties . The S335G mutant is catalytically active, excluding an essential role of S335 in catalysis . However, S335-OH contributes to the high efficiency of the mutant enzyme since the catalytic activity of the latter is lower due to a decreased rate of flavin reduction relative to wild-type RgDAAO . Catalytic rates are pH-dependent and appear to converge to very low, but finite and similar values at low pH for both wild-type and S335G RgDAAO . While this dependence exhibits two apparent pKs with wild-type RgDAAO, with the S335G mutant a single, apparent pK approximately 8 is observed, which is attributed to the ionization of the alphaNH2 group of the bound substrate . Removal of S335-OH thus suppresses an apparent pK approximately 6 . Both wild-type RgDAAO and the S335G mutant exhibit a substantial deuterium solvent kinetic isotope effect (> or =4) at pH<7 that disappears with increasing pH and reflects a pKapp=6.9 +/- 0.4 . Interestingly, the substitution suppresses the activity towards d-lactate, suggesting a role of the serine 335 in removal of the substrate alpha-OH hydrogen. FEMS Yeast Res, 2004 Sep, 4(8), 857 - 63 Rhodotorula cycloclastica sp . nov., Rhodotorula retinophila sp . nov., and Rhodotorula terpenoidalis sp . nov., three limonene-utilizing yeasts isolated from soil; Nguyen Thanh V et al.; During a search for yeasts that hydroxylate monoterpenes, four yeast strains were isolated from soil and plant residue in monoterpene-rich environments using enrichment techniques with cyclohexanedioic acid or cyclohexanedimethanol as sole carbon source . These strains were able to utilize (+)-limonene supplied as a vapor as only carbon source . The yeasts have a CoQ-10 system . Morphology and physiological properties of the strains did not fit any known yeast species . Recent analysis of the 26S D1/D2 and ITS-5.8S rDNA sequences of basidiomycetous yeasts showed that these strains represented three hitherto unknown species of Rhodotorula and fell in a cluster consisting of Rhodotorula philyla and the mycoparasitic fungus Colacogloea peniophorae . Descriptions of three new species Rhodotorula cycloclastica (type strain TVN 309=UOFS Y 2046=CBS 8448), Rhodotorula retinophila (type strain TVN 295=UOFS Y 2043=CBS 8446), Rhodotorula terpenoidalis (type strain TVN 310=UOFS Y 2042=CBS 8445) are proposed to accommodate these isolates. Mem Inst Oswaldo Cruz, 2004 Jun, 99(4), 425 - 31 Epub 2004 Aug 13. Oral Candida flora from Brazilian human immunodeficiency virus-infected patients in the highly active antiretroviral therapy era; Melo NR et al.; One of the main opportunistic fungal infections amongst immunocompromised individuals is oral candidosis, which has been found in up to 90% of human immunodeficiency virus (HIV)-infected patients . This study employed yeasts isolated from the saliva and oral cavities of 114 HIV-infected patients living in Campinas, Sao Paulo . Of the isolates, 57.8% were identified as Candida albicans and 42.1% as non-C . albicans . The latter isolates were subsequently identified as C . krusei (7.5%), C . lusitaniae (5.2%), C . tropicalis (4.6%), C . parapsilosis (4.6%), C . glabrata (2.8%), C . kefyr (1.7%), C . guilliermondii (1.7%), C . intermedia (1.1%), C . norvegensis (0.5%), and Rhodotorula rubra (1.7%) . Susceptibility of the isolates to amphotericin B, fluconazole, miconazole, and itraconazole was also determined by a microdilution method adopted by the National Committee for Clinical Laboratory Standards . The isolates demonstrated various susceptibilities to the antifungal agents . In particular 29 C . albicans and 13 non-C . albicans isolates showed low susceptibility to FLCZ (> 64 micro g/ml) . This study revealed huge diversity of Candida species, in particular the increasing emergence of non-C . albicans associated with the oral flora of HIV-infected patients. Protein Eng Des Sel, 2004 Jun, 17(6), 517 - 25 Epub 2004 Aug 13. Modulating D-amino acid oxidase substrate specificity: production of an enzyme for analytical determination of all D-amino acids by directed evolution; Sacchi S et al.; Recent research on the flavoenzyme D-amino acid oxidase from Rhodotorula gracilis (RgDAAO) has revealed new, intriguing properties of this catalyst and offers novel biotechnological applications . Among them, the reaction of RgDAAO has been exploited in the analytical determination of the D-amino acid content in biological samples . However, because the enzyme does not oxidize acidic D-amino acids, it cannot be used to detect the total amount of D-amino acids . We now present the results obtained using a random mutagenesis approach to produce RgDAAO mutants with a broader substrate specificity . The libraries of RgDAAO mutants were generated by error-prone PCR, expressed in BL21(DE3)pLysS Escherichia coli cells and screened for their ability to oxidize different substrates by means of an activity assay . Five random mutants that have a 'modified' substrate specificity, more useful for the analytical determination of the entire content of D-amino acids than wild-type RgDAAO, have been isolated . With the only exception of Y223 and G199, none of the effective amino acid substitutions lie in segments predicted to interact directly with the bound substrate . The substitutions appear to cluster on the protein surface: it would not have been possible to predict that these substitutions would enhance DAAO activity . We can only conclude that these substitutions synergistically generate small structural changes that affect the dynamics and/or stability of the protein in a way that enhances substrate binding or subsequently catalytic turnover. Commun Agric Appl Biol Sci, 2003, 68(2 Pt A), 199 - 202 The enhancement of reproduction and biodegradation activity of eukaryiotic cells by humic acids; Siglova M et al.; Fourteen samples of humic acids (HA) were screened for ability to influence reproduction and biodegradation activity of eukaryotic cells in the presence of chosen toxic pollutants . Microorganisms Candida maltosa and Rhodotorula mucilaginosa (soil isolates) were used for all tests . It was observed during our experiments that some samples of humic acids served as a protection against the high concentration of toxic pollutants (phenol, naphtalene etc) . This effect can be widely used in many bioremediation technologies. Biotechnol Lett, 2004 Aug, 26(15), 1197 - 200 Hydrolytic kinetic resolution of the enantiomers of the structural isomers trans -1-phenylpropene oxide and (2,3-epoxypropyl)benzene by yeast epoxide hydrolase; Lotter J et al.; Kinetic resolution of the enantiomers of trans -1-phenylpropene oxide and (2,3-epoxypropyl)benzene was achieved by yeasts from the genus Rhodotorula . The resolution of trans -1-phenylpropene oxide by Rhodotorula glutinis UOFS Y-0123 yielded (1R,2R)-epoxide (ee >98%, yield 30%) and (1R,2S)-diol (ee 95%, yield 40%) . The highest enantio- and regioselectivity toward (2,3-epoxypropyl)benzene resided in Rhodotorula sp . UOFS Y-0448 (E = 6.16), yielding (S)-epoxide (ee 64%, yield 33%) and (R)-diol (ee 67%, yield 28%) . This confirms the superiority of yeasts from the Basidiomycetes genera in the enantioselective hydrolysis of epoxides from different structural classes. Biotechnol Lett, 2004 Aug, 26(15), 1191 - 5 Correlation between the physicochemical properties of organic solvents and their biocompatibility toward epoxide hydrolase activity in whole-cells of a yeast, Rhodotorula sp; Lotter J et al.; Epoxides are often highly hydrophobic substrates and the presence of an organic co-solvent within an aqueous bioreactor is in such cases indicated . The effect of 40 water-miscible and -immiscible organic solvents on epoxide hydrolase activity in whole-cells of the yeast Rhodotorula sp . UOFS Y-0448 was investigated . No formal correlation between solvent biocompatibility and physicochemical properties was deductible, although the introduction of hydroxyl groups increased biocompatibility . 1-Pentanol, 2-methylcyclohexanol and 1-octanol were the most biocompatible resulting in relatively low activity losses when used at up to 20% (v/v). Int J Syst Evol Microbiol, 2004 Jul, 54(Pt 4), 1401 - 7 Curvibasidium cygneicollum gen . nov., sp . nov . and Curvibasidium pallidicorallinum sp . nov., novel taxa in the Microbotryomycetidae (Urediniomycetes), and their relationship with Rhodotorula fujisanensis and Rhodotorula nothofagi; Sampaio JP et al.; Strains of Rhodotorula fujisanensis (Basidiomycota, Urediniomycetes, Microbotryomycetidae), including the type strain, are sexually compatible and produce clamped mycelium with teliospores . However, as teliospore germination had not been documented, the complete sexual cycle was not known . During the course of this work, the basidial stage of R . fujisanensis was characterized . In addition, mating studies employing isolates that were identified preliminarily as Rhodotorula nothofagi, a species that is related closely to R . fujisanensis, yielded mycelium with teliospores, which formed basidia and basidiospores . The new data were evaluated by using several criteria, including the available molecular phylogenetic framework for the Microbotryomycetidae . Curvibasidium gen . nov . is described here, to accommodate two teleomorphs: Curvibasidium cygneicollum sp . nov . (CBS 4551T), which is described as the sexual stage of R . fujisanensis, and Curvibasidium pallidicorallinum sp . nov . (CBS 9091T), which is related closely to R . nothofagi, but does not represent its sexual stage. Biotechnol Lett, 2004 Jul, 26(13), 1087 - 93 LC/MS analysis and lipase modification of the sophorolipids produced by Rhodotorula bogoriensis; Nunez A et al.; The extracellular glycolipids produced by the yeast, Rhodotorula bogoriensis (formerly Candida bogoriensis), were analyzed using an LC/API-MS method . The analysis confirmed that the predominant form the sophorolipid structure contained a C22 hydroxy carboxylic acid . A minor amount (<10%) of a C24 hydroxy carboxylic acid in the sophorolipid was also found, which had not been reported previously . The sophorolipid product, which contained varying degrees of acetylation at the primary hydroxy groups of the sophorose sugar, was deacetylated with sodium methoxide . The des-acetylated sophorolipid was esterified using an immobilized lipase as catalyst in tetrahydrofuran and the product analyzed by mass spectrometric techniques . The product was screened for dimer or polymer formation but only a monomeric lactonized sophorolipid structure was detected. Invest Clin, 2004 Jun, 45(2), 137 - 44 {Assessment of airborne mycoflora in critical areas of the Principal Hospital of Cumaná, state of Sucre, Venezuela}; Centeno S et al.; The study of the nosocomial infections of fungic origin has attained importance in the last years, due to the rise in the number of patients that are inmunocompromised and susceptible to suffer this kind of infection . The objective of the present study was to evaluate the frequency of filamentous fungi and yeast, present in the environment of the Intensive Care Unit, operating and newborn children rooms of the Hospital Universitario "Antonio Patricio de Alcala" (HUAPA) from the city of Cumana . Suere State, Venezuela . The recount of colony forming units/plate (UCF/plate) of the filamentous fungi and yeast was done in Petri plates with Sabouraud dextrose agar, which were exposed in the different studied areas . Eventually, the fungus colonies found were isolated and identified . The area that presented the highest average of UCF/plate was the Intensive Care Unit (9 UCF/plate) . The isolated genus of filamentous fungus in higher proportion were Aspergillus (46.80%), Penicillium (19.19%) and Fusarium (11.06%) . The isolated species with more frequency were Aspergillus niger (24.80%), Aspergillus flavus (10.54%) and Fusarium solani (9.52%) . Rhodotorula glutinis was the isolated yeast with most frequency and different