FEBS Lett, 1995 Apr 24, 363(3), 307 - 10 Reactivity of histidyl residues in D-amino acid oxidase from Rhodotorula gracilis; Gadda G et al.; Incubation of D-amino acid oxidase from the yeast Rhodotorula gracilis with excess dansyl chloride at pH 6.6 and 18 degrees C caused an irreversible inactivation of D-amino acid oxidase . Benzoate, a competitive inhibitor of the enzyme, completely protected the enzyme from inactivation . The dansylated-enzyme, isolated by gel-filtration, was in part still active while the substrate specificity was altered substantially . It was completely reduced by D-alanine in anaerobiosic conditions and did stabilize the red anion semiquinone upon photochemical reduction with EDTA . The results provide evidence for the presence of essential histidyl residue(s) in the active center of the yeast enzyme. Clin Infect Dis, 1995 Apr, 20(4), 900 - 6 Fungemia in children infected with the human immunodeficiency virus: new epidemiologic patterns, emerging pathogens, and improved outcome with antifungal therapy; Walsh TJ et al.; We characterized 27 episodes of fungemia in 22 children infected with the human immunodeficiency virus (HIV) . Fungemia in these patients presented as a community-acquired infection in the setting of outpatient total parenteral nutrition or intravenous antibiotic therapy through a chronically indwelling central venous catheter (CVC) . Fungemia developed only in patients with CVCs (P < .001) . Non-albicans Candida species, Torulopsis glabrata, Rhodotorula rubra, and Bipolaris spicifera constituted 52% of all causes . Fungemia was detected early, within a median of 2.4 days after the onset of new fever, which permitted prompt administration of amphotericin B (mean dosage, 0.7 mg/{kg.day}; median duration, 19 days) . CVCs were removed in 23 (85%) of the episodes . We conclude that fungemia in HIV-infected children often presents as a community-acquired infection, is frequently due to newly emerging opportunistic fungi, and can be managed, with a high level of success (95% survival with no posttherapeutic sequelae), by early diagnosis, prompt initiation of amphotericin B therapy, and removal of the CVC. J Clin Lab Anal, 1995, 9(5), 334 - 9 (1-->3)-beta-D-glucan in culture fluid of fungi activates factor G, a limulus coagulation factor; Miyazaki T et al.; Two well-known polysaccharides, (1-->3)-beta-D-glucan and mannan, are major structural components of the fungus cell wall . The G test is a direct method to measure (1-->3)-beta-D-glucan using a (1-->3)-beta-D-glucan-sensitive component, factor G, fractionated from the limulus lysate . The concentration of (1-->3)-beta-D-glucan in culture supernatants of Candida albicans increased to 1,390.0 pg/ml at 24 hours . The concentration of mannan also increased parallel with fungal growth . However, after digestion of supernatants with endo-(1-->3)-beta-D-glucanase, the reactivity to factor G disappeared, although titers of antimannan monoclonal antibody-based latex agglutination were unchanged . Our study demonstrated that cell suspensions of both C . albicans and Cryptoccocus neoformans activated the limulus factor G, and that not only the conidia form but also the filamentous form of Aspergillus fumigatus reacted with factor G . Various Candida spp . (C . paraspilosis, C . glabrata, C . tropicalis, C . krusei), Saccharomyces cerevisiae, Rhodotorula rubra, Trichosporon beigelii, and A . fumigatus released soluble (1-->3)-beta-D-glucan into their culture supernatants, but C . neoformans and Cunninghamella bertholletiae showed only a small reaction to the G test during their culture . Our results indicate that the G test is a good method for serodiagnosis of deep mycosis and also as a screening tool for contamination of medical devices, drugs, and experimental materials with (1 --> 3)-beta-D-glucan. Cytobios, 1995, 81(327), 201 - 11 Morphogenetic effects induced by spermine and ruthenium red in yeasts; Poli F et al.; Spermine (Sp) produces growth inhibition and wall malformation in Saccharomyces cerevisiae in response to oversynthesis of beta-glucans and chitin . The effect is related to the polycation nature of the molecule . In the present work, to verify this hypothesis, the yeast was treated with the abiogenic polycation ruthenium red (RR) . The strict analogy observed between the RR- and Sp-induced alterations reinforced our earlier assumption that Sp interacted with the anionic sites of the plasmalemma determining a spurious activation of the two inserted enzymes beta-glucan and chitin synthases . This view was further confirmed by the aberrant accumulation of beta-glucans in Schizosaccharomyces pombe and of chitin in Rhodotorula glutinis treated with Sp and RR . In these micro-organisms spermidine, which bears three amino groups instead of the four encountered in Sp, was ineffective . It is inferred that at least four cation sites must be present in a compound in order to affect wall morphogenesis in yeasts. Electrophoresis, 1994 Dec, 15(12), 1559 - 65 Response of bacteria and fungi to high-pressure stress as investigated by two-dimensional polyacrylamide gel electrophoresis; Gross M et al.; In an attempt to generalize previous observations (Jaenicke et al., Appl . Environ . Microbiol . 1988, 54, 2375-2380) and to find a convenient model system for studies of the pressure response, we tested the suitability of Escherichia coli and Thermotoga maritima (bacteria), and of five different eukaryotic species including the filamentous fungi Asteromyces cruciatus and Dendryphiella salina, and the marine yeasts Debaryomyces hansenii, Rhodosporidium sphaerocarpum, and Rhodotorula rubra . Using two-dimensional polyacrylamide gel electrophoresis, detailed investigations on the pressure response were carried out with E . coli and Rhodosporidium sphaerocarpum . In the former organism, major pressure response proteins could not be detected, although there are significant differences in expression of some proteins as well as some minor components that are found in all of the high pressure cell extracts but not in extracts from cultures grown at atmospheric pressure . In Rhodosporidium sphaerocarpum, no change in protein expression patterns was observed between 0.1 and 20 MPa . However, approaching the limit of viability of 50 MPa, additional protein spots became detectable at 45 MPa . This finding correlates with the observation of abnormal growth forms of the organism at this pressure (Lorenz, R . et al . manuscript in preparation). Bone Marrow Transplant, 1994 Oct, 14(4), 647 - 9 Diagnosis of fungemia in bone marrow transplantation patients by examination of peripheral blood smears; Chao TY et al.; Two patients who received BMT for treatment of severe aplastic and AML-M2, developed fungemia during leukopenia . The organisms responsible for the infections were Candida parapsilosis and Rhodotorula glutinis, respectively . Early diagnosis of fungemia in these two patients was made by visualization of fungal blastospores in peripheral blood (PB) smears . These two cases illustrate that cytologic examination of PB smears is a useful method for early detection of fungus infection in BMT patients with leukopenia and unexplained fever in spite of appropriate antibiotic treatment. Biochem Mol Biol Int, 1994 Aug, 33(5), 947 - 55 Chemical modification of lysyl residues of Rhodotorula gracilis D-amino acid oxidase; Gadda G et al.; D-amino acid oxidase from the yeast Rhodotorula gracilis is irreversibly inactivated by reaction with TNBS with complete inactivation accompanied by covalent modification of lysine residues of the protein . The inactivation was biphasic, the fast phase being dependent on TNBS concentration and completed in less than 1 minute . The competitive inhibitor benzoate afforded partial protection against inactivation during the fast phase of the process, with no effect on the slow phase . The pH curve of inactivation (slow phase) indicates the involvement of a residue(s) with a pK of 8.2 . Amino acid analyses showed that in the fast phase of inactivation 1.6 lysine residues were modified, whereas up to 13 lysine residues were modified in the slow phase of inactivation . Our data show that TNBS behaves as an active site-directed reagent in yeast D-amino acid oxidase and they suggest the presence of at least one essential lysyl residue at or near the active site. J Biol Chem, 1994 Jul 8, 269(27), 17809 - 14 Reaction of phenylglyoxal with arginine groups in D-amino-acid oxidase from Rhodotorula gracilis; Gadda G et al.; D-Amino-acid oxidase from Rhodotorula gracilis was irreversibly inactivated by phenylglyoxal in a biphasic process . The fast phase was completed in less than 1 min . Its extent was linearly dependent on phenylglyoxal concentration and was not influenced by the presence of FAD or benzoate, a pseudo-substrate . The second phase of inactivation was due to a simple second-order reaction . The presence of FAD exerted only partial protection; the second-order rate constants of inactivation were 8.3 M-1 min-1 for holoprotein and 18.0 M-1 min-1 for apoprotein . The addition of benzoate completely protected against this second phase of inactivation . Efforts to isolate the enzyme modified at a single arginine residue at the end of the fast phase were unsuccessful, but analysis of the enzyme isolated at the end of the slow phase identified an arginine residue, protected by benzoate, that is highly conserved in all D-amino-acid oxidases and corresponds to Arg283 in the pig kidney enzyme . Modification of this residue is directly involved in the inactivation process during the slow phase . This arginine may represent the basic residue ion pairing with the carboxylate group of the substrate or the residue interacting with the flavin N1-C2 = O locus. Chemotherapy, 1994 Jul-Aug, 40(4), 287 - 9 Rhodotorula spp . fungemia in an immunocompromised boy after neurosurgery successfully treated with miconazole and 5-flucytosine: case report and review of the literature; Marinova I et al.; A case of Rhodotorula fungemia in a 13-year-old boy after neurosurgery successfully treated with miconazole and 5-flucytosine is reported . Intravascular catheter insertion, broad-spectrum anti-miocrobials, surgery, and immunosuppression are the main risk factors for fungemia. J Formos Med Assoc, 1994 Jul, 93(7), 645 - 7 Rhodotorula septicemia: report of a case; Sheu MJ et al.; With the increased use of central venous catheters in cancer patients, there has been an increase in the recovery of environmental and skin organisms from blood cultures . A red yeast, Rhodotorula, an infrequent cause of infection in humans, was isolated from a patient with acute myeloblastic leukemia undergoing bone marrow transplant while he received parenteral nutritional fluids by an indwelling catheter . The patient was clinically ill, as manifested by fever and chills . The patient was treated with amphotericin B and the catheter was removed . He survived the fungemic episode with no recurrence of fungal infection. Biochem Biophys Res Commun, 1994 Jun 15, 201(2), 516 - 22 Reconstitution of the isobutene-forming reaction catalyzed by cytochrome P450 and P450 reductase from Rhodotorula minuta: decarboxylation with the formation of isobutene; Fukuda H et al.; An isobutene-forming activity was reconstituted with cytochrome P450rm and cytochrome P450 reductase purified from Rhodotorula minuta . The nonionic detergent . Emulgen 911, present in the preparation of purified P450rm, inhibited the reconstitution . Bovine serum albumin enhanced the activity of the reconstituted system . Branching of the beta carbon of the substrate carboxylic acid was important for formation of isobutene . In a comparative study with isovalerate and 3-deuterio-3-methylbutanoate, a very large isotopic effect (kH/kD = 14) was observed . This result indicates that formation of isobutene might be initiated by abstraction of hydrogen from the beta carbon of isovalerate and might be followed by decarboxylation. Carbohydr Res, 1994 May 20, 258, 255 - 66 Enzymic synthesis of alpha- and beta-D-glucosides of 1-deoxynojirimycin and their glycosidase inhibitory activities; Asano N et al.; 1-Deoxynojirimycin (1) is a potent inhibitor of mammalian and rice alpha-glucosidase . Several glucosides of 1 were synthesized by use of the native and immobilized enzyme and their effect on various enzymes was investigated . Transglucosylation reactions using rice alpha-glucosidase, yeast alpha- and beta-glucosidases purified from Rhodotorula lactosa were performed with maltose or cellobiose as a glucose donor and N-(benzyloxycarbonyl)-1-deoxynojirimycin (2) as an acceptor . The transglucosylation reaction using native rice alpha-glucosidase afforded 3-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (4), 4-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (5), and 2-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (3) in yields of 40, 13, and 2%, respectively, after 30 min . The transglucosylation reaction using immobilized rice alpha-glucosidase was similar to that using the native enzyme . In the system using native yeast alpha-glucosidase, 3, 5, and 4 were formed in yields of 34, 13, and 6%, respectively, after 15 h . The immobilization of yeast alpha-glucosidase caused a significant decrease in transglucosylation activity . Yeast beta-glucosidase showed a high transglucosylation activity and incubation with the reaction system afforded 2-O-beta-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (6) and 4-O-beta-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (7) in yields of 69 and 3%, respectively, after 3 h . The transglucosylation reaction using immobilized yeast beta-glucosidase preferentially afforded 6 in a yield of 73% after 3 h . After removal of N-benzyloxycarbonyl group from the product glucosides, their glycosidase inhibitory activities were measured . 