species of the genus Candida and the genus Criptococcus were isolated as well. Mikrobiol Z, 2004 Mar-Apr, 66(2), 92 - 101 {Search of heavy metals biosorbents among yeasts of different taxonomic groups}; Lozovaia OG et al.; The use of microbial cells as heavy metal biosorbents is a potential alternative for the existing methods of the environment treatment for pollution by these metals . Yeast may be successfully used in the metals sorption . An agar-plate screening method was used for rapid isolation of metal-accumulating strains of yeast and preliminary estimation of their biosorption capacity . The capacity to accumulate heavy metals, such as copper, zinc, lead, chrome and cobalt was estimated in 68 pigmented and pigmentless yeast strains isolated from different sources . The best capacity of copper and zinc accumulation was shown by pink-coloured Rhodotorula mucilaginosa, Rhodotorula aurantiaca, Rhodotorula glutinis and pigmentless strains of the yeast Candida krusei, Williopsis california. Physiol Plant, 2004 Jun, 121(2), 305 - 312 Bud endophytes of Scots pine produce adenine derivatives and other compounds that affect morphology and mitigate browning of callus cultures; Pirttila AM et al.; Endophytes are found in meristematic bud tissues of Scots pine (Pinus sylvestris L.) especially prior to growth, which would suggest their involvement in growth of the bud . To test this hypothesis, production of phytohormones by two bacterial (Methylobacterium extorquens, Pseudomonas synxantha) and one fungal endophyte (Rhodotorula minuta) was studied by mass spectrometry . The most common gibberellins, auxins, or cytokinins were not detected in the fractions studied . Instead, M . extorquens and R . minuta produced adenine derivatives that may be used as precursors in cytokinin biosynthesis . A plant tissue culture medium was conditioned with the endophytes, and pine tissue cultures were started on the media . Tetracycline inhibited callus production, which was restored on the endophyte-conditioned media . In addition, conditioning mitigated browning of the Scots pine explants . However, a decrease in tissue size was observed on the endophyte-conditioned media . Addition of adenosine monophosphate in the plant culture medium restored callus production and increased growth of the tissues, but had no effect on browning . Therefore, production of adenine ribosides by endophytes may play some role in the morphological effect observed in the pine tissues. Folia Microbiol (Praha), 2004, 49(1), 19 - 25 Rhodotorula mucilaginosa, a carotenoid producing yeast strain from a Patagonian high-altitude lake; Libkind D et al.; The red yeast Rhodotorula mucilaginosa strain CRUB 0138 (previously identified as R . lactosa) was isolated from a high-altitude Patagonian Lake Toncek (1700 m a.s.l.), and assigned with mucilaginosa species . Its biochemical, physiological and molecular features were assessed and compared to R . mucilaginosa PYCC 5166 type strain using a polyphasic approach; in addition, biomass and carotenoid pigment production at different C/N ratios were determined in an incubator shaker . Phenetic characterization by means of 70 current physiological tests including assimilation of aldaric acids and aromatic compounds, and also the ability to grow with amino acids as sole carbon sources, was carried out . According to numerical taxonomy calculations, similarity indexes between R . mucilaginosa CRUB 0138 and PYCC 5166 type strain were 0.86 and 0.77, corresponding to a complete set of physiological tests and MSP-PCR (Mini/Micro Satellite Primed PCR; (GTG)5, M13 and (GAC)5 primers were employed) fingerprinting . Killer activity against 2 native strains, Rhodosporidium kratochvilovae and R . mucilaginosa was detected . Maximum biomass-glucose conversion efficiency (87%) and maximum carotenoid yield (2.32 mg/L) were obtained at C/N = 5 in culture medium containing 10 and 40 g/L glucose, respectively . Different C/N ratios did not influence carotenoid pigment production but low C/N enhanced biomass yield. J Biol Chem, 2004 Jul 2, 279(27), 28426 - 34 Epub 2004 Apr 21. Unfolding intermediate in the peroxisomal flavoprotein D-amino acid oxidase; Caldinelli L et al.; The flavoenzyme d-amino acid oxidase (DAAO) from Rhodotorula gracilis is a peroxisomal enzyme and a prototypical member of the glutathione reductase family of flavoproteins . DAAO is a stable homodimer with a FAD molecule tightly bound to each 40-kDa subunit . In this work, the urea-induced unfolding of dimeric DAAO was compared with that of a monomeric form of the same protein, a deleted dimerization loop mutant . By using circular dichroism spectroscopy, protein and flavin fluorescence, 1,8-anilinonaphtalene sulfonic acid binding and activity assays, we demonstrated that the urea-induced unfolding of DAAO is a three-state process, yielding an intermediate, and that this process is reversible . The intermediate species lacks the catalytic activity and the characteristic tertiary structure of native DAAO but has significant secondary structure and retains flavin binding . Unfolding of DAAO proceeds through formation of an expanded, partially unfolded inactive intermediate, characterized by low solubility, by increased exposure of hydrophobic surfaces, and by increased sensitivity to trypsin of the beta-strand F5 belonging to the FAD binding domain . The oligomeric state does not modify the inferred folding process . The strand F5 is in contact with the C-terminal alpha-helix containing the Ser-Lys-Leu sequence corresponding to the type 1 peroxisomal targeting signal, and this structural element interacts with the N-terminal betaalphabeta flavin binding motif (Rossmann fold) . The expanded conformation of the folding intermediate (and in particular the higher disorder of the mentioned secondary structure elements) could match the structure of the inactive holoenzyme required for in vivo trafficking of DAAO through the peroxisomal membrane. FEMS Yeast Res, 2004 May, 4(7), 745 - 50 Polyphasic identification of yeasts isolated from bark of cork oak during the manufacturing process of cork stoppers; Villa-Carvajal M et al.; A two-step protocol was used for the identification of 52 yeasts isolated from bark of cork oak at initial stages of the manufacturing process of cork stoppers . The first step in the identification was the separation of the isolates into groups by their physiological properties and RFLPs of the ITS-5.8S rRNA gene . The second step was the sequencing of the D1/D2 domains of the 26S rRNA gene of selected isolates representing the different groups . The results revealed a predominance of basidiomycetous yeasts (11 species), while only two species represented the ascomycetous yeasts . Among the basidiomycetous yeasts, members representing the species Rhodosporidium kratochvilovae and Rhodotorula nothofagi, that have been previously isolated from plant material, were the most abundant . Yeasts pertaining to the species Debaryomyces hansenii var . fabryii, Rhodotorula mucilaginosa and Trichosporon mucoides were isolated in small numbers. Environ Pollut, 1998, 101(2), 303 - 9 Essential interactions between Thiobacillus ferrooxidans and heterotrophic microorganisms during a wastewater sludge bioleaching process; Fournier D et al.; The stimulating effect of heterotrophic microorganisms was investigated on the growth and on the ferrous iron oxidation of Thiobacillus ferrooxidans in synthetic media and in wastewater sludge . The addition of a sediment . Rhodotorula rubra isolate or a strain of T . acidophilus on two-layer agarose-gelled medium doubled the plating efficiency of T . ferrooxidans . In liquid cultures, R . rubra had a slight but significant effect on the growth rate of T . ferrooxidans . Moreover, the yeast allowed a faster initiation of the ferrous iron oxidation and acidification by T . ferrooxidans . In the bioleaching process, the co-culture of T . ferrooxidans with R . rubra or with the indigenous microbial assemblage from sludge was shown to be essential since the pure culture of T . ferrooxidans failed to oxidize ferrous iron and to acidify wastewater sludge . These results emphasize the importance of active heterotrophic microorganisms in the metal bioleaching activity of T . ferrooxidans in sludge. J Infect, 2004 May, 48(4), 339 - 46 Species distribution and influence of glycemic control on fungal infections in pregnant women with diabetes; Nowakowska D et al.; OBJECTIVES: (1) To find the distribution of species among fungal strains isolated from pregnant women with diabetes mellitus (DM), gestational diabetes (GDM) and healthy controls (CON); (2) to analyse the influence of glycemia on the prevalence of fungi in different body sites . METHODS: Mycological examinations were performed in 251 pregnant women: 119 diabetic (47 DM, and 72 GDM) and 132 controls . Samples were collected from vagina, rectum and oral cavity of all women and cultured on Sabouraud media . RESULTS: A total of 212 fungal strains were isolated, 12 fungal species were identified: 89.6% of the strains belonged to Candida gender, 10.4% to Saccharomyces, Geotrichum, Rhodotorula and Trichosporon genera . The prevalence of fungi, respectively, in vagina and rectum, was significantly higher in diabetics with poor glycemic control when stratified (<100 mg/dl, 100-120 mg/dl and >120 mg/dl) both the mean week glucose levels (MWGL) levels (p = 0.03, p = 0.03) and glycemia 90 min after breakfast (p = 0.04, 0.03) . No difference was found in the prevalence of fungi and glycolised hemoglobin (HbA1) . CONCLUSIONS: MWGL showed an association between glycemia and prevalence of fungi . However, no relation was found between HbA1 and fungal infections in well controlled diabetic pregnancies. Biotechnol Prog, 2004 Mar-Apr, 20(2), 467 - 73 Catalytic properties of D-amino acid oxidase in cephalosporin C bioconversion: a comparison between proteins from different sources; Pollegioni L et al.; Lacking an efficient process to produce 7-aminocephalosporanic acid from cephalosporin C in a single step, d-amino acid oxidase (DAAO) is of foremost importance in the industrial, two-step process used for this purpose . We report a detailed study on the catalytic properties of the three available DAAOs, namely, a mammalian DAAO and two others from yeast (Rhodotorula gracilis and Trigonopsis variabilis) . In comparing the kinetic parameters determined for the three DAAOs, with both cephalosporin C and d-alanine as substrate, the catalytic efficiency of the two enzymes from microorganism is at least 2 orders of magnitude higher than that of pig kidney DAAO . Furthermore, the mammalian enzyme is more sensitive to product inhibition (from hydrogen peroxide and glutaryl-7-aminocephalosporanic acid) . Therefore, enzymes from microorganisms appear to be by far more suitable catalysts for bioconversion, although some different minor differences are present between them (e.g., a higher activity of the R . gracilis enzyme when the bioconversion is carried out at saturating oxygen concentration) . The mammalian DAAO, even being a poor catalyst, is more stable with respect to temperature than the R . gracilis enzyme in the free form . In any case, for industrial purposes DAAO is used only in the immobilized form where a strong enzyme stabilization occurs. Biosci Biotechnol Biochem, 2004 Mar, 68(3), 757 - 60 Molecular characterization of a Rhodotorula-lytic enzyme from Paecilomyces lilacinus having beta-1,3-mannanase activity; Sugino H et al.; We cloned the gene and corresponding cDNA for an extracellular Rhodotorula-lytic enzyme which has beta-1,3-mannase activity, tentatively named MAN5C, from Paecilomyces lilacinus . MAN5C showed a high homology score with the members of glycoside hydrolase family 5 in a domain search with the Pfam database, indicating that MAN5C is a novel and unique member of glycoside hydrolase family 5. Trends Biotechnol, 