3-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (9) retained the potent inhibition of 1 against rat intestinal sucrase activity and was more effective than 1 against rice alpha-glucosidase . 4-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (10) retained the potency of 1 against rat intestinal sucrase and isomaltase . 2-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (8) was more effective than 1 against trehalases. Wei Sheng Wu Xue Bao, 1994 Apr, 34(2), 137 - 42 {Studies on the induction of L-phenylalanine ammonia lyase(PAL) in Rhodotorula glutinis and transformation of phenylalanine from trans-cinnamic acid}; Ding X et al.; The induction of PAL in Rhodotorula glutinis and transformation of L-phenylalanine from trans-cinnamic acid were studied . The optimum medium for PAL induction was composed of (g/L) 10.0 yeast extract, 10.0 peptone, 5.0 NaCl, 0.5 KH2 PO4, 0.5 phenylalanine 1.0 (NH4)2SO4 and 5.0 glucose, pH 6.0-6.5 . The cultivation temperature was 30.0 degrees C . In the process of transformation, the effect of {NH4}+ on initial velocity was in accordance with Michaelis-Menten rate expression in which Km and Vmax were 16.85 mol/L and 5.96 g.L-1.h-1 for ammonia and the optimum pH was 10.0 . Substrate activation and inhibition were observed at low and high concentration of cinnamic acid . The yield of phenylalanine from cinnamic acid reached more than 60.0%. Experientia, 1994 Feb 15, 50(2), 130 - 3 Relevance of chlorine-substituent for the antifungal activity of syringomycin and syringotoxin, metabolites of the phytopathogenic bacterium Pseudomonas syringae pv . syringae; Grgurina I et al.; Structural analogues of syringomycin and syringotoxin were produced by fermentation, characterized by FAB-MS and amino acid analysis and compared to the parent compounds in the antibiosis test against Rhodotorula pilimanae . The C-terminal residue was shown to be important for the activity. Biochem J, 1994 Feb 1, 297 ( Pt 3), 647 - 52 Substrate analogues as probes of the catalytic mechanism of L-mandelate dehydrogenase from Rhodotorula graminis; Smekal O et al.; A detailed kinetic analysis of the oxidation of mono-substituted mandelates catalysed by L-(+)-mandelate dehydrogenase (L-MDH) from Rhodotorula graminis has been carried out to elucidate the role of the substrate in the catalytic mechanism . Values of Km and kcat . (25 degrees C, pH 7.5) were determined for mandelate and eight substrate analogues . Values of the activation parameters, delta H++ and delta S++ (determined over the range 5-37 degrees C), for mandelate and all substrate analogues were compensatory resulting in similar low values for free energies of activation delta G++ (approx . 60 kJ.mol-1 at 298.15 K) in all cases . A kinetic-isotope-effect value of 1.1 +/- 0.1 was observed using D,L-{2-2H}mandelate as substrate and was invariant over the temperature range studied . The logarithm of kcat . values for the enzymic oxidation of mandelate and all substrate analogues (except 4-hydroxymandelate) showed good correlation with Taft's dual substituent constant omega (where omega = omega I + 0.64 omega +R) and gave a positive reaction constant value, rho, of 0.36 +/- 0.07 . This linear free-energy relationship was verified by analysing the data using isokinetic methods . These findings support the hypothesis that the enzyme-catalysed reaction proceeds via the same transition state for each substrate and indicates that this transition state is relatively nonpolar but has an electron-rich centre at the alpha-carbon position. Folia Microbiol (Praha), 1994, 39(4), 265 - 8 The influence of pH on growth kinetics of yeasts in the presence of benzoate as a sole carbon source; Muncnerova D et al.; The inhibitory effect and substrate properties of benzoic acid were estimated for 25 yeast strains belonging to genera Candida, Hansenula, Hypopichia, Rhodosporidium, Rhodotorula, Saitoella and Trichosporon . Benzoic acid can serve as a sole carbon source for growth of yeasts belong to genera Rhodotorula, Rhodosporidium and Saitoella in synthetic mineral media . Specific growth rate is strongly dependent both on the concentration of benzoate and the pH value of the cultivation media . Maximum specific growth rate on benzoate is observed in alkaline cultivation media at pH 7.0-7.5 whereas those for growth on glucose in mildly acidic media at pH 5.0 . Some of the strains showed weak growth on benzoate even at pH 8.5 . Some carotenoid-containing yeasts of the genera Rhodotorula and Rhodosporidium lost their ability to synthesize carotenoid pigments during growth in alkaline benzoate media. Biochemistry, 1993 Dec 21, 32(50), 14023 - 33 A non-heme iron protein with heme tendencies: an investigation of the substrate specificity of thymine hydroxylase; Thornburg LD et al.; Thymine hydroxylase from Rhodotorula glutinis catalyzes the oxidation of thymine to its alcohol, aldehyde, and carboxylic acid in three successive reactions . Each step involves stoichiometric consumption of O2 and alpha-ketoglutarate and formation of CO2 and succinate . Given the promiscuity of this enzyme, it was hoped that it would serve as a prototype for understanding the mechanism of this class of enzymes, the non-heme Fe2+ dioxygenases . Kinetic parameters for thymine, O2, Fe2+, and alpha-ketoglutarate have been determined, and isotope effect analysis of (trideuteriomethyl)thymine with enzyme reveals D(V) = 2.08 and D(V/K) = 1.11 at saturating O2 . The kinetic parameters for (hydroxymethyl)uracil oxidation have been determined, and incubation of (5'-R)- and (5'-S)-{5'-2H}-5-(hydroxymethyl)uracil with enzyme reveals stereospecific removal of the pro-S hydrogen . No apparent isotope effect is observed in this reaction . The substrate specificity of this enzyme has been examined in detail . The enzyme can catalyze epoxidation, oxidation of a thioether to a sulfoxide and a sulfone, hydroxylation of an unactivated carbon-hydrogen bond, and oxidation of a methylamine to formaldehyde, as revealed through studies with 5-vinyluracil, 5-(methylthio)uracil, 5,6-dihydrothymine, and 1-methylthymine, respectively . In each case, the products were identified by gas chromatography-mass spectrometry, and 18O2-labeling studies revealed that one atom from O2 is incorporated into each product . The enzyme has also been shown to catalyze an uncoupling of hydroxylation and decarboxylation in the presence of a substrate analog incapable of undergoing hydroxylation or a substrate that is difficult to oxidize.(ABSTRACT TRUNCATED AT 250 WORDS) Can J Microbiol, 1993 Dec, 39(12), 1135 - 41 The expression of potential colonization factors of yeasts isolated from fish during different growth conditions; Vazquez-Juarez R et al.; Three strains, Rhodotorula rubra, Rhodotorula glutinis, and Candida zeylanoides, isolated from fish, were tested for the expression of putative tissue colonization factors . All strains were able to bind collagen type I, fibronectin, and laminin to various degrees after growing on various solid and broth media, while the binding to collagen type IV was sparse under all conditions tested . For the three strains tested, a very low cell surface hydrophobicity was shown for growth on various solid and broth media . Mostly, the strains also expressed a negatively charged surface . Extracellular protease activity using different substrates was shown for all three strains . Furthermore, two properties related to iron scavenging, i.e., binding of lactoferrin and production of siderophores, were also tested . For the three strains a capacity to bind lactoferrin as well as a capacity to excrete siderophores were demonstrated . Since these different properties have been correlated to virulence and to the capacity of colonization in other organisms, we address the question of whether the expression of these properties in yeasts could contribute to colonization in fish. FEMS Microbiol Lett, 1993 Nov 15, 114(1), 73 - 7 Sulfonate-sulfur assimilation by yeasts resembles that of bacteria; Uria-Nickelsen MR et al.; Three sulfonates were tested for their ability to serve as nutrients for Hansenula wingei, Rhodotorula glutinis, Trigonopsis variabilis and Saccharomyces cerevisiae . Cysteate, taurine and isethionate, under aerobic conditions, could be utilized as sources of sulfur, although in some instances final cell yields were less than those obtained with an equimolar amount of sulfate-sulfur . Sulfonate assimilation by S . cerevisiae resembled that of bacteria (reported earlier by us) in several aspects: first, sulfate-S was used in preference to that of sulfonate, when both were present; second, mutants unable to use sulfate as a source of sulfur because of deficiencies in ATP sulfurylase, adenylylsulfate kinase (APS kinase) or PAPS reductase were able to utilize sulfonates; and third, mutants deficient in sulfite reductase were unable to utilize sulfonates. J Biol Chem, 1993 Nov 15, 268(32), 23954 - 8 Mechanisms of ferulic acid conversions to vanillic acid and guaiacol by Rhodotorula rubra; Huang Z et al.; Resting cells of Rhodotorula rubra converted transferulic acid (1) to vanillic acid (2), then to guaiacol (3) and protocatechuic acid (4), under aerobic conditions . In an argon atmosphere, R . rubra transformed ferulic acid to vanillic acid and 4-hydroxy-3-methoxystyrene (5) . Metabolites were isolated by solid-phase extraction and characterized by mass spectrometry, 1H, and 13C-nuclear magnetic resonance spectroscopy (NMR) . The biotransformation of ferulic acid to vanillic acid by R . rubra cell-free extracts required CoA, ATP, and NAD+ . Mass spectrometry and 13C-NMR were used to demonstrate the incorporation of oxygen from H2(18)O during the conversion of ferulic acid to vanillic acid . The results suggest a parallel between this bioconversion reaction and the beta-oxidation of fatty acids . Proton-carbon correlation NMR spectroscopy was used to demonstrate the specific incorporation of deuterium from D2O into guaiacol obtained from vanillic acid . The incorporation of deuterium implicates the involvement of a quinoid vanillic acid tautomer as an intermediate in the decarboxylation reaction. Zhonghua Min Guo Xiao Er Ke Yi Xue Hui Za Zhi, 1993 Nov-Dec, 34(6), 436 - 42 Fungal esophagitis in children; Young C et al.; Seven patients were endoscopically diagnosed as having a fungal esophagitis with mycologic or histologic support for the diagnosis from 1979 to 1991 in the Department of Pediatrics, National Taiwan University Hospital . The major causative agent was Candida albicans . Other fungi isolated were Candida Krusei, Trichosporon cutaneum, Trichosporon beigelii, and Rhodotorula rubra, but they all resembled one another under endoscopic examination . The most common presenting symptom was hematemesis, and the lower part of the esophagus was more often involved . Only one patient was documented to have oral thrush . Most of the children did not present typical symptoms of esophagitis such as dysphagia or odynophagia, and they tended to be in more advanced stages of the disease when the diagnosis was made. J Mol Biol, 1993 Oct 20, 233(4), 781 - 3 Preliminary crystallographic study of D(-)-mandelate dehydrogenase from Rhodotorula graminis; Basak AK et al.; NAD+ dependent D(-)-mandelate dehydrogenase from the yeast Rhodotorula graminis strain KGX 39 has been crystallized in three different forms using the hanging drop vapour diffusion method at 15 to 20 degrees C . Type I crystals belong to space group P222(1), P22(1)2(1) or P2(1)2(1)2(1) with a = 100.3 A, b = 117.4 A, c = 80.4 A and are likely to contain a dimer in the crystallographic asymmetric unit . They diffract to dmin = 3.0 A . Type II crystals belong to space group P22(1)2(1) or P2(1)2(1)2(1) with a = 187.8 A, b = 122.9 A, c = 72.1 A and contain probably two dimers in the crystallographic asymmetric unit . They diffract to dmin = 1.8 A . Type III crystals belong to space group P2(1)2(1)2(1) with a = 109.6, b = 52.0 A, c = 145.7 A, and are likely to contain a dimer in the crystallographic asymmetric unit . They diffract at least to dmin = 2.5 A. Antibiot Khimioter, 1993 Oct-Nov, 38(10-11), 16 - 9 {The effect of lovastatin on sterol synthesis and yeast resistance to polyene antibiotics}; Kreiner VG et al.; Lovastatin (monocolin K) is a competitive inhibitor of 3-hydroxy-3-methylglutaryl-CoA-reductase . Its influence on the growth of a lovastatin sensitive strain of Rhodotorula rubra, the biosynthesis of ergosterol and the resistance to polyenic antibiotics was studied . It was shown that the lovastatin action on the strain depended on the inhibitor dose . In a concentration of 0.1 to 0.5 micrograms/ml lovastatin inhibited the yeast growth and ergosterol biosynthesis . Higher concentrations of the inhibitor in the medium led to the recovery of the sterol biosynthesis . It was also demonstrated that a decrease of the ergosterol level in the cells under the influence of lovastatin resulted in the development of resistance in the yeast to polyenic antibiotics such as nistatin and amphotericin B . Correlation between the ergosterol level in the yeast cells and their susceptibility to the polyenic antibiotics was observed. J Clin Microbiol, 1993 Sep, 31(9), 2489 - 90 New cause for false-positive results with the Pastorex Aspergillus antigen latex agglutination test; Kappe R et al.; The Pastorex Aspergillus antigen test for detection of Aspergillus galactomannan antigen in the sera of patients with invasive aspergillosis is used in many clinical laboratories . A serum sample contaminated with Penicillium chrysogenum gave a strongly positive reaction (1:128) which was heat stable, was not eliminated by pronase treatment, and was not detected by a normal rabbit globulin control . This