2004 Mar, 22(3), 123 - 9 Fungal epoxide hydrolases: new landmarks in sequence-activity space; Smit MS; Epoxide hydrolases are useful catalysts for the hydrolytic kinetic resolution of epoxides, which are sought after intermediates for the synthesis of enantiopure fine chemicals . The epoxide hydrolases from Aspergillus niger and from the basidiomycetous yeasts Rhodotorula glutinis and Rhodosporidium toruloides have demonstrated potential as versatile, user friendly biocatalysts for organic synthesis . A recombinant A . niger epoxide hydrolase, produced by an overproducing A . niger strain, is already commercially available and recombinant yeast epoxide hydrolases expressed in Escherichia coli have shown excellent results . Within the vast body of activity information on the one hand and gene sequence information on the other hand, the epoxide hydrolases from the Rhodotorula spp . and A . niger stand out because we have sequence information as well as activity information for both the wild-type and recombinant forms of these enzymes. Antonie Van Leeuwenhoek, 2004 May, 85(4), 259 - 69 Alterations in protein synthesis and levels of heat shock 70 proteins in response to salt stress of the halotolerant yeast Rhodotorula mucilaginosa; Lahav R et al.; Responses of the halotolerant yeast Rhodotorula mucilaginosa YRH2 to salt stress was studied . Strain YRH2 was isolated from chemical industry park wastewater evaporation ponds that are characterized by large fluctuations in salinity and pH . Upon shift to high salt medium there is a shutdown of protein synthesis . Radiolabeling and separation of proteins from salt stressed and non-stressed cells identified down-regulated heat shock 70 proteins Ssb1/2p, by N-terminal sequencing and Western blotting . Ssb's role in salt stress in both R . mucilaginosa and S . cerevisiae was examined and we show that its response to salt stress and amino acid limitation is similar . Other proteins such as the heat shock 70 protein Kar2p/BiP and Protein Disulfide Isomerase were strongly induced in response to a shift to high salt in R . mucilaginosa and reacted in a manner similar to the effect of tunicamycin, a known unfolded protein response inducer . Also, assaying carboxypeptidase Y, we showed that high salt medium reduces the specific activity of the enzyme in R . mucilaginosa . It is suggested that the changes in the expression of the heat shock 70 proteins is a part of a mechanism which alleviates the damaging effects of high salt on protein folding in the yeast Rhodotorula mucilaginosa. Int J Food Microbiol, 2004 Mar 15, 91(3), 327 - 35 Potential of using real-time PCR-based detection of spoilage yeast in fruit juice--a preliminary study; Casey GD et al.; A real-time PCR system was used to differentiate between the common spoilage yeasts, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Candida krusei, Rhodotorula glutinis and Saccharomyces cerevisiae, based on melting peak Tm analysis of the 5.8S rDNA subunit and the adjacent ITS2 region of these yeasts . By using the real-time PCR system and by targeting the citrate synthase (cs 1) gene of C . krusei, it was possible to develop a sensitive detection system to both identify and quantitate the level of C . krusei growth in an artificially contaminated apple juice sample. Protein Eng, 2003 Dec, 16(12), 1063 - 9 Dissection of the structural determinants involved in formation of the dimeric form of D-amino acid oxidase from Rhodotorula gracilis: role of the size of the betaF5-betaF6 loop; Piubelli L et al.; The role of the long loop connecting beta-strands F5 and F6 (21 amino acids, Pro302-Leu-Asp-Arg-Thr-Lys-Ser-Pro-Leu-Ser-Leu-Gly-Arg-Gly-Ser-Ala-Arg-Ala-Ala-Lys-Glu322) present in Rhodotorula gracilis d-amino acid oxidase (RgDAAO) was investigated by site-directed mutagenesis . This loop was proposed to play an important role in the 'head-to-tail' monomer-monomer interaction of this dimeric flavoenzyme: in particular, by means of electrostatic interactions between positively charged residues of the betaF5-betaF6 loop of one monomer and negatively charged residues belonging to the alpha-helices I3' and I3" of the other monomer . We produced a mutant of RgDAAO (namely, DAAO-DeltaLOOP2), in which only minor structural perturbations were introduced (only five amino acids were deleted; new sequence of the betaF5-betaF6 loop is Pro302-Leu-Asp-Arg-Thr-Leu-Gly-Arg-Gly-Ser-Ala-Arg-Ala-Ala-Lys-Glu317), and the charge of the betaF5-betaF6 loop not modified . The DeltaLOOP2 mutant is monomeric, has a weaker binding with the FAD cofactor, a decrease of the kinetic efficiency, and slight modifications in its spectral properties . The short version of the loop does not allow a correct monomer-monomer interaction, and its presence in the monomeric DAAO is a destabilizing structural element since the DeltaLOOP2 mutant is highly susceptible to proteolysis . These results, confirming the role of this loop in the subunits interaction and thus in stabilization of the sole dimeric form of RgDAAO, put forward the evidence that even a short deletion of the loop generates a consistent variation of the enzyme structure-function properties. Mar Biotechnol (NY), 2001 Jan, 3(1), 68 - 73 A new isolation method for labyrinthulids using a bacterium, Psychrobacter phenylpyruvicus; Yokochi T et al.; A new isolation method for labyrinthulids, marine microbes with spindle-shaped vegetative cells and gliding movement, is presented . The method for isolating labyrinthulids has been found to be more difficult and less reproducible than that for thraustochytrids, classified in the same order . So far serum seawater agar fortified with antibiotics has been proposed to be the best for isolation of labyrinthulids . The method presented here involves placing plant samples on an agar medium on which a marine bacterium, Psychrobacter phenylpyruvicus, has been grown . The new method, which utilizes fallen mangrove leaves as source material, was more than twice as effective as isolation agar medium without the bacterium . The increased effectiveness appears to derive partly from the bacterial colonies' delaying extension of fungal mycelium . The bacterium was more effective for the isolation of labyrinthulids than either the bacterium Shewanella sp . or the yeast Rhodotorula rubra. Appl Microbiol Biotechnol, 2004 Aug, 65(3), 344 - 8 Epub 2004 Jan 23. Treatment of the yeast Rhodotorula glutinis with AlCl(3) leads to adaptive acquirement of heritable aluminum resistance; Tani A et al.; When aluminum (Al) was added to a culture, growth of Rhodotorula glutinis IFO1125 was temporarily arrested, showing longer lag phases, depending on the Al concentrations (50-300 microM) added, but the growth rates were not affected at all . Resistant strains obtained by one round of plate treatment containing Al reverted the resistance level to the wild-type level when cultivated without Al . Repeated Al treatments, however, induced heritable and stable Al resistance, the level of which was increased up to 4,000 microM by stepwise increments in Al concentrations . Thus, the heritable Al resistance adaptively acquired was due neither to adaptation nor to mutation, but to a mechanism which has yet to be studied . Heritable Al resistance seemed to release the Al inhibition of magnesium uptake. FEMS Yeast Res, 2004 Jan, 4(4-5), 557 - 61 Reinstatement of Rhodotorula colostri (Castelli) Lodder and Rhodotorula crocea Shifrine & Phaff, former synonyms of Rhodotorula aurantiaca (Saito) Lodder; Inacio J et al.; Rhodotorula aurantiaca (Saito) Lodder is an anamorphic basidiomycetous yeast species that belongs to the so-called "Erythrobasidium lineage" of the Urediniomycetes, according to molecular phylogenetic studies based on nucleotide sequence analyses of different ribosomal DNA regions . In the most recent editions of the yeast taxonomy treatises the species Rhodotorula colostri (Castelli) Lodder and Rhodotorula crocea Shifrine & Phaff were listed as synonyms of R . aurantiaca . Taxonomic heterogeneity within R . aurantiaca was demonstrated in a study based on whole-cell protein profiles and is also hinted at by the observed differences in physiological and biochemical characteristics among the different strains under that species name . We determined partial nucleotide sequences of the 26S rRNA gene (D1/D2 domains) of strains maintained in the CBS culture collection under R . aurantiaca, including the type strains of its synonyms . The results showed that R . colostri and R . crocea are clearly distinct from R . aurantiaca and from any other currently recognised basidiomycetous yeast species . Furthermore, phylogenetic analysis of the sequence data placed the former two species in separate lineages of the Microbotryomycetidae: R . colostri in the "ruineniae clade" (Sporidiobolus lineage or Sporidiobolales) and R . crocea loosely linked to Rhodotorula javanica (Microbotryum lineage). Mikrobiologiia, 2003 Sep-Oct, 72(5), 616 - 20 {The effect of sodium malonate on yeast thermotolerance}; Rikhvanov EG et al.; The study of the effect of malonate (an inhibitor of the succinate dehydrogenase complex of the respiratory chain of mitochondria) on the thermotolerance of the fermentative Saccharomyces cerevisiae and nonfermentative Rhodotorula rubra yeasts showed that malonate augmented the damaging effect of heat shock on the yeasts utilizing glucose (or other sugars) by means of oxidative phosphorylation . At the same time, malonate did not influence and sometimes even improved the thermotolerance of the yeasts utilizing glucose through fermentation . The suggestion is made that cell tolerance to heat shock depends on the normal functioning of mitochondria . On the other hand, their increased activity at elevated temperatures may accelerate the formation of cytotoxic reactive oxygen species and, hence, is not beneficial to cells. J Appl Microbiol, 2004, 96(1), 69 - 75 Suppression of Rhizoctonia solani diseases of sugar beet by antagonistic and plant growth-promoting yeasts; El-Tarabily KA; AIMS: Isolates of Candida valida, Rhodotorula glutinis and Trichosporon asahii from the rhizosphere of sugar beet in Egypt were examined for their ability to colonize roots, to promote plant growth and to protect sugar beet from Rhizoctonia solani AG-2-2 diseases, under glasshouse conditions . METHODS AND RESULTS: Root colonization abilities of the three yeast species were tested using the root colonization plate assay and the sand-tube method . In the root colonization plate assay, C . valida and T . asahii colonized 95% of roots after 6 days, whilst Rhod . glutinis colonized 90% of roots after 8 days . Root-colonization abilities of the three yeast species tested by the sand-tube method showed that roots and soils attached to roots of sugar beet seedlings were colonized to different degrees . Population densities showed that the three yeast species were found at all depths of the rhizosphere soil adhering to taproots up to 10 cm, but population densities were significantly (P < 0.05) greater in the first 4 cm of the root system compared with other root depths . The three yeast species, applied individually or in combination, significantly (P < 0.05) promoted plant growth and reduced damping off, crown and root rots of sugar beet in glasshouse trials . The combination of the three yeasts (which were not inhibitory to each other) resulted in significantly (P < 0.05) better biocontrol of diseases and plant growth promotion than plants exposed to individual species . CONCLUSIONS: Isolates of C . valida, Rhod . glutinis and T . asahii were capable of colonizing sugar beet roots, promoting growth of sugar beet and protecting the seedlings and mature plants from R . solani diseases . This is the first successful attempt to use yeasts as biocontrol agents against R . solani which causes root diseases . SIGNIFICANCE AND IMPACT OF THE STUDY: Yeasts were shown