observation was shown to be due to cross-reactions of the monoclonal antibody EB-A2 used by the kit with several airborne fungi likely to contaminate serum samples, including Penicillium chrysogenum, Cladosporium herbarum, Acremonium species, Alternaria alternata, Fusarium oxysporum, Wangiella dermatitidis, and Rhodotorula rubra. Mol Cell Biol, 1993 Sep, 13(9), 5613 - 9 An mRNA-type intron is present in the Rhodotorula hasegawae U2 small nuclear RNA gene; Takahashi Y et al.; Splicing an mRNA precursor requires multiple factors involving five small nuclear RNA (snRNA) species called U1, U2, U4, U5, and U6 . The presence of mRNA-type introns in the U6 snRNA genes of some yeasts led to the hypothesis that U6 snRNA may play a catalytic role in pre-mRNA splicing and that the U6 introns occurred through reverse splicing of an intron from an mRNA precursor into a catalytic site of U6 snRNA . We characterized the U2 snRNA gene of the yeast Rhodotorula hasegawae, which has four mRNA-type introns in the U6 snRNA gene, and found an mRNA-type intron of 60 bp . The intron of the U2 snRNA gene is present in the highly conserved region immediately downstream of the branch site recognition domain . Interestingly, we found that this region can form a novel base pairing with U6 snRNA . We discuss the possible implications of these findings for the mechanisms of intron acquisition and for the role of U2 snRNA in pre-mRNA splicing. Biosci Biotechnol Biochem, 1993 Sep, 57(9), 1599 - 601 Purification and characterization of cytochrome P450 from an isobutene-forming microorganism, Rhodotorula minuta; Fukuda H et al.; A cytochrome P450 was purified from microsomes of Rhodotorula minuta . The optical spectrum of the purified cytochrome was characteristic of a low-spin ferric heme protein . Isovalerate caused a type I spectral change in it . The amino-terminal sequence of the cytochrome was different from those of other known microsomal cytochrome P450s . These results indicate that the cytochrome, which is tentatively named P450rm, is a novel species of cytochrome P450. J Steroid Biochem Mol Biol, 1993 Aug, 46(2), 259 - 63 Biotransformation--XXXIV . Metabolism of testosterone esters in fungi cultures; Brzezowska E et al.; Seven esters of testosterone: acetate, propionate, enanthate, caprate, undecanoate, isobutyrate and isocaproate (some of them are used as drugs) were transformed by microorganisms: Absidia coerulea, Acremonium roseum, Aphanocladium album and Rhodotorula mucilaginosa to obtain some information about their metabolism . It was observed that the presence and structure of the acyl group mainly influenced the degree of transformation . The first step of the reaction was probably hydrolysis of ester, followed by testosterone transformation . Only the branched chain esters were transformed by R . mucilaginosa without hydrolysis of the ester bond. Biochem J, 1993 Jul 15, 293 ( Pt 2), 455 - 60 L(+)-Mandelate dehydrogenase from Rhodotorula graminis: purification, partial characterization and identification as a flavocytochrome b; Yasin M et al.; L(+)-Mandelate dehydrogenase was purified to homogeneity from the yeast Rhodotorula graminis KGX 39 by a combination of (NH4)2SO4 fractionation, ion-exchange and hydrophobic-interaction chromatography and gel filtration . The amino-acid composition and the N-terminal sequence of the enzyme were determined . Comprehensive details of the sequence determinations have been deposited as Supplementary Publication SUP 50172 (4 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem . J . (1993) 289, 9 . The enzyme is a tetramer as judged by comparison of its subunit M(r) value of 59,100 and native M(r) of 239,900, estimated by SDS/PAGE and gel filtration respectively . There is one molecule of haem and approx . one molecule of non-covalently bound FMN per subunit . 2,6-Dichloroindophenol, cytochrome c and ferricyanide can all serve as electron acceptors . L(+)-Mandelate dehydrogenase is stereospecific for its substrate . D(-)-Mandelate and L(+)-hexahydromandelate are competitive inhibitors . The enzyme has maximum activity at pH 7.9 and it has a pI value of 4.4 . HgCl2 and 4-chloromercuribenzoate are potent inhibitors, but there is no evidence that the enzyme is subject to feedback inhibition by potential metabolic effectors . The evidence suggests that L(+)-mandelate dehydrogenase from R . graminis is a flavocytochrome b which is very similar to, and probably (at least so far as the haem domain is concerned) homologous with, certain well-characterized yeast L(+)-lactate dehydrogenases, and that the chief difference between them is their mutually exclusive substrate specificities. J Biol Chem, 1993 Jul 5, 268(19), 13850 - 7 Kinetic mechanism of D-amino acid oxidases from Rhodotorula gracilis and Trigonopsis variabilis; Pollegioni L et al.; The reaction of two D-amino acid oxidases from the yeasts Rhodotorula gracilis and Trigonopsis variabilis with the substrates alanine and valine in their 2-1H and 2-2H forms was studied employing the stopped-flow spectrophotometric technique . The turnover numbers at infinite substrate and oxygen concentrations were: 20,700/4,250 and 1,730/360 ({2-1H}/{2-2H}alanine and valine, respectively) for the Rhodotorula and 3,150/440 and 2,500/520 ({2-1H}/{2-2H}alanine and valine, respectively) for the Trigonopsis enzymes . The rates of anaerobic enzyme flavin reduction were 20,100/4,000 and 1,820/350 ({2-1H}/{2-2H}alanine and valine, respectively) for the Rhodotorula and 3,470/350 and 2,460/480 ({2-1H}/{2-2H}alanine and valine, respectively) for the Trigonopsis enzymes . The isotope effects on enzyme reduction were 5.0 and 5.2 for Rhodotorula and 9.9 and 5.1 for Trigonopsis D-amino acid oxidases with alanine and valine, respectively . This suggests that the intrinsic isotope effect on rupture of the substrate alpha-C-H bond can be as high as 10 . The rate-determining step corresponds to the enzyme reductive half-reaction in contrast to the mammalian kidney enzyme where it is the product release from oxidized enzyme (Massey, V., and Gibson, Q.H . (1964) Fed . Proc . 23, 18-29) . Upon anaerobic reaction with substrate, the yeast enzymes do not form the transient long wavelength absorbing species which are characteristic of the mammalian protein . This is due only in part to rapid dissociation of iminoacid product and is ascribed to intrinsic differences between the charge-transfer complexes of reduced enzyme flavin and product of the yeast as compared to the mammalian enzyme . With the Trigonopsis enzyme the flavin radical anion appears to be strongly stabilized and can be produced quantitatively. J Gen Microbiol, 1993 Jun, 139 ( Pt 6), 1345 - 52 Relationships amongst some bacterial and yeast lactate and mandelate dehydrogenases; Fewson CA et al.; Five yeast strains were isolated by enrichment culture on the basis of their ability to grow on mandelate and two of these strains were identified as Rhodotorula glutinis . In addition, a range of yeasts from culture collections was screened for growth on mandelate . The results suggest that mandelate utilization is a widespread but not universal characteristic within the genus Rhodotorula . Several of the yeasts contained an inducible NAD-dependent D(-)-mandelate dehydrogenase and an inducible dye-linked (presumably flavoprotein) L(+)-mandelate dehydrogenase . All the D(-)-mandelate dehydrogenases from the yeasts showed immunological cross-reactivity with each other (as judged by both immunoinhibition and immunoblotting), as did all the yeast L(+)-mandelate dehydrogenases that were tested . Determination of N-terminal amino acid sequences of several bacterial and yeast lactate and mandelate dehydrogenases, together with the evidence from the immunological studies, confirmed and extended previous proposals that there are several major groups of such dehydrogenases: FMN-dependent, membrane-bound L(+)-lactate and L(+)-mandelate dehydrogenases (M(r) = approx . 44,000) in bacteria, mitochondrial flavocytochrome b2 L(+)-lactate and L(+)-mandelate dehydrogenases (M(r) = approx . 59,000) in yeasts, FAD-dependent, membrane-bound D(-)-lactate and D(-)-mandelate dehydrogenases in bacteria, and soluble NAD-dependent D(-)-mandelate dehydrogenases in both bacteria and yeasts. Allergy, 1993 May, 48(4), 298 - 9 Extrinsic allergic alveolitis after exposure to the yeast Rhodotorula rubra; Siersted HC et al.; A case of extrinsic allergic alveolitis following exposure to the red yeast Rhodotorula rubra is reported--to our knowledge, for the first time . Extensive growth of the yeast in the patient's environment was demonstrated, explaining an elevated titer of Rhodotorula-specific precipitating antibodies in his serum . A bronchial provocation test confirmed the diagnosis. Biochem J, 1993 Feb 15, 290 ( Pt 1), 103 - 7 L-mandelate dehydrogenase from Rhodotorula graminis: comparisons with the L-lactate dehydrogenase (flavocytochrome b2) from Saccharomyces cerevisiae; Smekal O et al.; L-Lactate dehydrogenase (L-LDH) from Saccharomyces cerevisiae and L-mandelate dehydrogenase (L-MDH) from Rhodotorula graminis are both flavocytochromes b2 . The kinetic properties of these enzymes have been compared using steady-state kinetic methods . The most striking difference between the two enzymes is found by comparing their substrate specificities . L-LDH and L-MDH have mutually exclusive primary substrates, i.e . the substrate for one enzyme is a potent competitive inhibitor for the other . Molecular-modelling studies on the known three-dimensional structure of S . cerevisiae L-LDH suggest that this enzyme is unable to catalyse the oxidation of L-mandelate because productive binding is impeded by steric interference, particularly between the side chain of Leu-230 and the phenyl ring of mandelate . Another major difference between L-LDH and L-MDH lies in the rate-determining step . For S . cerevisiae L-LDH, the major rate-determining step is proton abstraction at C-2 of lactate, as previously shown by the 2H kinetic-isotope effect . However, in R . graminis L-MDH the kinetic-isotope effect seen with DL-{2-2H}mandelate is only 1.1 +/- 0.1, clearly showing that proton abstraction at C-2 of mandelate is not rate-limiting . The fact that the rate-determining step is different indicates that the transition states in each of these enzymes must also be different. Med Dosw Mikrobiol, 1993, 45(3), 389 - 92 {Characteristics of fungi and attempts of their elimination from the oral cavity in children treated with orthodontic appliances}; Bialasiewicz D et al.; Microbiological evaluation of oral cavity was performed in 112 children, aged 6-18 years, with retrogenic defects (group I) and other defects (group II) . The material for microbiological investigation consisted of contents of oral cavity cultured on the Sabouraud broth . Isolated abacterial strains of fungi were differentiated according to their morphological and biochemical properties . Among isolated fungi, independently of the bite defects and age of children, highest percentage of strains of Candida albicans was noted . Remaining species represented genus Candida (C . glabrata, C . guilliermondii, C . krusei, C . parapsilosis, C . pseudotropicalis, C . zeylanoides), Geotrichum (G . candidum), Rhodotorula (R . rubra) and Trichosporon (T . cutaneum) . Fungi were present in oral cavity in 45% (age 6-8 years) and 36.4% (age 9-18 years) of group I patients . In group II these percentages were respectively 15.2 and 58.7 . In control groups occurrence of fungi was 3-4 times lower . Despite application of disinfectants and treatment with nystatin, frequency of isolation of fungi did not change. Folia Microbiol (Praha), 1993, 38(6), 467 - 72 Effects of the physiological state of five yeast species on H(+)-ATPase-related processes; Kotyk A et al.; Effects of starvation and glucose preincubation on membrane potential, ATPase-mediated acidification and glutamic acid transport were studied in yeast species Saccharomyces cerevisiae, Schizosaccharomyces pombe, Dipodascus magnusii, Lodderomyces elongisporus and Rhodotorula gracilis . The membrane potential was highest after preincubation with glucose in all species but L . elongisporus and R . gracilis . In all cases the membranes were depolarized in the presence of 20 mmol/L KCl and hyperpolarized with 50 mumol/L diethylstilbestrol (DES) . The extracellular acidification caused by addition of glucose was highest after preincubation with glucose in all cases except in R . gracilis where there was none . In all cases except in R . gracilis addition of KCl caused a marked increase in the acidification rate . Addition of DES with glucose caused a large decrease in rate in S . cerevisiae but had much less effect on the other species . Transport of glutamic acid was clearly increased after pretreatment with glucose in S . cerevisiae, S . pombe and D . magnusii (mainly due to enhanced synthesis of the carrier) but actually decreased in R . gracilis and L . elongisporus . Addition of DES had an inhibitory effect in all species but much more pronounced in S . cerevisiae and S . pombe than in others . In general, both the acidification and the transport of glutamate were enhanced after preincubation with glucose but much more so in the semianaerobic species, such as S . cerevisiae, than in the strict aerobes (R . gracilis) where the effect was occasionally negative . There was no relationship between the ATPase-mediated acidification and the membrane potential. Biochem Int, 1992 Dec, 28(4), 693 - 700 Characterization of trehalase in Rhodotorula rubra; Mansure JJ et al.; Trehalase activity in Rhodotorula rubra was found to be bound to the particulate fraction of a cell-free extract in contrast with the soluble trehalase activity of Saccharomyces cerevisiae . The enzyme was strongly