to provide significant protection to sugar beet roots against R . solani, a serious soil-borne root pathogen . Yeasts also have the potential to be used as biological fertilizers. Mycoses, 2003 Dec, 46(11-12), 492 - 5 Experimental evaluation of antifungal and antiseptic agents against Rhodotorula spp; Preney L et al.; We studied the susceptibility of 21 strains of Rhodotorula rubra and nine strains of R . glutinis to eight antifungals and tested eight antiseptic agents on one strain of R . rubra . The tested strains were susceptible to ketoconazole, 5-fluorocytosine, amphotericin B, and nystatin, intermediate to econazole and resistant to fluconazole, itraconazole and miconazole . After 5-min contact, six of the eight antiseptic agents tested showed a fungicidal activity on the tested R . rubra strain. Mycoses, 2003 Dec, 46(11-12), 487 - 91 Genotyping of clinical Rhodotorula mucilaginosa isolates by pulsed field gel electrophoresis; Saracli MA et al.; Identification and typing of fungal isolates is a prerequisite for control and prevention of nosocomial infections . As the discriminatory power of phenotypic methods is not sufficient for epidemiological purposes, genotyping methods such as DNA fingerprinting, random amplification of polymorphic DNA (RAPD) analysis, or pulsed field gel electrophoresis (PFGE) are preferred . To our knowledge, this study is the first application of PFGE for typing Rhodotorula mucilaginosa strains . The PFGE patterns of six clinical isolates produced two different karyotypes, which were confirmed by RAPD analysis . Five strains isolated from bloodstream infections from three different institutions showed the same karyotype and RAPD patterns, while the urological specimen differed slightly. Clin Microbiol Infect, 2003 Aug, 9(8), 897 - 900 Recurrent catheter-related Rhodotorula rubra infection; Lo Re V et al.; A 34-year-old male receiving chronic parenteral nutrition for treatment of short bowel syndrome and intermittent immunosuppressive agents for juvenile rheumatoid arthritis developed recurrent, catheter-associated Rhodotorula rubra fungemia over a one-year period . Infection with this yeast is associated with insertion of central venous catheters . Recurrence of R . rubra infection is an unusual event that presumably occurred because of chronic skin colonization by the organism. J Clin Microbiol, 2003 Nov, 41(11), 5233 - 5 Risk of fungemia due to Rhodotorula and antifungal susceptibility testing of Rhodotorula isolates; Zaas AK et al.; Rhodotorula infections occur among patients with immunosuppression and/or central venous catheters . Using standardized methods (NCCLS M27-A), we determined the antifungal susceptibilities of 10 Rhodotorula bloodstream infection isolates . Patient information was collected for clinical correlation . The MICs of amphotericin B and posaconazole were the lowest, and the MICs of triazoles and echinocandins were higher than those of other antifungal agents. Int J Occup Med Environ Health, 2003, 16(3), 221 - 30 Mould specific IgG antibodies connected with sinusitis in teachers of mould damaged school: a two-year follow-up study; Patovirta RL et al.; OBJECTIVES: The aim of this study was to describe the relationship between mould exposure induced by moisture damage and mould specific immunoglobulin G antibodies to 20 common mould species and their association with respiratory diseases . MATERIALS AND METHODS: Mould specific immunoglobulin G (IgG) antibodies were monitored in teachers in a follow-up after an extensive mould remediation process in school buildings . IgG antibodies to 20 different microbes were determined from the sera of 26 teachers (19 exposed and 7 references) by enzyme-linked immunosorbent assay (ELISA) . The serum samples were drawn twice, firstly at the completion of the remediation in the spring of 1997 and secondly, two years later in the spring of 1999 . Health data was collected with self-administered questionnaires . RESULTS: No statistical differences were found in the overall concentrations of 20 mould-specific IgG-antibodies between the study and control groups at the beginning of the study . An association between sinusitis and elevated mould-specific IgG-levels forAspergillus fumigatus, Aspergillus versicolor, Aureobasidium pullulans, Chaetomium globosum, Cladosporium cladosporioides, Phialophora bubakii, Rhodotorula glutinis, Sporobolomyces salmonicolor, Stachybotrys atra, and Tritirachium roseum was found in the study group . CONCLUSIONS: In a two-year follow-up the total concentration of the IgG antibodies for Tr . toseum was lower at the end than at the beginning of the follow-up and this remained significant for the group of teachers with sinusitis . The decrease in mould specific IgG to Cl . cladosporioides, Geotrichum candidum, Ph . bubakii and Rhizopus nigricans was associated with bronchitis . According to our knowledge, this is the first study in which the association between elevated mould specific IgG antibodies and sinusitis was found in the school environment. Mycol Res, 2003 Aug, 107(Pt 8), 949 - 56 Rhodotorulic acid production by Rhodotorula mucilaginosa; Andersen D et al.; Rhodotorula mucilaginosa produces the siderophore rhodotorulic acid (RA) when grown in iron-limited conditions . R . mucilaginosa grew at rates between 0.10 and 0.19 h(-1) in iron-restricted conditions, depending on the carbon source, and at 0.23 h(-1) in iron-sufficient conditions . In bioreactors inoculated with iron-starved pre-cultures, initial specific growth rates in batch culture were dependent on the iron concentration . The critical dilution rate (Dcrit, at which steady state cultures cannot be sustained) in continuous cultures was also dependent on the iron concentration and was lower than mu(max) in batch culture . Sucrose was the best carbon source for RA production {287+/-11 micromol (g biomass)(-1)} and production could be further increased by supplementing the medium with the precursors acetate {460+/-13 micromol (g biomass)(-1)}, ornithine {376+/-6 micromol (g biomass)(-1)}, or both {539+/-15 micromol (g biomass)(-1)} . Citric acid was an effective suppresser of RA production . RA was produced in a growth rate dependent manner and was optimally produced at pH 6.5. Mikrobiologiia, 2003 Jul-Aug, 72(4), 476 - 81 {The absence of direct relationship between the ability of yeasts to grow at elevated temperatures and their survival after lethal heat shock}; Rikhvanov EG et al.; The study of the growth of the yeasts Rhodotorula rubra, Saccharomyces cerevisiae, and Debaryomyces vanriji at elevated temperatures and their survival after transient lethal heat shock showed that the ability of these yeasts to grow at supraoptimal temperatures (i.e., their thermoresistance) and their ability to tolerate lethal heat shocks (i.e., their thermotolerance) are determined by different mechanisms . The thermotolerance of the yeasts is suggested to be mainly determined by the division rate of cells before their exposure to heat shock. Extremophiles, 2003 Dec, 7(6), 499 - 504 Epub 2003 Oct 01. Na+-mediated piezoprotection in Rhodotorula rubra; Aertsen A et al.; Sodium concentrations as low as 2 mM exerted a significant protective effect on the high-pressure inactivation (160-210 MPa) of Rhodotorula rubra at pH 6.5, but not on two other yeasts tested (Schizosaccharomyces pombe and Saccharomyces cerevisiae) . A piezoprotective effect of similar magnitude was observed with Li+ (2 and 10 mM), and at elevated pH (8.0-9.0), but no effect was seen with K+, Ca2+, Mg2+, Mn2+, or NH4(+) . Intracellular Na+ levels in cells exposed to low concentrations of Na+ or to pH 8.0-9.0 provided evidence for the involvement of a plasma membrane Na+/H+ antiporter and a correlation between intracellular Na+ levels and pressure resistance . The results support the hypothesis that moderate high pressure causes indirect cell death in R . rubra by inducing cytosolic acidification. Bioprocess Biosyst Eng, 2003 Mar, 25(5), 271 - 7 Epub 2003 Feb 01. Characterization of Pb2+ biosorption from aqueous solution by Rhodotorula glutinis; Cho DH et al.; The yeast Rhodotorula glutinis was examined for its ability to remove Pb(2+) from aqueous solution . Within 10 min of contact, Pb(2+) sorption reached nearly 80% of the total Pb(2+) sorption . The optimum initial pH value for removal of Pb(2+ )was 4.5-5.0 . The percentage sorption increased steeply with the biomass concentration up to 2 g/l and thereafter remained more or less constant . Temperature in the range 15-45 degrees C did not show any significant difference in Pb(2+ )sorption by R . glutinis . The light metal ions such as Na(+), K(+), Ca(2+), and Mg(2+) did not significantly interfere with the binding . The Langmuir sorption model provided a good fit throughout the concentration range . The maximum Pb(2+ )sorption capacity q(max) and Langmuir constant b were 73.5 mg/g of biomass and 0.02 l/mg, respectively . The mechanism of Pb(2+) removal by R . glutinis involved biosorption by direct biosorptive interaction with the biomass through ion exchange and precipitation by phosphate released from the biomass. Yeast, 2003 Sep, 20(12), 1061 - 9 Regulation of D-amino acid oxidase expression in the yeast Rhodotorula gracilis; Molla G et al.; Rhodotorula gracilis is a oleaginous yeast which utilizes D-amino acids as a source of carbon and/or nitrogen . D-amino acid oxidase (DAAO), which converts D-amino acids in the corresponding alpha-keto acids and ammonia, is the first enzyme involved in the catabolism of D-amino acids . DAAO activity is induced by the presence of D-alanine, but the presence of the L-isomer prevents induction by inhibiting the transport of D-alanine into cells . To understand how DAAO expression is regulated, R . gracilis cells were grown on media containing different nitrogen and/or carbon sources . As a general rule, the level of DAAO mRNA reached a maximum after 15 h growth and preceded by approximately 6 h the maximum level of DAAO activity . The inducer D-alanine acts by increasing the rate of DAAO mRNA transcription: the increase in DAAO expression is due essentially to de novo synthesis . The presence of a supplemental carbon source (e.g . succinate or glucose) does not repress DAAO expression . Ammonium sulphate appears to have a negative effect on DAAO mRNA translation and on the expression of DAAO activity: DAAO is only partially active when the yeast is grown in the presence of D-alanine and ammonium sulphate . The best expression of DAAO activity was obtained by growing the cells for 12 h at 30 degrees C in the presence of glucose and D-alanine using cells pre-cultured for 10 h on glucose and L-alanine (0.99 U/mg protein, corresponding to approximately 1.0% total proteins in the crude extract) . Under these growth conditions a six-fold increase in DAAO production was achieved . Mycoses, 2003 Sep, 46(8), 293 - 8 The yeast species causing fungemia at a university hospital in Riyadh, Saudi Arabia, during a 10-year period; Al-Hedaithy SS; This study is a retrospective investigation to determine the species of yeasts causing fungemia in a university hospital in Saudi Arabia during the years 1991-2000 . A total of 189 episodes of fungemia were encountered, of which 121 (64%) occurred during 1991-1995, whereas only 68 cases (36%) were found between 1996 and 2000 . Overall, 50.3% episodes were due to Candida albicans including five episodes of C . dubliniensis, followed by C . tropicalis (27%), C . parapsilosis (7.9%), C . glabrata (7.4%), C . krusei (3.2%), C . famata (1.0%); 3.2% were due to other species, namely Blastoschizomyces capitatus, Hansenula anomala, Rhodotorula rubra, and Trichosporon beigelii . The percentage of episodes of fungemia caused by C . albicans ranged from 36.4% in 1991 to 71.4% in 2000, revealing an increase in recent years . The incidence of non-C . albicans fungemia decreased from 63 (33.3%) during the first 