repressed by glucose and derepressed during growth on maltose, trehalose and glycerol . This increase in activity was due to a "de novo" synthesis as seen by inhibition with cycloheximide, a mechanism not described for Saccharomyces cerevisiae . Catabolite inactivation by addition of glucose was also demonstrated . This particulate enzyme does not respond to activation by the cAMP-dependent protein kinase. Biochem Int, 1992 Dec, 28(6), 1089 - 96 Role of alkaline metal ions in the H(+)-ATPase activity of various yeast species; Kotyk A et al.; Saccharomyces cerevisiae, Schizosaccharomyces pombe, Endomyces magnussi, Lodderomyces elongisporus and Rhodotorula gracilis, yeast species ranging from a glycolytic type to a strictly aerobic one, were tested for the activity of their plasma membrane H(+)-ATPase and the effect of alkaline metal cations thereon . The ATP-hydrolyzing activity of membranes from glucose-activated cells ranged from 456 to 932 mumol inorganic phosphate released per min per 1 g membrane protein . The effect of 0.2 M Li+, Na+, K+, Rb+ and Cs+ never exceeded the statistical range of error . In contrast, acidification after glucose addition ranged from 0.15 (for R . gracilis) to 14.8 nmol H+ per min per mg dry weight (for S . cerevisiae) and it was markedly influenced by the presence of alkaline metal chlorides, the highest effect observed being a seven-fold increase by K+ in a S . cerevisiae suspension . The effects were additive to those observed without ions in solution and are ascribed to the operation of independent channels and/or exchange systems for H+ with a clear selectivity toward K+ . The separate nature of the ion-triggered extracellular acidification is supported by a different ratio of titration to pH-derived acidity with and without K+. Chest, 1992 Nov, 102(5), 1516 - 9 Rhodotorula rubra contamination in fiberoptic bronchoscopy; Whitlock WL et al.; Rhodotorula rubra was recovered in 18 bronchoscopic specimens from 15 patients from May to November 1987 . One hundred and twenty-one bronchoscopies were performed during that period by two bronchoscopists (W . W.; R.D.) at Letterman Army Medical Center in San Francisco . Isolation of R rubra occurred in 11 bronchoalveolar lavage (BAL) specimens, four bronchial washes, and three transbronchial biopsies . Clinical infection was not present in any of these patients, although five were immunocompromised hosts . After a stepwise infection control review of the laboratory, the bronchoscopy suite, bronchoscopists, and the fiberoptic bronchoscope failed to recover the organism, a systematic evaluation of the cleaning procedure was undertaken . We discovered that replacement of the suction valve and the rubber biopsy valve on the biopsy channel immediately after cleaning allowed moisture to accumulate in these areas . Removal of both the suction valve and biopsy valve during periods of nonuse resulted in adequate drying of the biopsy channel and eradication of contamination from December 1987 to May 1990 (350 bronchoscopies) . Epidemiologic and infection control surveillance is critical for bronchoscopy, especially when possible pathogens are recovered by BAL in the immunocompromised patient. Mycoses, 1992 Nov-Dec, 35(11-12), 305 - 8 Rhodotorula fungaemia: a life-threatening complication of indwelling central venous catheters; Braun DK et al.; A 30-year-old woman receiving total parenteral nutrition via an indwelling central venous catheter for an intestinal motility disorder developed fever, tachycardia, tachypnea, and hypotension . Multiple blood cultures drawn through the catheter prior to these events, as well as a peripheral blood culture obtained earlier, grew the red yeast Rhodotorula rubra . The patient was critically ill for over one month but eventually recovered with therapy including the systemic antifungal agents amphotericin B and flucytosine and removal of the catheter . Although Rhodotorula has generally been regarded as having low pathogenicity, this case emphasizes the serious nature of Rhodotorula sepsis and suggests the need for both systemic antifungal therapy and removal of a colonized indwelling catheter. Biochem J, 1992 Sep 1, 286 ( Pt 2), 389 - 94 Studies on the active centre of Rhodotorula gracilis D-amino acid oxidase and comparison with pig kidney enzyme; Pollegioni L et al.; D-Amino acid oxidase (EC 1.4.3.3) from Rhodotorula gracilis has been reconstituted with 8-chloro-, 8-mercapto-, 6-hydroxy-, 2-thio-, 5-deaza- and 1-deaza-FAD, and the properties of the resulting complexes have been studied and compared with those of the correspondingly modified pig kidney D-amino acid oxidases . Binding appears to be tight for most analogues, at least as tight as for native FAD (approximately 10(-8) M) . 8-Mercapto- and 6-hydroxy-FAD bind in their para- and ortho-quinoid forms respectively to yeast D-amino acid oxidase, inferring the presence of a positive charge near the flavin N(1) position, as in the case of the mammalian enzyme . On the other hand, important differences in active-site microenvironment emerge: solvent accessibility to flavin position 8 is drastically restricted in yeast D-amino acid oxidase as indicated by the unreactivity of 8-chloro- and 8-mercapto-FAD enzyme with thiolates and alkylating agents . Significantly different microenvironments are also likely to occur around the flavin positions N(1)-C(2) = 0, N(3)-H and N(5) . This is deduced from the differences in interaction of the two proteins with 1-deaza-FAD, 5-deaza-FAD and 2-thio-FAD and from the properties of the respective complexes . The same re-side flavin stereospecificity as shown by the mammalian enzyme was determined for the yeast enzyme using 8-hydroxy-5-deaza-FAD . Thus we can deduce the presence of a similar pattern of functional groups at the active centres of the two enzymes, while the fine tuning of specificity and regulation correlate with environmental differences at specific flavin loci. Mycoses, 1992 Sep-Oct, 35(9-10), 229 - 34 Vaginal yeast flora of pregnant women in the Cusco region of Peru; Vidotto V et al.; A study of the vaginal yeast flora in pregnant women living in Cusco and in its region (Peru), located approximately 3000 m above sea level, is reported . We observed 300 pregnant, healthy and non-diabetic women who attended a gynaecological clinic in the Lorena, Regional or IPSS (Instituto Peruano de Seguridad Social) hospitals in Cusco . A comprehensive clinical history was obtained from each patient . It included age, work, parity, time of pregnancy, use of contraceptives or antibiotics, type of vaginal symptoms, type and amount of vaginal secretion . The yeasts were isolated from 44.3% of the cases . The positive cases were more frequently found in the following categories: 20-30 year-old patients (69.2%), ninth month of pregnancy (49.6%), first pregnancy (41.4%), no delivery (58.7%) and no abortion (66.9%) . Most women complained of leukorrhea (75.9%) with mucus, scarce without odour (18.8%) or lumpy, regular, without odour (15.8%) secretion . The yeasts isolated were Candida albicans (66.2%), other Candida species (12.8%), Torulopsis glabrata (8.3%) or other Torulopsis species (2.2%), Saccharomyces cerevisiae (7.5%), Rhodotorula sp . (1.5%) and Trichosporon cutaneum (1.5%). Chem Pharm Bull (Tokyo), 1992 Jul, 40(7), 1871 - 5 Enzymatic synthesis of glucoside derivatives of validamine and valienamine; Furumoto T et al.; alpha- And beta-glucoside derivatives of validamine and valienamine were prepared by enzymatic transglucosidation using alpha- and beta-glucosidase of Rhodotorula lactosa . The structures of these derivatives have been elucidated by 13C- and 1H-nuclear magnetic resonance spectral analysis . Thus, 7-alpha-glucoside, 7-alpha-isomaltoside, and 4-alpha-glucoside of validamine and 7-alpha-glucoside, 7-alpha-isomaltoside, 4-alpha-glucoside, and 4-alpha-isomaltoside of valienamine were obtained from maltose and validamine or valienamine using alpha-glucosidase . 7-beta-glucoside, 2-beta-glucoside, and 4-beta-glucoside of validamine or valienamine were obtained from cellobiose and validamine or valienamine using beta-glucosidase . These derivatives were tested for alpha-glucosidase inhibitory activity on rat small intestinal glycosidases. Clin Infect Dis, 1992 Apr, 14(4), 841 - 6 Sepsis due to Rhodotorula related to use of indwelling central venous catheters; Kiehn TE et al.; With increased use of surgically implanted silastic central venous catheters, there has been an increase in the recovery from blood cultures at Memorial Sloan-Kettering Cancer Center (New York) of environmental and skin organisms including the red yeast Rhodotorula . From 1985 through 1989, 23 patients had catheter-related Rhodotorula sepsis . All 23 patients had indwelling central venous catheters that had been in place from 1 to 22 months (average, 9.3 months) prior to the detection of fungemia . All patients had blood drawn both through the catheter and from a peripheral source, and only one patient had a peripheral blood culture positive for Rhodotorula . Colony counts of yeast from the catheter cultures often exceeded 100 (15 patients) and even 1,000 (seven patients) cfu/mL of blood . Thirteen of the patients were treated with antifungal therapy and had the catheter removed, and five patients received antifungal therapy without catheter removal (suggesting that compulsory removal of the catheter may not always be required) . Five patients had the catheter removed without antifungal therapy . All patients survived the fungemic episode and experienced no recurrence of the infection. Protein Expr Purif, 1992 Apr, 3(2), 165 - 7 Purification of Rhodotorula gracilis D-amino acid oxidase; Pollegioni L et al.; A protocol is presented for preparing Rhodotorula gracilis D-amino acid oxidase in homogeneous form and in high yield in 3 to 4 days . The method takes advantage of (a) cell rupture by alternate freeze-thawing, (b) use of DEAE-Sepharose to bind contaminants, and (c) enzyme binding to a Mono S column . The D-amino acid oxidase isolated by this means has the same spectral and catalytic properties as the enzyme previously obtained, and possesses improved long-term stability. Biochim Biophys Acta, 1992 Mar 27, 1120(1), 11 - 6 Specificity and kinetics of Rhodotorula gracilis D-amino acid oxidase; Pollegioni L et al.; D-Amino acid oxidase purified from the yeast Rhodotorula gracilis is a flavoenzyme which does not require exogenous FAD for maximum activity . The enzyme showed temperature and pH activity optima centred between 40 and 45 degrees C and between 8.0 and 8.5, respectively; a broad pH and ionic strength range of stability and a more limited range of thermostability was determined . The enzyme stability was markedly influenced by the presence of 2-mercaptoethanol . Apparent kinetic parameters for a number of substrates were determined: nonpolar and aromatic D-amino acids appeared to be the best substrates . Steady state measurements carried out at different oxygen concentrations indicated that for D-alanine the kinetic pattern is consistent with a Ping Pong Bi Bi mechanism; kcat values on D-alanine and D-valine are 43,250 min-1 and 31,370 min-1, respectively . L-Amino acids did not inhibit enzyme activity; several aromatic and aliphatic carboxylic acids proved to be competitive inhibitors of the enzyme and their ki values were determined . The reported properties of R . gracilis D-amino acid oxidase markedly distinguish it from other characterized D-amino acid oxidases. Wei Sheng Wu Xue Bao, 1992 Feb, 32(1), 11 - 6 {Biotransformation of zearalenone}; Wu L et al.; The conversion of Zearalenone by some strains of microorganisms was investigated . When the selective strains of Rhodotorula sp., Arthrobacter sp., Saccharomyces sp., and Candida sp . were incubated by shaking or standing at 28 degrees C for 72 h with an alcoholic solution of Zearalenone as the substrate at a concentration of 2-10 mg/ml ethanol (50-100 micrograms/ml medium), it was readily converted to give Zearalenols, consisting either mainly of the alpha-isomer (e.g . 96% in case of Rhodotorula sp . and 84% in case of Arthrobacter sp . as determined by HPLC) or beta-isomer (e.g . 91% and 92% in Saccharomyces sp . and Candida sp., respectively) . The structure of the product was confirmed by 13C-NMR, MS and HPLC. Biochem J, 1992 Jan 1, 281 ( Pt 1), 211 - 8 Mechanistic and active-site studies on D(--)-mandelate dehydrogenase from Rhodotorula graminis; Baker DP et al.; D(--)-Mandelate dehydrogenase, the first enzyme of the mandelate pathway in the yeast Rhodotorula graminis, catalyses the NAD(+)-dependent oxidation of D(--)-mandelate to phenylglyoxylate . D(--)-2-(Bromoethanoyloxy)-2-phenylethanoic acid {'D(--)-bromoacetylmandelic acid'}, an analogue of the natural substrate, was synthesized as a probe for reactive and accessible nucleophilic groups within the active site of the enzyme . D(--)-Mandelate dehydrogenase was inactivated by D(--)-bromoacetylmandelate in a psuedo-first-order process . D(--)-Mandelate protected against inactivation, suggesting that the residue that reacts with the inhibitor is located at or near the active site . Complete inactivation of the enzyme resulted in the incorporation of approx . 1 mol of label/mol of enzyme subunit . D(--)-Mandelate dehydrogenase that had been inactivated with 14C-labelled D(--)-bromoacetylmandelate was digested with trypsin; there was substantial incorporation of 14C into two tryptic-digest peptides, and this was lowered in the presence of substrate . One of the tryptic peptides had the sequence Val-Xaa-Leu-Glu-Ile-Gly-Lys, with the residue at the second position being the site of radiolabel incorporation . The complete sequence of the second peptide was not determined, but it was probably an N-terminally extended version of the first peptide . High-voltage electrophoresis of the products of hydrolysis of modified protein showed that the major peak of radioactivity co-migrated with N tau-carboxymethylhistidine, indicating that a histidine residue at the active site of the enzyme is the most likely nucleophile with which D(--)-bromoacetylmandelate reacts . D(--)-Mandelate dehydrogenase was incubated with phenylglyoxylate and either (4S)-{4-3H}NADH or (4R)-{4-3H}NADH and then the resulting D(--)-mandelate and NAD+ were isolated . The enzyme transferred the pro-R-hydrogen atom from NADH during the reduction of phenylglyoxylate . The results are discussed with particular reference to the possibility that this enzyme evolved by the recruitment of a 2-hydroxy acid dehydrogenase from another metabolic pathway. Microbiologica, 1992 Jan, 15(1), 83 - 7 Keratomycosis with an unusual etiology (Rhodotorula glutinis): a case report; Casolari C et al.; A case of deep keratomycosis with isolation of Rhodotorula glutinis is discussed . Keratoplasty, done immediately, prevented panophthalmitis and cured the patient . The etiology and pathogenesis of fungal keratitis is examined. J Appl Bacteriol, 1992 Jan, 72(1), 32 - 8 Causes of conductance change in yeast cultures; Owens JD et al.; The conductance change due to growth of Saccharomyces cerevisiae Y112, Zygosaccharomyces bailii M and Rhodotorula rubra NCYC 63 in culture media containing glucose, tartrate pH buffer and ammonium ions as sole nitrogen source was compared with that in a medium containing L-asparagine as sole nitrogen source . Decreases in conductance were observed in glucose-ammonium cultures of all three yeasts while little change occurred in cultures with L-asparagine as sole nitrogen source . This supports the hypothesis that the metabolic activity primarily responsible for conductance change in yeast cultures is the uptake of charged ammonium ions as nitrogen source and the reaction of protons with pH buffer compounds . Rhodotorula rubra cultures with L-asparagine as sole carbon source caused large increases in conductance with growth . Chemical analyses of culture filtrates showed that this increase in conductance was due to use of L-asparagine as carbon source and the excretion of nitrogen surplus to biosynthetic needs as ammonium . In addition, the production of aspartate, acetate and bicarbonate contributed to the increase in conductance. Arch Microbiol, 1992, 157(3), 279 - 83 Distribution and immunological characterization of microbial aldehyde reductases; Kataoka M et al.; The distribution of microbial aldo-keto reductases was examined and their immunochemical characterization was performed . p-Nitrobenzaldehyde, pyridine-3-aldehyde and ethyl 4-chloro-3-oxobutanoate reductase activities were found to be widely distributed in a variety of microorganisms . In immunodiffusion studies, most yeasts belonging to the genera Sporobolomyces, Sporidiobolus and Rhodotorula formed precipitin bands with anti-Sporobolomyces salmonicolor aldehyde reductase serum . Furthermore, the results of immunotitration experiments suggested that Sporobolomyces salmonicolor AKU 4429 contains other enzyme(s) which can reduce p-nitrobenzaldehyde, pyridine-3-aldehyde and/or ethyl 4-chloro-3-oxobutanoate, and which are inactivated by anti-Sporobolomyces salmonicolor aldehyde reductase serum. J Antibiot (Tokyo), 1991 Dec, 44(12), 1406 - 16 All eight possible mono-beta-D-glucosides of validoxylamine A . I . Preparation and structure determination; Asano N et al.; Validamycin A is the major and most active compound among the validamycin complex . Since the site of beta-glucosidic attachment to validoxylamine A (1) was expected to affect the activity against the pathogenic fungus, Rhizoctonia solani, all eight possible mono-beta-D-glucosides of 1 were prepared . 2-O-, 4-O-, 4'-O-, and 7'-O-beta-D-glucopyranosylvalidoxylamine A (2, 4, 6 and 9, respectively) were prepared by microbial beta-glycosylation of 1 with strains of Rhodotorula sp . 7-O- and 6'-O-beta-D-glucopyranosylvalidoxylamine A (5a and 8a, respectively) were prepared semisynthetically through microbial formation of 7-O-beta-D-glucopyranosylvalidamine (10), oxidation of the primary amine of 10 to a ketone, and coupling of the ketone derivative with valienamine, and through microbial formation of 6-O-beta-D-glucopyranosylvalienamine (11), and coupling of 11 with (2R)-(2,4/3,5)-2,3,4-trihydroxy-5-hydroxymethylcyclohexanone (12), respectively . 3-O- and 5'-O-beta-D-glucopyranosylvalidoxylamine A (3a and 7a, respectively) were chemically synthesized. Stomatologiia (Mosk), 1991 Nov-Dec, (6), 30 - 2 {The role of associative opportunistic flora in the development of odontogenic inflammatory diseases of the maxillofacial area}; Chumakov AA et al.; Morphologic and microbiologic study of the operation and biopsy specimens, obtained from 73 patients with odontogenic inflammatory processes has shown that in 38% of cases the inflammation was induced by mixed fungal and bacterial flora . Associations of staphylococci or streptococci with actinomyces, Candida, Penicillium, Rhodotorula were most frequently isolated . As a rule, weak patients developed odontogenic inflammatory processes with mycotic involvement, these processes often taking a chronic course . Qualitative composition of the fungal-and-bacterial associations should be borne in mind when planning therapeutic measures for such patients. Biochem Int, 1991 Jul, 24(4), 641 - 7 Protonmotive force in yeasts--pH, buffer and species dependence; Kotyk A et al.; Using yeast species Saccharomyces cerevisiae K, Rhodotorula gracilis, and Lodderomyces elongisporus, their intracellular pH value and their membrane potential were estimated at pH 3.5-7.5 in four different buffers: triethanolamine--phthalic acid (TEPA), citric acid--trisodium citrate (CASC), acetic acid--NaOH (AANA) and MES . The pHin followed the same pattern in all buffers, with rather constant values below pHout = 5 and again above pHout = 7 . The membrane potential decreased regularly with decreasing pHout . The apparent protonmotive force increased with decreasing pHout . It is seen that for all the yeast species pHin and pHout are the same between 5.0 and 6.0 which is thus the pH range of choice for various transport measurements . Of the four buffers, TEPA gives smoothest pHin dependences on pHout and, being metabolically inert, is the one to be recommended. Genes Dev, 1991 Jun, 5(6), 1022 - 31 mRNA-type introns in U6 small nuclear RNA genes: implications for the catalysis in pre-mRNA splicing; Tani T et al.; U6 small nuclear RNA is one of the spliceosomal RNAs involved in pre-mRNA splicing . In the fission yeast Schizosaccharomyces pombe, the U6 RNA gene was found to have an intron similar to a nuclear pre-mRNA intron, and it was proposed that the U6 intron might be inserted erroneously during pre-mRNA splicing . Using the polymerase chain reaction, we analyzed the U6 RNA genes of 52 organisms . In addition to the five species of Schizosaccharomyces, we found that the yeast species Rhodotorula hasegawae and Rhodosporidium dacryoidum also have mRNA-type introns in their U6 genes; however, in all the other organisms tested, we found no intron within the region of the U6 gene examined . Four introns and one intron are present in the R . hasegawae and R . dacryoidum U6 genes, respectively; and these introns are located at sites differing from the location of the Schizosaccharomyces U6 intron . Most of the U6 introns locate within the conserved domain, which is strikingly similar in structure to the catalytic center of the negative strand of the satellite RNA of tobacco ring spot virus . The introns of the S . pombe and R . dacryoidum U6 genes are located immediately adjacent to the nucleotides that were shown to be essential for the second step of the splicing reaction . These results support the notion that U6 RNA has a catalytic role in pre-mRNA splicing and that U6 introns originated from insertion of an excised intron during pre-mRNA splicing. Eur J Cell Biol, 1991 Jun, 55(1), 104 - 13 Expression of D-amino acid oxidase in Rhodotorula gracilis under induction conditions: a biochemical and cytochemical study; Perotti ME et al.; D-amino acid oxidase is expressed to a high level in the yeast Rhodotorula gracilis (0.3% of total cell protein) through induction by D-alanine in a defined growth medium . Monospecific polyclonal antibodies against pure enzyme were obtained . Western blot analysis showed that the enzyme is synthesized as the mature polypeptide . The localization of the enzyme was investigated by immunoelectron microscopy using the postembedding immunogold technique and by submicroscopic enzyme cytochemistry . D-Amino acid oxidase was detected in peroxisomes, and quantitation of immunoelectron microscopic data indicated that the enzyme is exclusively confined to these organelles . Immunoelectron microscopic observations are in complete agreement with biochemical data showing that the enzyme is not expressed in the absence of D-alanine . Morphometric analysis demonstrated that induction of D-amino acid oxidase synthesis is associated with a 241% increase of peroxisome volume density and with a 31% increase of peroxisome size as compared to cells grown on non-inducing medium. Eur J Biochem, 1991 Apr 23, 197(2), 513 - 7 A study on apoenzyme from Rhodotorula gracilis D-amino acid oxidase; Casalin P et al.; The apoenzyme of D-amino acid oxidase from Rhodotorula gracilis was obtained at pH 7.5 by dialyzing the holoenzyme against 2 M KBr in 0.25 M potassium phosphate, 0.3 mM EDTA, 5 mM 2-mercaptoethanol and 20% glycerol . To recover a reconstitutable and highly stable apoprotein, it is essential that phosphate ions and glycerol be present at high concentrations . Apo-D-amino acid oxidase is entirely present as a monomeric protein, while the reconstituted holoenzyme is a dimer of 79 kDa . The equilibrium binding of FAD to apoprotein was measured from the quenching of flavin fluorescence and by differential spectroscopy: a Kd of 2.0 x 10(-8) M was calculated . The kinetics of formation of the apoprotein-FAD complex were studied by the quenching of protein and flavin fluorescence, by differential spectroscopy and by activity measurements . In all cases a two-stage process was shown to be present with a fairly rapid first phase, followed by a slow secondary change which represents only 4-6% of the total recombination process . In no conditions was a lag in the recovery of maximum catalytic activity observed . The process of FAD binding to yeast D-amino acid oxidase appears to be of the type Apo + FAD in equilibrium holoenzyme, even though the existence of a transient intermediate not detectable under our conditions cannot be ruled out. FEMS Microbiol Lett, 1991 Mar 15, 63(1), 21 - 5 A survey of yeast ureases and characterisation of partially purified Rhodosporidium paludigenum urease; Phillips A et al.; Cell-free extracts of a selection of yeasts were analysed for urease activity . Species in the genera Filobasidiella, Rhodotorula and Rhodosporidium had the highest specific activities . Immune inactivation experiments showed widely different degrees of cross-reactivity between antiserum to jack bean urease and yeast ureases, with Rhodosporidium paludigenum (71%) the most and Schizosaccharomyces pombe (3%) the least affected . Only R . paludigenum urease was detected with anti-jack bean urease antiserum on Western blots . The urease of Rhodosporidium paludigenum was partially purified by column chromatography . The native enzyme was found to have a subunit size of 72 +/- 7 kDa probably in an octamer arrangement of 560 +/- 8 kDa, having a specific activity of 62.5 mumol urea hydrolysed min-1 (mg protein)-1 . The enzyme was stable in the pH range 5-11 with optimum activity at pH 7.8 . Vmax and Km values were determined as 65.2 +/- 3.8 mumol min-1 (mg protein)-1 and 3.81 +/- 0.47 mM, respectively. Experientia, 1991 Mar 15, 47(3), 232 - 5 Immunochemical studies on Rhodotorula gracilis D-amino acid oxidase; Pollegioni L et al.; Polyclonal antibodies were prepared from rabbit sera after immunization with holo- and apo-D-amino acid oxidase purified from R . gracilis . Both anti-holo- and anti-apoenzyme IgG fractions (as well as affinity-purified IgG) were highly specific: in blot-transfer analyses after SDS-PAGE only a 39 kDa band, corresponding to enzyme monomer, was recognized even in the partially purified yeast extract . No cross-reaction was detected with pig kidney D-amino acid oxidase . As a difference from the mammalian enzyme, yeast D-amino acid oxidase anti-holo- and anti-apoenzyme IgGs had different properties in inactivation and precipitation experiments, indicating the existence of different antigenicity sites related to the FAD-binding domain in the enzyme. Mikrobiol Zh, 1991 Jan-Feb, 53(1), 72 - 9 {The effect of nitrosoguanidine on carotene-synthesizing and pigment-free yeasts}; Sudenko VI; A number of mutants with a demand for amino acids, vitamins and nitrous bases has been obtained under effect of nitrosoguanidine (0.05%) on the yeast Candida utilis and carotene-synthesizing yeast Rhodosporidium diobovatum, Rhodotorula glutinis var . glutinis and Rh . rubra . Concentration of auxotrophs due to the death of prototrophs has been achieved in the studied yeast, with the exception of Rh . rubra using additional treatment by levorin (200 units/ml) . When selecting quickly growing mutants of carotene-synthesizing yeast obtained after treatment by nitrosoguanidine, the primary selection by the intensity of red-orange colour of the colonies proved to be more efficient than that by resistance to monoiodoacetic acid . The selected mutants of the pigmented yeast surpassed by primary culture as to the harvest of carotenoids (including beta-carotene) and