5 years (1991-1995) to 31 (16.4%) episodes during the second 5 years . Moreover, no fungemia due to C . glabrata and C . krusei were observed during the last 3 years . Overall, during the years of the study, a decreasing incidence of yeast fungemia was observed . Fungemia occurred more frequently in patients with leukemia (24%), prematurity (16%), postsurgery (10.6%), and lymphoma (9.5%) . Patients with respiratory infections and preterm infants more often had C . albicans fungemia, whereas C . tropicalis predominated in patients with hepatic disorders and leukemia . The study reports for the first time the involvement of C . dubliniensis in yeast fungemia occurring in Saudi Arabia. J Appl Microbiol, 2003, 95(3), 584 - 90 Stability of beta-carotene in spray dried preparation of Rhodotorula glutinis mutant 32; Bhosale P et al.; AIMS: To obtain beta-carotene-rich dry cell preparation from mutant 32 of Rhodotorula glutinis and determination of its pigment stability . METHODS AND RESULTS: The mutant 32 of R . glutinis was grown in a 14 l stirred tank fermenter . Cell mass was concentrated 10-fold by cross-flow microfiltration and then spray dried . Butylated hydroxy toluene (BHT) and d-tocopherol were used as protecting agents . A two-level, three-variable, factorial optimization was performed to achieve moisture-free, non-viable and beta-carotene-rich feed additive . CONCLUSIONS: The beta-carotene and cell mass in stirred tank fermenter were found to be 54 +/- 5 mg l-1 and 12.8 +/- 2 g l-1, respectively . In the presence of BHT, 97 +/- 3% (w/w) beta-carotene was recovered for all the inlet temperatures studied . The best beta-carotene and yeast powder recoveries were obtained at 160 degrees C, 11.6% (w/v) cell mass concentration and 1 g l-1 BHT . The pigments inside dried yeast powder were stable in dark and cold condition for at least 10 weeks . The purified beta-carotene got almost totally denatured, under similar conditions of storage, within 76 h . SIGNIFICANCE AND IMPACT OF THE STUDY: Spray dried and stable preparation of beta-carotene-rich yeast, R . glutinis can provide alternative source of beta-carotene for use in animal nutrition. Appl Environ Microbiol, 2003 Aug, 69(8), 4611 - 7 Curvularia haloperoxidase: antimicrobial activity and potential application as a surface disinfectant; Hansen EH et al.; A presumed antimicrobial enzyme system, the Curvularia haloperoxidase system, was examined with the aim of evaluating its potential as a sanitizing agent . In the presence of hydrogen peroxide, Curvularia haloperoxidase facilitates the oxidation of halides, such as chloride, bromide, and iodide, to antimicrobial compounds . The Curvularia haloperoxidase system caused several-log-unit reductions in counts of bacteria (Pseudomonas spp., Escherichia coli, Serratia marcescens, Aeromonas salmonicida, Shewanella putrefaciens, Staphylococcus epidermidis, and Listeria monocytogenes), yeasts (Candida sp . and Rhodotorula sp.), and filamentous fungi (Aspergillus niger, Aspergillus tubigensis, Aspergillus versicolor, Fusarium oxysporum, Penicillium chrysogenum, and Penicillium paxilli) cultured in suspension . Also, bacteria adhering to the surfaces of contact lenses were killed . The numbers of S . marcescens and S . epidermidis cells adhering to contact lenses were reduced from 4.0 and 4.9 log CFU to 1.2 and 2.7 log CFU, respectively, after treatment with the Curvularia haloperoxidase system . The killing effect of the Curvularia haloperoxidase system was rapid, and 10(6) CFU of E . coli cells/ml were eliminated within 10 min of treatment . Furthermore, the antimicrobial effect was short lived, causing no antibacterial effect against E . coli 10 min after the system was mixed . Bovine serum albumin (1%) and alginate (1%) inhibited the antimicrobial activity of the Curvularia haloperoxidase system, whereas glucose and Tween 20 did not affect its activity . In conclusion, the Curvularia haloperoxidase system is an effective sanitizing system and has the potential for a vast range of applications, for instance, for disinfection of contact lenses or medical devices. Mikrobiologiia, 2003 May-Jun, 72(3), 312 - 9 {Influence of the degree of aeration on halotolerance of yeasts of the genera Candida, Rhodotorula, and Malassezia}; Geidebrekht OV et al.; The biochemical mechanisms were studied that determine different reactions of yeasts of different genera to two simultaneously imposed stressors, hypoxia and osmotic shock . For Candida lipolytica, these two stressors were antagonistic, which resulted in stimulation of yeast growth by NaCl (in a wide range of concentrations) under microaerobic conditions . The reaction of Malassezia sp . was different: the degree of halotolerance of this microorganism was lower under microaerobic conditions . An intervening reaction pattern was characteristic of Rhodotorula aurantiaca . These differences were found to be determined, above all, by the induction of a salt-resistant respiratory system (oxidase) in Candida lipolytica, which could not be induced in Malassezia sp . In addition, the synthesis of catalase was enhanced in Candida lipolytica, which provided for neutralization of the active forms of oxygen accumulating as a result of inhibition of other protective enzymes by salt. Int J Food Microbiol, 2003 Sep 1, 86(1-2), 201 - 7 Yeast associated with spontaneous fermentations of white wines from the "Txakoli de Bizkaia" region (Basque Country, North Spain); Rementeria A et al.; The microbiota of eight spontaneous fermentation of white wine from different grape varieties and different wineries from the "Txakoli de Bizkaia" region (Basque country, North Spain), in 1996 and 1997 campaigns was studied . The yeast population was higher in grapes harvested in 1997, in which late summer and early autumn was warmer and drier . Eight species belonging to five genera were identified in total . The most frequent genera in grapes were Rhodotorula in 1996 and Kloeckera in 1997 . Saccharomyces bayanus was the most frequent species during vigorous and final fermentation, and it was occasionally isolated from grapes and must . Only another Saccharomyces spp., i.e., S . kluyvery, was identified in some samples from 1997. Biotechnol Lett, 2003 May, 25(9), 675 - 80 Biocatalysis of nitro substituted styrene oxides by non-conventional yeasts; Yeates CA et al.; Yeast strains (410) from more than 45 different genera were screened for the enantioselective hydrolysis of nitro substituted styrene oxides . These strains included 262 yeasts with known epoxides hydrolase activity for various other epoxides . Epoxide hydrolase activity for p-nitrostyrene oxide (pNSO) (177 strains) and m-nitrostyrene oxide (mNSO) (148 strains) was widespread in the yeasts, while activity for o-nitrostyrene oxide (oNSO) was less ubiquitous (22 strains) . The strains that displayed enantioselectivity in the hydrolysis of one or more of the nitro substituted styrene oxides (35 strains) were also screened against styrene oxide (SO) . Rhodosporidium toruloides UOFS Y-0471 displayed the highest enantioselectivity for pNSO (ee 55%, yield 35%) while Rhodotorula glutinis UOFS Y-0653 displayed the highest enantioselectivity for mNSO (ee > 98%, yield 29%), oNSO (ee 39%, yield 19%) and SO (ee > 98%, yield 19%) . (R)-Styrene oxide was preferentially hydrolysed to the corresponding (R)-diol with retention of configuration at the stereogenic centre . In the case of the nitro substituted styrene oxides the absolute configurations of the remaining epoxides and the formed diols were not established. J Biol Chem, 2003 Sep 26, 278(39), 37648 - 57 Epub 2003 Jul 16. Nonorganellar acyl carrier protein from oleaginous yeast is a homologue of ribosomal protein P2; Raychaudhuri S et al.; Acyl carrier protein (ACP) is responsible for carrying the growing fatty acid chain from one enzyme active site to the next during fatty acid biosynthesis . Here we report the identification, purification, immunocytochemical localization, and cloning of ACP from the oleaginous yeast, Rhodotorula glutinis . The soluble fraction of this organism can synthesize triacylglycerol and is able to accept the acyl group from acyl-ACP for the synthesis . The ACP, cloned from the system, showed a significant similarity with ribosomal protein P2 . Expression and characterization of the recombinant protein showed that the ACP was acylated in vitro . The recombinant protein was post-translationally modified, since it was observed in {14C}beta-alanine labeling and matrix-assisted laser desorption mass spectroscopic analysis . Site-directed mutants were generated to identify a serine residue responsible for phosphopantetheinylation and found that mutation of serine 59 to alanine abrogated the fatty acylation ability of the protein . These results demonstrate that a novel modification of ribosomal protein P2 allows it to act as an acyl carrier protein and participate in acylation reactions. Planta Med, 2003 Jun, 69(6), 574 - 6 A new azoxyalkene from a strain of an actinomadura-like fungus; Bianchi G et al.; A new proximal alpha,beta-( cis)-unsaturated azoxyalkene (1) was produced by a fungal strain named A7, identified as Actinomadura sp., isolated from apricot (Prunus armeniaca) roots . Compound 1 was isolated together with the polyene macrolide fungichromine, and its structure and geometry were established mainly by UV, MS and 1H- and 13C-NMR mono-dimensional and two-dimensional experiments . Compound 1 showed a weak antibiotic activity against Rhodotorula sp. Chem Pharm Bull (Tokyo), 2003 Jun, 51(6), 646 - 8 Microbial metabolites of harman alkaloids; Herath W et al.; Several microorganisms showed the ability to transform the harman alkaloids, harmaline (1), harmalol (2) and harman (5) . Harmaline (1) and harmalol (2) were converted by Rhodotorula rubra ATCC 20129 into the tryptamines, 2-acetyl-3-(2-acetamidoethyl)-7-methoxyindole (3) and 2-acetyl-3-(2-acetamidoethyl)-7-hydroxyindole (4), respectively . Harman (5) was biotransformed by Cunninghamella echinulata NRRL 3655 into 6-hydroxyharman (6) and harman-2-oxide (7). Int J Syst Evol Microbiol, 2003 May, 53(Pt 3), 897 - 903 Rhodotorula benthica sp . nov . and Rhodotorula calyptogenae sp . nov., novel yeast species from animals collected from the deep-sea floor, and Rhodotorula lysiniphila sp . nov., which is related phylogenetically; Nagahama T et al.; Three novel species of the genus Rhodotorula are described . Rhodotorula benthica sp . nov . (type strain JCM 10901(T) = SY-91(T)) and Rhodotorula calyptogenae sp . nov . (type strain JCM 10899(T) = SY-86(T)) were respectively isolated from the tubeworm Lamellibrachia sp . and the giant white clam Calyptogena sp., collected from the deep-sea floor of the Pacific Ocean off Japan . Rhodotorula lysiniphila sp . nov . (type strain JCM 5951(T)) is proposed for strains isolated previously in Japan and Pakistan . The three species were placed phylogenetically into a species complex comprising Rhodotorula laryngis, Rhodotorula minuta, Rhodotorula pallida and Rhodotorula slooffiae . R . minuta and R . slooffiae are closely related in both the D1/D2 region of the 26S rDNA and the internal transcribed spacer and 5.8S rDNA regions . R . benthica and R . laryngis were closer to R . pallida based on the D1/D2 region . Other relationships were not clear. Biotechnol Prog, 2003 May-Jun, 19(3), 784 - 8 Use of physicochemical tools to determine the choice of optimal enzyme: stabilization of D-amino acid oxidase; Betancor L et al.; An evaluation of the stability of several forms (including soluble and two immobilized preparations) of d-amino acid oxidases from Trigonopsis variabilis (TvDAAO) and Rhodotorula gracilis (RgDAAO) is presented here . Initially, both soluble enzymes become inactivated via subunit dissociation, and the most thermostable enzyme seemed to be TvDAAO, which was 3-4 times more stable than RgDAAO at a protein concentration of 30 microg/mL . Immobilization on poorly activated supports was unable to stabilize the enzyme, while highly activated supports improved the enzyme stability . Better results were obtained when using highly activated glyoxyl agarose supports than when glutaraldehyde was used . Thus, multisubunit immobilization on highly activated glyoxyl agarose dramatically improved the stability of RgDAAO (by ca . 