biomass in the periodic and continuous processes. Biol Met, 1991, 4(2), 100 - 6 Silver tolerance and accumulation in yeasts; Kierans M et al.; Debaryomyces hansenii (NCYC 459 and strain 75-21), Candida albicans (3153A), Saccharomyces cerevisiae (X2180-1B), Rhodotorula rubra (NCYC 797) and Aureobasidium pullulans (IMI 45533 and ATCC 42371) were grown on solid medium supplemented with varying concentrations of AgNO3 . Although Ag+ is highly toxic towards yeasts, growth on solid media was still possible at Ag concentrations of 1-2 mM . Further subculture on higher Ag concentrations (up to 5 mM) resulted in elevated tolerance . The extent of Ag tolerance depended on whether Ag-containing plates were exposed to light prior to inoculation since light-mediated reduction of Ag+ to Ag0 resulted in the production of a less toxic silver species . Experimental organisms exhibited blackening of colonies and the surrounding agar during growth on AgNO3-containing medium especially at the highest Ag concentrations tested . All organisms accumulated Ag from the medium; electron microscopy revealed that silver was deposited as electron-dense granules in and around cell walls and in the external medium . X-ray microprobe analysis indicated that these granules were metallic Ag0 although AgCl was also present in some organisms . Volatile and non-volatile reducing compounds were produced by several test organisms which presumably effected Ag+ reduction to Ag0. DNA Seq, 1991, 1(3), 207 - 11 Analysis of the gene for phenylalanine ammonia-lyase from Rhodosporidium toruloides; Rasmussen OF et al.; We have cloned and sequenced the pal gene encoding phenylalanine ammonia-lyase (PAL) from Rhodosporidium toruloides strain CBS14 . Our data imply a different start codon and thus a different amino acid sequence for the N-terminus of PAL as compared to the previously published sequence for pal from R . toruloides strain IF00559 . Primer extension analysis shows three transcription initiation sites with non-translated leaders of 24-35 nucleotides . Upstream of these initiation sites is a long stretch rich in pyrimidines . PAL from R . toruloides is 78% and 37% homologous to PAL from Rhodotorula rubra and Petroselinum crispum, respectively . Alignment of the PAL sequences is related to data of enzyme function. Folia Microbiol (Praha), 1991, 36(1), 86 - 91 Enrichment of wheat bran by Rhodotorula gracilis through solid-state fermentation; Jacob Z; The potential oil-producing yeast Rhodotorula gracilis was found to produce higher yields of biomass (13.7 g/L) and lipids (20.3%) in a nitrogen-limited and economically cheaper medium (molasses without yeast extract) in a submerged fermentation system . But, when the yeast was grown on four different wheat bran media by solid-state fermentation technique, different media combinations affected the percent increase in biomass, protein, oil production, fatty acid profile and degree of saturation and unsaturation . The initial lipid content in the control medium was 3.5% while in a medium with wheat bran, molasses, and minerals it was 69.8% . The yeast did not produce alpha-amylase, amyloglucosidase and cellulolytic enzymes for the breakdown of wheat bran . The yeast produced red carotenoids, a precursor of vitamin B12 and some oligounsaturated fatty acids in the fermented product. Biodegradation, 1991, 2(2), 107 - 13 Cytochrome P-450-dependent catabolism of triethanolamine in Rhodotorula mucilaginosa; Fattakhova AN et al.; The yeast Rhodotorula mucilaginosa was able to grow in media containing triethanolamine or diethanolamine as the sole nitrogen source . During growth in the presence of triethanolamine, extracts of yeast cells contained increased levels of cytochrome P-450 dependent monooxygenase which catalyzed the oxidative N-dealkylation of aminoalcohols . Formation of diethanolamine, ethanolamine and glyoxylate from triethanolamine was demonstrated, and the identity of the products was verified by thin layer chromatography . These observations suggested the following scheme of triethanolamine catabolism: triethanolamine----diethanolamine + glycolaldehyde, diethanolamine----ethanolamine + glycolaldehyde, ethanolamine----NH3 + glycolaldehyde----glycolate----glyoxylate----glycerate pathway. Gig Sanit, 1990 Dec, (12), 45 - 7 {Changes in the mutagenic effect of a medium containing aflatoxin B1 as a result of the yeast activity}; Borisenko AE et al.; Changes in the mutagenic activity of the nutrient medium containing aflatoxin Br as a result of living activity of the yeast Rhodotorula mucilaginosa I B has been studied . Reduction of mutagenic activity of the medium when tested on the strains Salmonella typhimurium TA98 (6.3 times fold), TA100 (2.2 times fold), AG262 (2 times fold) has been revealed . The data obtained leads to the conclusion that the technology, based on the use of the indicated strain of the yeast for the treatment of food and feed stuffs contaminated by aflatoxin B1, can be used. Boll Soc Ital Biol Sper, 1990 Jun, 66(6), 575 - 80 {Microbiological profile in water-supply conduits from a clogged well}; Aulicino FA et al.; This article presents the results of an investigation involving bacterioflora in a water well clogged for the presence of biomass . The water well, placed in a zone near Rome, showed some problems about the water quality and about the extraction of water . The examination of the interior of the pipes showed the presence of biomass . The biomass was examined microscopically and bacteriological analyses were carried out on it . Heterotrophic bacteria were enumerated with three different media by direct count, Pseudomonas sp., yeasts and fungi also by spread plate method . The anaerobic Sulphate Reducing Bacteria were investigated by "Most Probable Number" technique . The results of the analyses showed the presence of protozoa and algae . Moreover high quantity of bacterial flora as heterotrophic bacteria and Pseudomonas sp . were revealed . Sulphate Reducing Bacteria were enumerated in low quantities . Sphaerotilus natans, Actinomyces and Rhodotorula were identified . The clogging problems arose from the presence of filamentous microorganisms as Sphaeroilus natans and Actinomyces sp . When microorganisms of this kind are present in aquifers they can multiply massively if the conditions are favorable. Am J Vet Res, 1990 Apr, 51(4), 550 - 5 Serum IgG antibody concentrations against environmental microbes in mares and foals during different seasons and effect of stabling practices; Ripatti T et al.; Over periods of 22 and 14 months, IgG antibody concentrations in serum samples obtained monthly from 14 mares and 19 foals, respectively, were measured by use of ELISA against antigens of the following environmental microbes: Aspergillus umbrosus, Penicillium brevicompactum, Rhodotorula glutinis, Absidia corymbifera, Aspergillus fumigatus, Humicola grisea, Micropolyspora faeni, and Thermoactinomyces vulgaris . The mares and foals were on pasture from early June until early October, then were stabled during the winter season until the following June . In the mares, increased antibody concentrations against most microbes were observed typically in midwinter and late spring when the horses were stabled; antibody concentrations against R glutinis, however, peaked in August . Concentrations differed between the summer and winter seasons and, in most instances, between 2 consecutive years and correlated with amounts of rainfall during the previous harvest season . In the foals, circulating passively acquired antibodies disappeared within 3 to 4 months after birth . During the first year of life, substantially increased autogenous antibody concentrations were observed only against R glutinis . Antibody concentrations against the other microbes increased gradually toward the end of the indoor season . In a group of foals transferred indoors in autumn, 6 weeks later than the other foals, antibody concentrations were lower when measured in December . Results supported the view that, to minimize exposure to microbial spores during the winter season, horses should be kept outdoors as much as possible and attention should be focused on improving the ventilation in stables and the quality of feeds and beddings. Antonie Van Leeuwenhoek, 1990 Apr, 57(3), 153 - 8 Yeasts and fungi occurring in ensiled whole-crop maize and other ensiled vegetable crops; Middelhoven WJ et al.; The yeast flora of whole-crop maize ensiled for two weeks was predominated by Candida holmii, C . lambica, C . milleri, Hansenula anomala and Saccharomyces dairensis . Inoculation with other yeast species reported in the literature to prevail in maize or wheat silages did not alter the yeast flora . At 25 or 30 degrees C the ascomycetous fermentative species found at 20 degrees C were accompanied with ascomycetous non-fermentative fungi, i.c . Exophiala jeanselmei and Verticillium psalliotae, by the non-fermentative imperfect basidiomycetous yeast Rhodotorula mucilaginosa and by the weakly fermentative imperfect ascomycetous yeast Trichosporon adeninovorans . The yeast flora of other vegetable crops, ensiled at 20 degrees C for two weeks, was predominated by the same species that prevailed in ensiled maize, provided the crop did not contain mustard oils or menthol . If these compounds occurred in the crops, the yeast flora was predominated by nonfermentative species like Candida famata, Stephanoascus ciferrii, Rhodotorula minuta, Rh . rubra and Trichosporon cutaneum. Acta Odontol Scand, 1990 Feb, 48(1), 3 - 10 Oral mycology; Stenderup A; Yeasts occur commonly in the oral cavity in healthy individuals . The prevalent species is Candida albicans (about 60-70% of all isolates) . C . glabrata and C . tropicalis come next, followed by other Candida species and genera (Rhodotorula, Saccharomyces, etc.) which are all of rare occurrence and transient . The yeast flora increases in many patient groups, especially those who are immunocompromised . C . albicans is the most important species, being the cause of almost all cases of yeast infections in the region, often in association with other species . The number isolated from the oral cavity depends on testing site and methods used . C . albicans can be typed by means of serology (types A and B), by biotyping, by morphology, by means of sensitivity to killer factors, by electrophoretic karyotyping, DNA fragments, and immunoblotting . Such methods may be of value epidemiologically . Switching in Candida morphology is associated with changes in micromorphology and physiology . Several non-yeast fungi may affect the oral cavity, most frequently in association with lung or disseminated infections. Biochim Biophys Acta, 1990 Jan 29, 1033(1), 23 - 30 ATP:citrate lyase of Rhodotorula gracilis: purification and properties; Shashi K et al.; ATP:citrate lyase was purified from the oleaginous yeast Rhodotorula gracilis to homogeneity as judged by polyacrylamide gel electrophoresis, using a novel citrate-Sepharose procedure . The enzyme was found to have a molecular weight of 520,000 and consisted of four identical subunits (Mr = 120,000) . Two minor low molecular weight bands were observed on SDS-PAGE (Mr 51,000 and 49,000) . Trypsin digestion experiments indicated that these could have been the result of limited proteolysis by an endogenous trypsin-like proteinase . In this respect, it resembles the mammalian ATP:citrate lyase . The enzyme was stimulated by NH+4 ions and inhibited by palmitoyl, lauroyl, oleoyl, myristoyl and stearoyl-CoA esters, glutamate and glucose 6-phosphate but not by acetyl-CoA or shorter chain fatty acyl-CoA esters . The enzyme exhibited normal Michaelis-Menten kinetics for citrate; however there was a 3-fold increase in Km with a high concentration of Cl- ions (0.25 M) . The possible regulatory roles of ATP:citrate lyase in R . gracilis are discussed in the light of these findings. J Biochem (Tokyo), 1990 Jan, 107(1), 151 - 9 Distribution of aspartate aminotransferase activity in yeasts, and purification and characterization of mitochondrial and cytosolic isoenzymes from Rhodotorula minuta {corrected}; Yagi T et al.; The distribution of aspartate aminotransferase activity in yeasts was determined . The number of species of the enzyme in each yeast was determined by zymogram analysis . All the yeasts, except for the genus Saccharomyces, showed two or three activity bands on a zymogram . From among the strains, Rhodotorula minuta {corrected} and Torulopsis candida were selected for examination of the existence of yeast mitochondrial isoenzymes, because these strains showed two clear activity bands on the zymogram and contained a high amount of the enzyme . Only one aspartate aminotransferase was purified from T . candida: the component in the minor band on the zymogram was not an isoenzyme of aspartate aminotransferase . On the other hand, two aspartate aminotransferases were purified to homogeneity from R . minuta {corrected} . The components in the main and minor activity bands on the zymogram were identified as the mitochondrial and cytosolic isoenzymes, respectively, in a cell-fractionation experiment . The enzymatic properties of these isoenzymes were determined . The yeast mitochondrial isoenzyme resembled the animal mitochondrial isoenzymes in molecular weight (subunits and native form), absorption spectrum, and substrate specificity . The amino acid composition was closely similar to that of pig mitochondrial isoenzyme . Rabbit antibody against the yeast mitochondrial isoenzyme, however, did not form a precipitin band with the pig mitochondrial isoenzyme. Infect Control Hosp Epidemiol, 1989 Nov, 10(11), 511 - 4 Pseudoepidemic of Rhodotorula rubra in patients undergoing fiberoptic bronchoscopy; Hoffmann KK et al.; Between March and June 1988, Rhodotorula rubra was isolated from the bronchial washings of 30 of 56 (54%) patients undergoing bronchoscopy at a North Carolina community hospital . Pulmonary disease consistent with invasive fungal pneumonia was not apparent for any patient . Repeat sputum cultures were performed on 11 patients, none of whom were positive for R rubra . Investigation revealed fungal contamination of two brushes used to clean the bronchoscope channels and one positive sample of the tub water used to test the integrity of the bronchoscope prior to cleaning and disinfection . Control measures instituted were high-level disinfection of all equipment used to clean the bronchoscopes, including the brushes, complete air drying of the bronchoscopes before storing and storage of equipment in closed cabinets . An additional case one month after instituting these measures prompted the addition of a final 70% ethyl alcohol rinse of the bronchoscopes immediately prior to storage . Over a six-month period no additional cases have been identified . Despite published disinfection guidelines, pseudoepidemics and infections from contaminated equipment continue to appear . This pseudoepidemic investigation revealed a site for contaminating bronchoscopes that has not been previously reported, the inner cannula cleaning brushes . This emphasizes the need for stringent adherence to recommended cleaning and disinfection guidelines. Ann Ig, 1989 Nov-Dec, 1(6), 1647 - 56 {Results of an airborne spore study in various regions of southern Sardinia}; Palmas F et al.; Fungal air spores can play a significant role in several allergic manifestations . Therefore, the identification of geographic areas of mould distribution could be helpful to the clinician, especially if associated with fungal air spore recording in homes or working environments of sensitized subjects, in determining the real clinical importance of sensitization to fungi . On this basis, we studied the occurrence of airborne fungi at two urban sites and at two rural sites in the South of Sardinia, from May 1987 to April 1988, using the gravity plate method . Our survey has pointed out a significant difference about the occurrence of airborne spores in the areas sampled . Spore concentrations were lower at the urban sites during all the survey period . On the whole 6319 fungal colonies belonging to 28 different genera have been found . Cladosporium, Alternaria, Penicillium and Aspergillus, represented by a range of species, were the most common fungi identified in all sites examined . Remarkable the incidence of Yeasts, represented by the genera Candida, Saccharomyces, Rhodotorula and Sporobolomyces . Aureobasidium, Stemphilium, Botrytis, Chaetomium, Mucor and Rhizopus have been found in all sites but they have not been steadily isolated during the survey . Several other genera have been found only sporadically . Our results seem to confirm that fungal air spores, because of its quantity and variety, can represent a serious problem for human health in Sardinia. Chem Pharm Bull (Tokyo), 1989 Aug, 37(8), 1995 - 8 Preparation of chiral, highly functionalized cyclopentanes and its application to the synthesis of prostaglandin E1; Okano K et al.; This paper describes the preparation of the polyfunctionalized cyclopentane ((+/-)-5) by silica gel-catalyzed air-oxidation, and its kinetic resolution by means of microbial reduction with Rhodotorula rubra to afford optically pure (-)-5 (greater than 99% ee) . Starting with (-)-5, a new route to prostaglandin E1 was established. Arch Roum Pathol Exp Microbiol, 1989 Jul-Sep, 48(3), 275 - 82 Experimental studies on the persistence in distilled water of certain conditional pathogenic fungi; Peter Z et al.; The authors followed up the behaviour in distilled water of 8 fungus strains belonging to four species (Candida albicans, C . krusei, Geotrichum candidum and Rhodotorula) kept at various temperatures (i.e . +4 degrees, +18 degrees and 25 degrees C) . The average and the maximum survival periods were found to be as follows: C . albicans--476/1138 days, C . krusei--411/1138 days, G . candidum--127/219 days, and R . rubra--139/226 days . All strains revealed periodically multiplication bursts of variable intensity depending on the kind of species and the temperature at which the cultures were maintained . These findings plead for the existence of cryptic periods of growth in fungi, too . Although, during the experiments, the variants occurred as concerns the morphological and cultural characteristics, sugar fermentation, sugar and nitrate assimilation, germ tube formation did not undergo any modifications . The pathogenic characteristics of C . albicans strains for rabbit were retained even after 1096 days maintenance in distilled water at 18 degrees C. J Bioenerg Biomembr, 1989 Jun, 21(3), 321 - 34 Analysis of the H+/sugar symport in yeast under conditions of depolarized plasma membrane; Severin J et al.; H+/sugar symport in the obligatory aerobic yeast Rhodotorula glutinis was analyzed under conditions where the plasma membrane was selectively depolarized by the lipophilic cation tetraphenylphosphonium (TPP+) . Control experiments showed that this treatment did not impair the transmembrane delta pH, the cell energy charge, and the function of plasma membrane H+-ATPase . The kinetic data were fitted to elementary functions derived from a model constructed on the basis of some simplifying premises for ordered (either C + H+ + S or C + S + H+) and random reaction mechanisms . In addition, the comparison of the kinetic parameters in fully energized and depolarized cells provided information about the free carrier charge . It was concluded that the binding sequence of formation of the ternary carrier/H+/substrate complex follows a random mechanism and that the carrier bears a negative charge. Arch Biochem Biophys, 1989 May 1, 270(2), 419 - 31 The role of carotenoids in preventing oxidative damage in the pigmented yeast, Rhodotorula mucilaginosa; Moore MM et al.; Rhodotorula mucilaginosa is an obligate aerobic yeast which contains a high concentration of carotenoid pigment . To test whether carotenoids are able to protect R . mucilaginosa against oxidative injury, yeast cells in liquid culture were incubated with duroquinone (DQ) (100 microM), a redox-cycling quinone known to generate intracellular O2- . or were grown in a hyperoxic atmosphere (80% O2) under conditions where carotenoid concentrations were altered either intracellularly or extracellularly . Neither of these oxidative challenges affected cell growth unless carotenogenesis was blocked by the addition of diphenylamine (50 microM) . In the diphenylamine-treated nonpigmented cells, growth was completely inhibited by DQ and by hyperoxia . In normoxia, however, diphenylamine alone reduced growth by only 30% . The growth inhibition observed in diphenylamine-treated cells exposed to hyperoxia was primarily mycocidal rather than mycostatic since plating of these cells onto solid media revealed that only 25% of the cells were viable after 50 h of incubation when compared to plated control cells . Addition of 10 microM beta-carotene to diphenylamine-treated cells completely prevented the growth inhibition caused by either hyperoxia or DQ . Carotenoids, therefore, are able to prevent oxidant-induced cytotoxicity in R . mucilaginosa . Analysis of the absorption spectra of chloroform extracts of beta-carotene-supplemented cells showed that beta-carotene, not the endogenous carotenoid, torularhodin, was the major carotenoid present in these cells . Superoxide dismutase (SOD) activity in R . mucilaginosa was compared with that of another yeast, Saccharomyces cerevisiae by two methods: (i) activity staining of proteins separated by gel electrophoresis and (ii) measurement of inhibition of ferricytochrome c reduction . By these techniques, the R . mucilaginosa SOD activity had the characteristics of Mn-SOD . No Cu/ZnSOD activity was detected . Thus, the apparent absence of Cu/ZnSOD may make the antioxidant capability of endogenous carotenoids even more critical in preventing oxidative damage in R . mucilaginosa. Biochim Biophys Acta, 1989 Mar 6, 1010(3), 325 - 9 31P-NMR evidence for cytoplasmic acidification and phosphate extrusion in syringomycin-treated cells of Rhodotorula pilimanae; Reidl HH et al.; 31P-NMR spectroscopy was used to investigate the effects of the phytotoxin, syringomycin, on phosphate metabolism and intracellular pH changes in the yeast Rhodotorula pilimanae . Syringomycin, at levels between 20 and 60 units per 10(8) cells, caused a cellular efflux of orthophosphate . At 40 and 60 unit per 10(8) cells, the efflux was accompanied by a decrease in polyphosphate and an acidification of the cytoplasm . At low temperatures (5 degrees C) and with 75 units per 10(8) cells, these effects were more rapid and pronounced . The efflux of phosphate was confirmed by chemically assaying extracellular phosphate after syringomycin treatment. Eur J Biochem, 1989 Mar 1, 180(1), 199 - 204 Properties of D-amino-acid oxidase from Rhodotorula gracilis; Pilone Simonetta M et al.; The flavoprotein D-amino-acid oxidase was purified to homogeneity from the yeast Rhodotorula gracilis by a highly reproducible procedure . The amino acid composition of the protein was determined; the protein monomer had a molecular mass of 39 kDa and contained one molecule of FAD . The ratio between A274/A455 was about 8.2 . D-Amino-acid oxidase from yeast showed typical flavin spectral perturbations on binding of the competitive inhibitor benzoate and was reduced by D-alanine under anaerobiosis . The enzyme reacted readily with sulfite to form a covalent reversible adduct and stabilized the red anionic form of the flavin semiquinone on photoreduction in the presence of 5-deazariboflavin; the 3,4-dihydro-FAD form was not detectable after reduction with sodium borohydride . Thus D-amino-acid oxidase from yeast exhibited most of the general properties of the dehydrogenase/oxidase class of flavoproteins; at the same time, the enzyme showed some peculiar features with respect to the same protein from pig kidney. Z Hautkr, 1989 Jan 15, 64(1), 21 - 3 {Fungal involvement of the penis in patients with penile condylomata acuminata}; Gallenkemper G et al.; In a study on 129 patients with penile condylomata acuminata we recognised an incidence of 32% penile yeast affection . Candida was found in 54%, Torulopsis in 30% and Rhodotorula in 17% of all cases . The high rate of yeasts not belonging to the candida species is remarkable . There was no correlation between our test results regarding the cell-mediated immunity against candida albicans and the local yeast infection. Appl Environ Microbiol, 1989 Jan, 55(1), 190 - 7 Biotransformation and detoxification of T-2 toxin by soil and freshwater bacteria; Beeton S et al.; Bacterial communities isolated from 17 of 20 samples of soils and waters with widely diverse geographical origins utilized T-2 toxin as a sole source of carbon and energy for growth . These isolates readily detoxified T-2 toxin as assessed by a Rhodotorula rubra bioassay . The major degradation pathway of T-2 toxin in the majority of isolates involved side chain cleavage of acetyl moieties to produce HT-2 toxin and T-2 triol . A minor degradation pathway of T-2 toxin that involved conversion to neosolaniol and thence to 4-deacetyl neosolaniol was also detected . Some bacterial communities had the capacity to further degrade the T-2 triol or 4-deacetyl neosolaniol to T-2 tetraol . Two communities, TS4 and KS10, degraded the trichothecene nucleus within 24 to 48 h . These bacterial communities comprised 9 distinct species each . Community KS10 contained 3 primary transformers which were able to cleave acetate from T-2 toxin but which could not assimilate the side chain products, whereas community TS4 contained 3 primary transformers which were able to grow on the cleavage products, acetate and isovalerate . A third community, AS1, was much simpler in structure and contained only two bacterial species, one of which transformed T-2 toxin to T-2 triol in monoculture . In all cases, the complete communities were more active against T-2 toxin in terms of rates of degradation than any single bacterial component . Cometabolic interactions between species is suggested as a significant factor in T-2 toxin degradation. Microbios, 1989, 57(232-233), 157 - 66 Yeast-suspension as soiling matter in disinfectant testing; Loberg RM et al.; Using the Kelsey-Sykes capacity-test, it was found that a sterile yeast suspension used to simulate 'dirty' conditions, gave an increased effect of Chloramine T against the fungi Candida albicans, Aspergillus fumigatus, Geotrichum candidum and Penicillium sp . compared with the effect under 'clean' conditions . This effect was not found with the fungus Rhodotorula rubra nor on the various bacteria tested . The enhanced effect was found with respect to both Chloramine T and Chloramine B, but not with the sodium hypochlorite solution when tested on C . albicans . This effect was due to a diffusible factor from the yeast cells . The factor was evident in the solution after heating of the yeast-cell suspension and in unsterilized yeast-cell suspension left at room temperature for 2 h or more . The effect of Chloramine T on the fungi C . albicans and A . fumigatus was reduced as expected when the yeast suspension was replaced by 20% normal horse serum . The results indicate that using sterile yeast suspensions in this type of test, may erroneously give high fungicidal effects of Chloramine, and thus lead to an incorrect use-dilution concentration, especially if the determination is made on the basis of the effect observed only under dirty conditions. Vopr Virusol, 1988 Nov-Dec, 33(6), 732 - 7 {Mannan sulfates--inducers of plant