15,000-fold) while only marginally improving the stability of TvDAAO (by 15-20-fold), at a protein concentration of 6.7 microg/mL . Therefore, the optimal immobilized RgDAAO was much more stable than the optimal immobilized TvDAAO at this enzyme concentration . The lower stabilization effect on TvDAAO was associated with the inactivation of this enzyme by FAD dissociation that was not prevented by immobilization . Finally, nonstabilized RgDAAO was marginally more stable in the presence of H(2)O(2) than TvDAAO, but after stabilization by multisubunit immobilization, its stability became 10 times higher than that of TvDAAO . Therefore, the most stable DAAO preparation and the optimal choice for an industrial application seems to be RgDAAO immobilized on glyoxyl agarose. Infection, 2003 Jun, 31(3), 181 - 3 Aortic homograft endocarditis caused by Rhodotorula mucilaginosa; Maeder M et al.; Serious infections caused by Rhodotorula spp . are rare and usually occur in immunocompromised people, especially in patients with tumors and long-time use of indwelling central venous catheters . We report a case of Rhodotorula mucilaginosa homograft endocarditis in an otherwise healthy man, which was successfully treated by surgery in combination with amphotericin B and subsequently intraconazole. Environ Toxicol Chem, 2003 Jun, 22(6), 1244 - 51 Biodegradation of plasticizers by Rhodotorula rubra; Gartshore J et al.; The degradation of plasticizers by the yeast Rhodotorula rubra J-96-1 (American Type Culture Collection 9449) in the presence of glucose was studied . The plasticizers included the commonly used bis-2-ethylhexyl adipate (B(EH)A), dioctyl phthalate (DOP), and dioctyl terephthalate (DOTP), and the less commonly used dipropylene glycol dibenzoate (D(PG)DB) and diethylene glycol dibenzoate (D(EG)DB) . The proposal had been made that the latter two plasticizers be used as alternatives to the first three, which have been associated with negative environmental impacts . The degradation of D(PG)DB or D(EG)DB led to a significant increase in solution toxicity, which was associated with the production of metabolites resulting from the incomplete breakdown of the plasticizers . The toxic metabolites in the D(PG)DB system were identified as isomers of dipropylene glycol monobenzoate . A pathway for the formation of this metabolite was proposed . The metabolite observed when D(EG)DB was being degraded was tentatively identified as diethylene glycol monobenzoate by analogy to the D(PG)DB system . In contrast, no metabolites were observable and toxicity did not increase in the media during the degradation of B(EH)A, DOP, or DOTP by R . rubra . Collectively, these results do not support the use of D(PG)DB and D(EG)DB as environmentally safe alternatives to B(EH)A, DOP, or DOTP. J Ind Microbiol Biotechnol, 2003 Aug, 30(8), 456 - 61 Epub 2003 May 21. Heterologous production of flavanones in Escherichia coli: potential for combinatorial biosynthesis of flavonoids in bacteria; Kaneko M et al.; Chalcones, the central precursor of flavonoids, are synthesized exclusively in plants from tyrosine and phenylalanine via the sequential reaction of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate:coenzyme A ligase (4CL) and chalcone synthase (CHS) . Chalcones are converted into the corresponding flavanones by the action of chalcone isomerase (CHI), or non-enzymatically under alkaline conditions . PAL from the yeast Rhodotorula rubra, 4CL from an actinomycete Streptomyces coelicolor A3(2), and CHS from a licorice plant Glycyrrhiza echinata, assembled as artificial gene clusters in different organizations, were used for fermentation production of flavanones in Escherichia coli . Because the bacterial 4CL enzyme attaches CoA to both cinnamic acid and 4-coumaric acid, the designed biosynthetic pathway bypassed the C4H step . E . coli carrying one of the designed gene clusters produced about 450 microg naringenin/l from tyrosine and 750 microg pinocembrin/l from phenylalanine . The successful production of plant-specific flavanones in bacteria demonstrates the usefulness of combinatorial biosynthesis approaches not only for the production of various compounds of plant and animal origin but also for the construction of libraries of "unnatural" natural compounds. Mikrobiologiia, 2003 Mar-Apr, 72(2), 174 - 9 {Effect of cytochrome oxidase inhibitors on the yeast thermotolerance}; Rikhvanov EG et al.; The investigation of the effect of the cytochrome oxidase inhibitors sodium cyanide and sodium azide on the thermotolerance of the yeasts Rhodotorula rubra, Debaryomyces vanriji, and Saccharomyces cerevisiae showed that these inhibitors diminish the thermotolerance of R . rubra and D . vanriji, but do not affect the thermotolerance of S . cerevisiae . Taking into account the fact that, unlike the latter yeast, R . rubra and D . vanriji are nonfermentative yeasts, the difference in the effects of the inhibitors on the yeast thermotolerance can be readily explained by the different types of glucose utilization (either oxidative or fermentative) in these yeasts . The data obtained also provide evidence that there is a correlation between the functional activity of mitochondria and the thermotolerance of yeast cells. Appl Environ Microbiol, 2003 May, 69(5), 2699 - 706 Production of plant-specific flavanones by Escherichia coli containing an artificial gene cluster; Hwang EI et al.; In plants, chalcones are precursors for a large number of flavonoid-derived plant natural products and are converted to flavanones by chalcone isomerase or nonenzymatically . Chalcones are synthesized from tyrosine and phenylalanine via the phenylpropanoid pathway involving phenylalanine ammonia lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate:coenzyme A ligase (4CL), and chalcone synthase (CHS) . For the purpose of production of flavanones in Escherichia coli, three sets of an artificial gene cluster which contained three genes of heterologous origins--PAL from the yeast Rhodotorula rubra, 4CL from the actinomycete Streptomyces coelicolor A3(2), and CHS from the licorice plant Glycyrrhiza echinata--were constructed . The constructions of the three sets were done as follows: (i) PAL, 4CL, and CHS were placed in that order under the control of the T7 promoter (P(T7)) and the ribosome-binding sequence (RBS) in the pET vector, where the initiation codons of 4CL and CHS were overlapped with the termination codons of the preceding genes; (ii) the three genes were transcribed by a single P(T7) in front of PAL, and each of the three contained the RBS at appropriate positions; and (iii) all three genes contained both P(T7) and the RBS . These pathways bypassed C4H, a cytochrome P-450 hydroxylase, because the bacterial 4CL enzyme ligated coenzyme A to both cinnamic acid and 4-coumaric acid . E . coli cells containing the gene clusters produced two flavanones, pinocembrin from phenylalanine and naringenin from tyrosine, in addition to their precursors, cinnamic acid and 4-coumaric acid . Of the three sets, the third gene cluster conferred on the host the highest ability to produce the flavanones . This is a new metabolic engineering technique for the production in bacteria of a variety of compounds of plant and animal origin. Yeast, 2003 Apr 30, 20(6), 479 - 92 Cu,Zn superoxide dismutase in Rhodotorula and Udeniomyces spp . isolated from sea water: cloning and sequencing the encoding region; Hernandez-Saavedra NY; The gene encoding the copper-zinc superoxide dismutase enzyme (SODC or Cu,Zn-SOD) has been cloned from several species of higher eukaryotes, but superoxide dismutase genes from moulds and yeast have not been studied extensively . Only 15 nucleotide sequences have been reported in the SwissProt, EMBL and GenBank data libraries . In general the presence of Cu,Zn-SOD in cytosol, as well as Mn-SOD in the mitochondrial matrix of yeast, has been accepted . The absence of Cu,Zn-SOD in a pigmented yeast has been accepted as a general rule . Some authors suggest that the absence of Cu,Zn-SOD in pigmented yeast is complemented by the presence of carotenoproteins that act as an extra mitochondrial antioxidant . In this report, we found that the absence of SODC is not a rule for pigmented yeast: Udeniomyces puniceus expresses an active SODC which responds to Cu(2+) induction, as has been reported previously for non-pigmented yeast . The encoding region of the sod1 gene was cloned from three species of pigmented marine yeast thorough genomic DNA PCR amplification . Fragments of 485-487 nucleotides were obtained, which contain information for theoretical products of 153-154 amino acids . In Rhodotorula mucilaginosa the deduced amino acid sequence shows that insertion of three bases (C(112), A(149) and C(166)) generates a stop codon at position 123 (TGA) . For Rhodotorula graminis a single change (T for A) generates a stop codon at position 298 . For both species, this non-transcription of encoding sequence correlates with the absence of peptides or active proteins in cell homogenates . For U . puniceus, the cloned nucleotide sequence contains all necessary information to produce a functional protein, which correlates with activity detected in cell homogenates, both under normal conditions and by copper induction experiments . Finally, we clearly showed that the key factor in protection against oxidative stress on pigmented yeast is related not only to the presence of protective pigments but also to their amounts and spectra, as well as the presence and activity of SODC . Protein Sci, 2003 May, 12(5), 1018 - 29 Contribution of the dimeric state to the thermal stability of the flavoprotein D-amino acid oxidase; Pollegioni L et al.; The flavoenzyme DAAO from Rhodotorula gracilis, a structural paradigm of the glutathione-reductase family of flavoproteins, is a stable homodimer with a flavin adenine dinucleotide (FAD) molecule tightly bound to each 40-kD subunit . In this work, the thermal unfolding of dimeric DAAO was compared with that of two monomeric forms of the same protein: a Deltaloop mutant, in which 14 residues belonging to a loop connecting strands betaF5-betaF6 have been deleted, and a monomer obtained by treating the native holoenzyme with 0.5 M NH(4)SCN . Thiocyanate specifically and reversibly affects monomer association in wild-type DAAO by acting on hydrophobic residues and on ionic pairs between the betaF5-betaF6 loop of one monomer and the alphaI3' and alphaI3" helices of the symmetry-related monomer . By using circular dichroism spectroscopy, protein and flavin fluorescence, activity assays, and DSC, we demonstrated that thermal unfolding involves (in order of increasing temperatures) loss of tertiary structure, followed by loss of some elements of secondary structure, and by general unfolding of the protein structure that was concomitant to FAD release . Temperature stability of wild-type DAAO is related to the presence of a dimeric structure that affects the stability of independent structural domains . The monomeric Deltaloop mutant is thermodynamically less stable than dimeric wild-type DAAO (with melting temperatures (T(m)s) of 48 degrees C and 54 degrees C, respectively) . The absence of complications ensuing from association equilibria in the mutant Deltaloop DAAO allowed identification of two energetic domains: a low-temperature energetic domain related to unfolding of tertiary structure, and a high-temperature energetic domain related to loss of secondary structure elements and to flavin release. FEMS Yeast Res, 2003 Apr, 3(2), 159 - 66 Yeasts associated with Manteca; Suzzi G et al.; Manteca is a traditional milk product of southern Italy produced from whey deriving from Caciocavallo Podolico cheese-making . This study was undertaken to obtain more information about the microbiological properties of this product and particularly about the presence, metabolic activities, and technological significance of the different yeast species naturally occurring in Manteca . High numbers of yeasts were counted after 7 days ripening (10(4)-10(5) cfu g(-1)) and then decreased to 10(2) at the end . A total of 179 isolates were identified and studied for their phenotypic and genotypic characteristics . The most frequently encountered species were Trichosporon asahii (45), Candida parapsilosis (33), Rhodotorula mucilaginosa (32), Candida inconspicua (29) . Some of these yeasts showed lipolytic activity (32 strains) and proteolytic activity (29 strains), NaCl resistance up to 10% and growth up to 45 degrees C (42 strains) . Biogenic amines were formed by proteolytic strains, in particular phenylethylamine, putrescine and spermidine . Spermidine was produced by all the yeasts tested in this work, but only Trichosporon produced a great quantity of this compound . Histamine was not detectable . Caseinolytic activity was common to almost all strains, corresponding to the ability to efficiently split off amino-terminal amino acids . The highest and most constant activity expressed by all species was X-prolyl-dipeptidyl aminopeptidase . The findings suggest that the presence of yeasts may play a significant role in justifying interactions with lactic acid bacteria, and consequently with their metabolic activity in the definition of the peculiar characteristics of Manteca cheese. FEMS Yeast Res, 2001 Jul, 1(2), 161 - 7 A survey of yeasts in traditional sausages of southern Italy; Gardini F et al.; The evolution of the yeast population during manufacturing and ripening of 'salsiccia sotto sugna', a typical salami of the Lucania region (southern Italy), was investigated . Four different batches, produced in four farms in Lucania, were studied . Each batch showed a specific yeast population, and the most frequently isolated yeasts belonged to Debaryomyces hansenii and its anamorph Candida famata, and Rhodotorula mucilaginosa . Yarrowia lipolytica was isolated from three sausage batches . The Y . lipolytica isolates were further characterised, in particular for their lipolytic activity on pork fat . Lipolytic activity was maximal at pH 5.5, with oleic and palmitic acids as major free fatty acids produced . The use of randomly amplified polymorphic DNA-polymerase chain reaction allowed the detection of a high genetic heterogeneity among the isolates phenotypically assigned to the species Y . lipolytica. FEMS Yeast Res, 2002 Mar, 2(1), 47 - 58 Polyphasic taxonomy of the basidiomycetous yeast genus Rhodotorula: Rh . glutinis sensu stricto and Rh . dairenensis comb . nov; Gadanho M et al.; The phenotypic and genetic heterogeneity of the basidiomycetous yeast species Rhodotorula glutinis was investigated in a group of 109 isolates . A polyphasic taxonomic approach was followed which included PCR fingerprinting, determination of sexual compatibility, 26S and ITS rDNA sequence analysis, DNA-DNA reassociation experiments and reassessment of micromorphological and physiological attributes . The relationships with species of the teleomorphic genus Rhodosporidium were studied and isolates previously identified as Rh . glutinis were found to belong to Rhodosporidium babjevae, Rhodosporidium diobovatum and Rhodosporidium sphaerocarpum . Other isolates included in the study were found to belong to Rh . glutinis var . dairenensis, which is elevated to the species level, or to undescribed species . The concept of Rh . glutinis sensu stricto is proposed due to the close phenetic and phylogenetic proximity detected for Rh . glutinis, Rhodotorula graminis and R . babjevae. FEMS Yeast Res, 2002 May, 2(2), 159 - 63 Rhodotorula pinicola sp . nov., a basidiomycetous yeast species isolated from xylem of pine twigs; Zhao JH et al.; Three pink-colored yeast strains 3-1-3, 10-3-3 and 19-3-3 were isolated from xylem of surface-sterilized twigs of Pinus tabulaeformis collected from Dongling Mountain, Beijing, in different seasons . These strains were identified as Rhodotorula minuta (Saito) F.C . Harrison by conventional taxonomic characterization . However, molecular phylogenetic analysis based on internal transcribed spacer region (including 5.8S rDNA) and large-subunit rDNA D1/D2 domain sequences indicated that they represent a novel basidiomycetous yeast species, for which Rhodotorula pinicola is proposed (type strain: AS 2.2193(T)=CBS 9130(T)) . The new species was most closely related to Rhodotorula laryngis Reiersol in the R . minuta complex. Biotechnol Bioeng, 2003 May 20, 82(4), 480 - 8 Fusion protein of Vitreoscilla hemoglobin with D-amino acid oxidase enhances activity and stability of biocatalyst in the bioconversion process of cephalosporin C; Khang YH et al.; In this study we constructed an artificial flavohemoprotein by fusing Vitreoscilla hemoglobin (VHb) with D-amino acid oxidase (DAO) of Rhodotorula gracilis to determine whether bacterial hemoglobin can be used as an oxygen donor to immobilized flavoenzyme . This chimeric enzyme significantly enhanced DAO activity and stability in the bioconversion process of cephalosporin C . In a 200-mL bioreactor, the catalytic efficiency of immobilized VHb-DAO against cephalosporin C was 12.5-fold higher than that of immobilized DAO, and the operational stability of the immobilized VHb-DAO was approximately threefold better than that of the immobilized DAO . In the scaled-up bioprocess with a 5-L bioreactor, immobilized VHb-DAO (2500 U/L) resulted in 99% bioconversion of 120 mM cephalosporin C within 60 min at an oxygen flow rate of 0.2 (v/v) x min . Ninety percent of the initial activity of immobilized VHb-DAO could be maintained at up to 50 cycles of the enzymatic reaction without exogenous addition of H(2)O(2) and flavin adenine dinucleotide (FAD) . The purity of the final product, glutaryl-7-aminocephalosporanic acid, was confirmed to be 99.77% by high-performance liquid chromatography (HPLC) analysis . Relative specificity of immobilized VHb-DAO on D-alpha-aminoadipic acid, a precursor in cephalosporin C biosynthesis, increased twofold, compared with that of immobilized DAO, suggesting that conformational modification of the VHb-DAO fusion protein may be altered in favor of cephalosporin C . Biochem J, 2003 Jun 1, 372(Pt 2), 587 - 94 Cytosolic iron superoxide dismutase is a part of the triacylglycerol biosynthetic complex in oleaginous yeast; Raychaudhuri S et al.; A novel multienzyme complex for the biosynthesis of triacylglycerol in oleaginous yeast has been identified recently in the cytosol and characterized {Gangar, Karande and Rajasekharan (2001) J . Biol . Chem . 276, 10290-10298} . Screening the library of Rhodotorula glutinis with an oligonucleotide probe derived from the N-terminal sequence of one of the protein components in the complex (21 kDa protein) resulted in the isolation of a 0.7 kb cDNA . Nucleotide sequence analysis revealed that the isolated gene codes for superoxide dismutase (SOD) . Atomic absorption spectroscopy and inhibition assays showed that this cytosolic SOD utilizes Fe as its cofactor . Enzymic assays, immunoprecipitation and cross-linking experiments revealed that SOD is a part of the triacylglycerol biosynthetic complex, which could protect the substrate and the complex from oxidative damages . These results indicate for the first time the presence of iron-containing SOD in a soluble form in yeast. J Clin Microbiol, 2003 Feb, 41(2), 857 - 9 Catheter-related sepsis due to Rhodotorula glutinis; Hsueh PR et al.; We describe a central venous catheter-related (Port-A-Cath; Smiths Industries Medical Systems {SIMS} Deltec, Inc., St . Paul, Minn.) infection caused by Rhodotorula glutinis in a 51-year-old man with nasopharyngeal carcinoma . He was treated with fluconazole for 8 weeks and had the catheter removed . Two isolates of R . glutinis recovered from blood specimens (one obtained via peripheral veins and one via the catheter) before administration of fluconazole and one recovered from the removed catheter 17 days after initiation of fluconazole therapy exhibited high-level resistance to fluconazole (MICs, >256 microg/ml) . These three isolates were found to belong to a single clone on the basis of identical antibiotypes determined by the E test (PDM Epsilometer; AB Biodisk, Solna, Sweden) and biotypes determined by API ID32 C (bioMerieux, Marcy I'Etoile, France) and their identical random amplified polymorphic DNA patterns. J Gen Appl Microbiol, 2001 Aug, 47(4), 213 - 221 Phenol degradation by yeasts isolated from industrial effluents; Santos VL et al.; Yeast strains of the genera Aureobasidium, Rhodotorula and Trichosporon were isolated from stainless steel effluents and tested for their ability to utilize phenol as the sole carbon source . Fourteen strains grew in the presence of up to 10 mm phenol . Only the strain Trichosporon sp . LE3 was able to grow in the presence of up to 20 mm phenol . An inhibitory effect was observed at concentrations higher than 11 mm, resulting in reduction of specific growth rates . Phenol degradation was a function of strain, time of incubation and initial phenol concentration . All strains exhibited activity of catechol 1,2-dioxygenase and phenol hydroxylase in free cell extracts from cells grown on phenol, suggesting that catechol was oxidized by the ortho type of ring fission . Addition of glucose and benzoate reduced the phenol consumption rate, and both substrates were used simultaneously . Glucose concentrations higher than 0.25% inhibited the induction of phenol oxidation by non-proliferating cells and inhibited phenol oxidation by pre-induced cells. Microb Ecol, 2003 Jan, 45(1), 53 - 62 Epub 2002 Dec 17. Two endophytic fungi in different tissues of scots pine buds (Pinus sylvestris L.); Pirttila AM et al.; Two fungal species were isolated with different frequencies from pine tissue cultures originating from buds . One species was detected in 33.1% of the cultures initiated in March, and another was present in 1.7% of cultures initiated in June . Based on analyses of phylogenetic and physiological characteristics these fungi were identified as Hormonema dematioides (isolated in March) and Rhodotorula minuta (isolated in June) . Probes targeted towards the 18S rRNA of H . dematioides and R . minuta were made . When in situ hybridizations were performed on pine bud tissue, R . minuta was detected inside the cells of meristematic tissue in 40% of the samples, in contrast to H . dematioides, which was not found in this tissue . Using light microscopy, H . dematioides was found to be localized in the scale tissues of the buds . Fungal endophytes have previously been detected in scale tissues, but not in the meristematic tissues of buds . The habitats of these fungi may reflect their different roles in the plant. Biotechnol Bioeng, 2003 Feb 5, 81(3), 323 - 8 Water-in-oil macroemulsions sustain long-term viability of microbial cells in organic solvents; Stefan A et al.; Extremely stable water-in-oil macroemulsions have been obtained by dispersing water in isooctane in the presence of lecithin . Either prokaryotic (Escherichia coli) and eukaryotic (Saccharomyces cerevisiae and Rhodotorula minuta) cells hosted in these water-in-oil macroemulsions are viable for weeks despite the consistent excess of organic solvent (ranging from 70 to 84%, v/v) in these ternary systems . Conjugation occurs upon mixing macroemulsions containing F(+) or F(-) Escherichia coli strains, indicating consistent mass transfer between the water droplets . Populations of