resistance to viral infection}; Kovalenko AG et al.; Mannan sulphates (MS) synthesized on the basis of extracellular linear mannan (LM) of Rhodotorula rubra induce resistance of Immune-580 tobacco and thornapple (Datura stramonium) to tobacco mosaic virus (TMV) . The resistance is manifested in a decrease in the number and/or size of viral local lesions (LL) in MS-treated (mg/ml) leaf halves . The reduction in the LL size does not seem to be due to the direct inhibition of TMV multiplication by the polysaccharide as the virus accumulation in the tissues of the systemic host (Samsun tobacco) does not decrease when MS is used 15 min after infection . The induced resistance is partially inhibited by actinomycin D and completely by heating (32 degrees C) . Unlike MS, neutral LM decreases only the number of LL on the treated parts of the tissue but does not influence their size . The antiviral activity of LM does not change in the presence of actinomycin D . The possible mechanisms of the LM and MS protective effect in plants are discussed. Allergol Immunopathol (Madr), 1988 Sep-Oct, 16(5), 359 - 62 Anemophilus fungi in the western Brazilian Amazon basin; Pecher SA et al.; The prevalence of anemophilus fungi was studied in three small towns located at the Brazilian border with Colombia and Venezuela (a hot and humid zone) during the month of July . On a single collection carried out in different spots, colonies were cultivated which could be attributed to eighteen different species of anemophilus fungi with predominance of Mucor (64%), Candida (55%), Rhodotorula (38%) and Penicillum (38%) . The alternaria species, a very potent airbone allergen, was found only in one of the three collection spots with high prevalence of respiratory tract allergies. Antibiot Khimioter, 1988 May, 33(5), 359 - 62 {Study of the fractions and fibrinolytic activity of fungal mannan}; Elinov NP et al.; Characteristics of the fraction composition of extracellular mannan produced by Rhodotorula rubra are presented . Various lots of the polysaccharide mainly contained two fractions similar by their chemical structures and differing in the solution relative viscosity . HPLC was used for determining the molecular weight of the samples . In the isolated fractions it differed 3-5 fold . Relationship between the fibrinolytic activity of the polysaccharide and its molecular weight was revealed . The samples of mannan with the molecular weight of 400-500 kD had the highest capacity for lowering the fibrinogen blood levels in rats . The polysaccharide with the molecular weight of less than 100 kD had practically no fibrinolytic activity. J Infect, 1988 Mar, 16(2), 187 - 91 Rhodotorula rubra ventriculitis; Donald FE et al.; We describe a case of post-operative ventriculitis in an immunocompetent patient caused by an unusual organism, namely Rhodotorula rubra . The patient was treated successfully with antifungal agents. Biochimie, 1988 Feb, 70(2), 183 - 5 Transport of L-glucose by Rhodotorula glutinis; Pinkerton MD et al.; The kinetics of L-glucose transport by Rhodotorula glutinis were studied over a 720-fold range of sugar concentrations . Analysis of the saturation isotherm revealed the presence of a one-carrier system for L-glucose in the plasma membrane of Rhodotorula glutinis . This carrier exhibited a km of 3.7 +/- 0.3 mM . D-Ribose was found to be a competitive inhibitor with a Ki of 19 +/- 1 mM . The results suggest that L-glucose is transported by the high-Km, D-ribose carrier . L-Glucose was transported against a concentration gradient and the transport was inhibited by the proton conductor 2,4-dinitrophenol. Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi, 1988 Feb, 21(1), 1 - 8 Cloning of a LEU gene and an ARS site of Rhodotorula glutinis; Ho YR et al.; Genomic library of DNA from an extracellular protease-producing yeast strain, Rhodotorula glutinis K-24, was constructed, using Escherichia coli plasmid vector PBR322 . A LEU gene from R . glutinis was cloned, and found to complement leu- mutations in E . coli and Saccharomyces cerevisiae . In E . coli, the LEU gene in the cloned yeast DNA fragment was efficiently expressed when inserted into the vector in one orientation . In S . cerevisiae, the R . glutinis LEU gene was efficiently expressed when inserted into a shuttle vector YEP13 in both orientations, suggesting that the isolated R . glutinis DNA fragment contains a promotor sequence of R . glutinis in front of the LEU gene . In addition, our data suggests that the cloned LEU fragment also contains an ARS (autonomously replication sequence) site of R . glutinis that could function in S . cerevisiae. Antonie Van Leeuwenhoek, 1988, 54(4), 367 - 75 Glutathione and glutathione metabolizing enzymes in yeasts; Casalone E et al.; Total glutathione content, glutathione peroxidase, glutathione transferase and glutathione reductase activities have been measured in 12 species of yeasts . All the strains tested contained glutathione, though in different amounts, as well as the above mentioned enzymes . To discriminate between the selenium-dependent and the selenium-independent form, glutathione peroxidase activity has been measured with both H2O2 and cumene hydroperoxide . Rhodotorula glutinis appeared to be the only strain in which the selenium-dependent form was not found, but this yeast exhibited the highest level of selenium-independent glutathione peroxide activity as compared to the other strains. Zentralbl Mikrobiol, 1988, 143(7), 523 - 8 {Experimental studies relative to the persistence of several facultative pathogenic fungi in river water}; Peter M et al.; Under laboratory conditions survival time of 3 fungi species (Candida albicans, Geotrichum candidum, Rhodotorula rubra) in river water of various quality and temperature has been studied . The mean (and the maximum) survival time was as follows: 82 (240) d for C . albicans, 210 (578) d for G . candidum and 333 (606) d for R . rubra . Differences concerning survival time were recorded in dependence on temperature and quality of water . All the 3 strains were multiplied periodically . Variants of culture character could be noticed during the experiments . The flora of association seems to have a considerable influence on the survival time of the fungi studied . The very long persistence of fungi enables them to become widespread by means of water, and in such a way that they pollute environment. Antonie Van Leeuwenhoek, 1988, 54(4), 331 - 43 Movements of protons coupled to glucose transport in yeasts . A comparative study among 248 yeast strains; Loureiro-Dias MC; In 248 strains representing 205 yeast species, changes in pH coupled to glucose addition were followed in unbuffered cell suspensions . Alkalinization of the external medium elicited by glucose, indicating a H+-glucose symport was observed in 34% of the strains, most of them belonging to the genera Rhodotorula, Hansenula and Candida . H+ uptake coupled to glucose transport was observed only after exhaustion of glucose in growth media . This observation was taken as an indication that, in general, the synthesis of H+-glucose symport is under the control of catabolite repression . Subsequently to the addition of glucose, in most yeasts (82%) acidification was observed . This ability is probably related to the creation of a proton-gradient across the plasma membrane and is generally distributed among yeasts. Yeast, 1987 Dec, 3(4), 263 - 70 Effects of yeast suspension density on the accumulation ratio of transported solutes; Kotyk A; The previously described effect of cell suspension density on metabolic and transport phenomena in yeast, apparently caused by inhibition by dissolved carbon dioxide, is also observed with the accumulation ratio of both sugars and amino acids where not only a kinetic but also a energetic factor comes into play . Unlike all previously measured metabolic and transport parameters, the dependence of the accumulation ratio on suspension density is not monotonic but shows a pronounced maximum in the range of 4-8 mg dry wt/ml, depending on yeast species and on cultivation conditions . In Rhodotorula gracilis and in Lodderomyces elongisporus it is not due to CO2 but is semiquantitatively related to the proton-motive force across the plasma membrane as well as to the intracellular ATP content . It is observed both in oxygen and in argon, over a wide range of pH values and of temperatures, but it is suppressed by metabolic inhibitors . It is expressed only in a range of transported solute concentrations between about 0.1 and 10 mM. Antibiot Med Biotekhnol, 1987 Sep, 32(9), 658 - 62 {IR spectrophotometric study of a mixed culture of Streptococcus lactis, strain MSU, and Rhodotorula colostri with agitation of the medium}; Kozlova IuI et al.; Physiological aspects of Streptococcus lactis, strain MSU development in mixed culture with Rhodotorula colostri were studied in connection with nisin biosynthesis . By the IR spectra the average content of the main components in the monoculture cells of S . lactis and its association with the yeast in the stationary growth phase was the following by dry weight: 54-58 per cent of protein, 14-16 per cent of nucleic acids, 26-28 per cent of carbohydrates and 3-5 per cent of lipids . Glucose and nitrogen in the fermentation broth were consumed completely . A significant quantity of KH2PO4 remained in the fermentation broth . Lactic acid excretion was observed . S . lactis, strain MSU was the leading component of the association under the studied cultivation conditions because just its IR spectra dominated in the spectra of the mixed culture. Appl Environ Microbiol, 1987 Aug, 53(8), 1780 - 4 Microbial transformation of precocene II: oxidative reactions by Streptomyces griseus; Sariaslani FS et al.; Various species of "Streptomyces," "Aspergillus," "Rhodotorula," "Brevilegnia," "Syncephalastrum," and "Stysanus" were found to transform precocene II to three major metabolites . These major biotransformation products were isolated from a preparative-scale incubation of precocene II with Streptomyces griseus and were conclusively identified as (-)cis- and (+)trans-precocene II-3,4-dihydrodiols and (+)-3-chromenol . 18O2 incorporation studies indicated the involvement of a monooxygenase enzyme system in precocene II transformation by S . griseus . A mechanism is proposed for the formation of (+)-3-chromenol. Mycopathologia, 1987 Jun, 98(3), 133 - 40 Antimicrobial activity of protoanemonin, a lactone from ranunculaceous plants; Mares D; Protoanemonin, a component of Ranunculus bulbosus, was tested as an antifungal agent on selected strains of dermatophytes and yeasts . The minimum inhibitory concentrations ranged from 2.0 to 7.5 X 10(-4) M and the minimum lethal concentrations from 3.8 X 10(-4) M to greater than 1.0 X 10(-3) M . The most sensitive dermatophyte tested was Epidermophyton floccosum, and the most sensitive yeast Rhodotorula glutinis . The effects of different culture media and of light on the sensitivity of Rhodotorula glutinis to protoanemonin were also tested . Structural analogies between protoanemonin and other cytotoxic unsaturated lactones, and the reversal by the amino acid cysteine of the antifungal action suggest a possible mechanism of action. Arch Microbiol, 1987 Jun, 148(1), 77 - 82 An improved method for protoplast formation and its application in the fusion of Rhodotorula rubra with Saccharomyces cerevisiae; Evans CT et al.; Protoplasts from various strains of red-pigmented yeasts were generated at high frequency using improved procedures . The use of sulphur-containing amino acids and 2-deoxyglucose in growth media led to impaired cell wall synthesis and rendered cells very susceptible to treatment with mercapto-ethanol and various lytic enzymes . Use of individual lytic enzymes separately resulted in relatively low frequencies of protoplasts from most of the red yeasts examined, whilst use of beta-glucuronidase, Novozyme and Zymolyase in series markedly increased stable protoplast formation . The latter effects were shown to be strain specific . The ability to generate large numbers of red yeast protoplasts prompted the attempt to examine intergeneric fusion between auxotrophs of a strain of Saccharomyces cerevisiae and Rhodotorula rubra . Putative hybrids were selected as variously-pigmented prototrophic colonies growing on minimal medium and stabilised by subculturing on the latter medium . Unusual cream, orange and yellow hybrid colonies were generated, composed of cells of varying morphologies (chains, multibudded) . The majority of stable hybrids contained one nucleus, although several heterokaryons were also observed . Some hybrids possessed the phenotypes of both parents: fusant wcat41 grew as rapidly as the S . cerevisiae parent but also contained an inducible phenylalanine ammonia-lyase (PAL) which appeared to be more active than that of the Rhodotorula parent. Health Phys, 1987 May, 52(5), 543 - 7 Growth hormesis: a by-product of control; Stebbing AR; Data from experiments, in which colonies of a hydroid, Laomedea flexuosa, were exposed to a range of Cu2+ concentrations and a marine yeast, Rhodotorula rubra, was exposed to a range of Cd2+ concentrations, not only exhibit hormesis, but also suggest how its occurrence in growth experiments might be explained . When growth data are considered as normalized specific rates against a time base, their oscillatory form indicates the output of a growth regulatory mechanism whose behaviour can be used to interpret the typical concentration-response curve exhibiting hormesis . Advantages may be conferred upon organisms whose growth control mechanisms overcorrect in response to low levels of inhibitory loading by toxic agents (stimulus), while at higher concentrations it is the overloading of such c