yeasts hosted in water-in-oil macroemulsion feature a higher frequency of cells aggregation when compared with the corresponding populations suspended in homogeneous aqueous media . J Mol Biol, 2002 Nov 29, 324(3), 535 - 46 Yeast D-amino acid oxidase: structural basis of its catalytic properties; Pollegioni L et al.; The 3D structure of the flavoprotein D-amino acid oxidase (DAAO) from the yeast Rhodotorula gracilis (RgDAAO) in complex with the competitive inhibitor anthranilate was solved (resolution 1.9A) and structural features relevant for the overall conformation and for catalytic activity are described . The FAD is bound in an elongated conformation in the core of the enzyme . Two anthranilate molecules are found within the active site cavity; one is located in a funnel forming the entrance, and the second is in contact with the flavin . The anchoring of the ligand carboxylate with Arg285 and Tyr223 is found for all complexes studied . However, while the active site group Tyr238-OH interacts with the carboxylate in the case of the substrate D-alanine, of D-CF(3)-alanine, or of L-lactate, in the anthranilate complex the phenol group rotates around the C2-C3 bond thus opening the entrance of the active site, and interacts there with the second bound anthranilate . This movement serves in channeling substrate to the bottom of the active site, the locus of chemical catalysis . The absence in RgDAAO of the "lid" covering the active site, as found in mammalian DAAO, is interpreted as being at the origin of the differences in kinetic mechanism between the two enzymes . This lid has been proposed to regulate product dissociation in the latter, while the side-chain of Tyr238 might exert a similar role in RgDAAO . The more open active site architecture of RgDAAO is the origin of its much broader substrate specificity . The RgDAAO enzyme forms a homodimer with C2 symmetry that is different from that reported for mammalian D-amino acid oxidase . This different mode of aggregation probably causes the differences in stability and tightness of FAD cofactor binding between the DAAOs from different sources. J Biomed Sci, 2002 Nov-Dec, 9(6 Pt 2), 645 - 55 Characterization of enolase allergen from Rhodotorula mucilaginosa; Chang CY et al.; Rhodotorula mucilaginosa (also known as R . rubra) is among the most commonly found yeast strains in our environment . However, allergens from R . mucilaginosa have not yet been characterized at the molecular level . The purpose of this study was to characterize the enolase allergen from R . mucilaginosa and examine the allergenic/antigenic cross-reactivity among fungal enolases . The full-length cDNA encoding the R . mucilaginosa enolase was isolated through the reverse transcriptase-polymerase chain reaction in conjunction with the 5'-end and 3'-end rapid amplification cDNA end reactions . The corresponding natural enolase from R . mucilaginosa was identified using two-dimensional gel electrophoresis and N-terminal amino acid sequence analysis . The results showed that the enolase from R . mucilaginosa is a protein of 439 residues and is encoded by a cDNA of 1497 bp . It shares high sequence identity with enolase allergens from Candida albicans (85%), Saccharomyces cerevisiae (76%), Penicillium citrinum (76%), Aspergillus fumigatus (76%), Cladosporium herbarum (76.5%), and Alternaria alternata (74%) . A 47-kD component in the R . mucilaginosa extracts was found to react with IgE or rabbit anti-enolase antiserum and has an N-terminal amino acid sequence identical to that deduced from the isolated enolase cDNA . Sera from three (21%) of 14 allergic patients sensitized to R . mucilaginosa showed IgE binding to this 47-kD R . mucilaginosa component and the His-tagged recombinant enolase . A rabbit antiserum against the P . citrinum enolase and a monoclonal antibody (MoAb; Afueno 8) against the A . fumigatus enolase reacted with all 5 fungal enolases tested . However, an MoAb (E2a) generated by using the Saccharomyces enolase as antigen could only recognize the immunizing enolase . In addition, heterogeneity in immunoblot profiles of IgE antibodies in serum samples from 9 allergic patients against 5 different fungal enolases tested was also observed . The presence of IgE cross-reactivity among enolase allergens from R . mucilaginosa, C . albicans and P . citrinum was detected by immunoblot inhibition . In conclusion, a new and cross-reactive enolase allergen from R . mucilaginosa (Rho m 1) was identified . Although enolases are highly conserved allergens among different fungal species, most of the allergic patients examined in this study differed in their IgE reactivity to the 5 different fungal enolases tested . The results obtained will be of value in understanding the role of enolase allergen in clinical mould allergy . Phytochemistry, 2002 Nov, 61(6), 605 - 9 Invertase from a strain of Rhodotorula glutinis; Rubio MC et al.; An invertase (beta-D-fructofuranoside fructohydrolase, EC 3.2.1.26) from Rhodotorula glutinis was purified by ammonium sulfate fractionation, gel filtration and anion exchange chromatography . Invertase molecular weight was estimated to be 100 kDa by analytical gel filtration and 47 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) . Molecular mass determinations indicated that the native enzyme exists as a homodimer . It is a glycoprotein that contains 19% carbohydrate . The enzyme attacks beta-D-fructofuranoside (raffinose, stachyose and sucrose) from the fructose end . It has a K(m) of 0.227 M and a V(max) of 0.096 micromol/min with sucrose as a substrate . Invertase activity is stable between pH 2.6 and 5.5 for 30 min, maximum activity being observed at pH 4.5 . The activation energy was 6520 cal/mol . The enzyme is stable between 20 and 60 degrees C . Mg(2+) and Ca(2+) ions stimulated invertase activity 3-fold, while Fe(2+), K(+), Co(2+), Na(+) and Cu(2+) increased activity about 2-fold . The transfructosylation reaction could not be observed . This enzyme is of particular interest since it appears to have a high hydrolytic activity in 1 M sucrose solution . This fact would make the enzymatic hydrolysis process economically efficient for syrup production using by-products with high salt and sugar contents such as sugar cane molasses. Acta Pol Pharm, 2002 Jul-Aug, 59(4), 295 - 306 Quantitative structure-activity relationships study of a series of imidazole derivatives as potential new antifungal drugs; Wiktorowicz W et al.; The Quantitative Structure-Activity Relationships (QSAR) has been developed to relate antifungal activity against Candida albicans and Rhodotorula glutinis of new imidazole derivatives with their physico-chemical and structural properties . For 265 imidazole derivatives the most significant statistically equations has been obtained with correlation coefficients R=0.800 and R=0.820 in case of activity against Ca . and Rh.g., respectively . The overall antifungal activity has been described by means of size and bulkiness related parameters as well as polar and lipophilic interactions . The significance of lipophilicity in terms of n-octanol/water partition coefficient, ClogP, on antifungal potency against both fungi has been investigated . QSAR equations for different classes of antifungal activity have been obtained . With a very high probability level (92% and 96%) the weak or very weak antifungal potency against C.a . can be determined and thus the number of required experiments can be reduced. Acta Microbiol Pol, 2002, 51(2), 153 - 69 Continuous production of L-phenylalanine by Rhodotorula glutinis immobilized cells using a column reactor; El-Batal AI; Studies have been conducted on L-phenylalanine (L-Phe) production and phenylalanine ammonia lyase (PAL) stabilization in the presence of several optimum effectors and reducing agents under bioconversion of transcinnamic acid (t-CA) conditions during repeated batch operations . L-Phe production was maximized and reuseability of PAL catalyst was extended to eight consecutive cycles (repeated batches) in the presence of optimum effectors (glutamic acid, polyethylene glycol and glycerol), thioglycolic acid and sparging with nitrogen gas . These best optimum bioconversion conditions desensitize the PAL catalyst to substantially elevated higher substrate t-CA concentrations and inhibit inactivation of PAL enzyme over longer reaction periods compared to the control . The fed batch mode operation of bioconversion of total t-CA (300 mM) to L-Phe was superior (65.2%, conversion), comparing with conventional batch and repeated batch (58.4%, conversion) operations after 120 h . Gamma irradiation process was employed to polymerize and crosslink polyvinyl alcohol (PVA) with N,N'-methylene-bisacrylamide (BIS) agent . The use of immobilized PAL biocatalyst containing cells in PVA-BIS copolymer gel carrier produced by radiation polymerization is obviously advantageous with regards to the yield of L-Phe which was increased in average 1.2-fold when compare to those obtained with free cells during optimum bioconversion process . When comparing the magnitudes of gamma irradiation effects on immobilized entrapped yeast cells in PVA-BIS copolymer gel carrier using scanning electron microscopy it was show that yeast cells were protected and capable to overcome these conditions and had normal shape and other features as free (unirradiated) intact yeast cells . Optimum conditions for continuous production of L-Phe by PVA-BIS copolymer carrier entrapped yeast cells in a packed bed column reactor in recycle fed-batch mode were investigated . Under these optimum conditions L-Phe accumulated to concentration 240.1 mM represts a total conversion yield of 80% (w/w) from (300 mM) t-CA after 84 h of reaction process, which was higher than that obtained after 120 h of reaction, 65.2% (w/w) from (300 mM) t-CA with free cells in fed-batch mode . The results also demonstrated that during about 4 weeks of repeated continuous recycle fed batch mode experiments (using immobilized cells in packed bed reactor), the final production of L-Phe concentrations decreased gradually in eight consecutive runs with no sign of breakage or disintegration of the carrier gel beads. Acta Microbiol Pol, 2002, 51(2), 139 - 52 Optimization of reaction conditions and stabilization of phenylalanine ammonia lyase-containing Rhodotorula glutinis cells during bioconversion of trans-cinnamic acid to L-phenylalanine; El-Batal AI; Studies were performed to elucidate the optimal reaction conditions (pH, temperature, ammonia concentration and biocatalyst loading) for bioconversion of trans-cinnamic acid (t-CA) to L-phenylalanine (L-Phe) by L-phenylalanine ammonia lyase (PAL) containing Rhodotorula glutinis cells . All treatments with permeabilizing agents stimulated L-Phe production and also enhanced instability of the catalyst, except Triton X-100 which gave a superior (56%) increase in conversion as compared to the control and a significant stabilization of PAL enzyme . Inclusion of several activity modifiers and stabilizer additives in reaction mixtures were shown to enhance the yield of L-Phe and maintained PAL stability over several successive incubations during the bioconversion process . Maximum stabilization of PAL and enhancement of L-Phe production was achieved with addition of 20% polyhydric alcohol (glycerol) . The production of L-Phe continued to the fifth cycle and the total yield increased 2.3 times compared to the yield produced by the control (without glycerol addition) during the repeated batch process . Reducing agents such as 2-mercaptoethanol and thioglycolic acid were added to the bioconversion mixture in order to reduce the effects of oxygen on PAL catalyst life . Production of L-Phe by addition of 400 mgL(-1) of thioglycolic acid was maximized over the control by 55% . When both 20% glycerol and 400 mgL(-1) thioglycolic acid were simultaneously present in the