Seven strains of cryophilic wine yeasts and two strains of mesophilic wine yeasts were investigated for their utilization of sugars, viability of ascospores in hybrid obtained from between cryophilic wine yeast and mesophilic wine yeast, electrophoretic karyotype, G+C content of DNA and DNA similarity in photobiotin microplate-hybridization. Six strains of cryophilic wine yeasts were identified as Saccharomyces uvarum and one strain of cryophilic wine yeast was identified as S. chevalieri according to The Yeasts, 2nd ed. (Lodder, J., ed., North Holland Publ. Co., Amsterdam, 1970) on the basis of mainly sugar utilization. However, ascospores of hybrids obtained from between cryophilic wine yeast and mesophilic wine yeast did not germinate. These cryophilic wine yeasts were similar to the type strain of S. bayanus (IFO 1127) in electrophoretic karyotype and G+C content. The cryophilic wine yeasts also showed high DNA similarity values to the type strain of S. bayanus and low DNA similarity values to the type strain of S. cerevisiae (IFO 10217). Accordingly, these seven strains of cryophilic wine yeasts were classified to S. bayanus. Additionally, another eight strains of S. bayanus, classified on the basis of DNA similarity, showed good fermentability at low temperatures accompanied by production of low amounts of ethanol at intermediate temperatures, the same as cryophilic wine yeasts. These results suggest that the fermentation characteristics are specific for S. bayanus. Two strains of mesophilic wine yeasts showed high DNA similarity values to the type strain of S. cerevisiae.
A strain of ballistosporous yeast, which was isolated from a dead leaf of Lindera obtusiloba collected at Mt. Fuji, was found to represent a new species. In traditional taxonomic criteria, it resembles Sporobolomycessubbrunneus and Sporobolomyces coprosmicola but showed low DNA relatedness to these two species. The name Sporobolomyces linderae is chosen for this yeast.
Four Acinetobacter isolates (SY1, SYD, BO2, IB2) were studied concerning lipolytic activity titrated on olive oil, biomass production, temperature and culture medium agitation. Fractionation of enzyme production was also investigated, as well as the effects of various temperatures on reaction speed and stability after heating. Finally, a series of substrates were tested so as to determine various capacities for lipid degradation. The biomass production was approximately identical for SY1, SYD and BO2 but slightly lower for IB2. On the other hand, lipolytic activity on olive oil was very variable among isolates, SY1 being the outstanding one in this field. As for temperature, SY1 and SYD had a maximum activity at 25°C and their enzymes were shortly degraded by heating, while BO2 and IB2 had a maximum activity at 45-50°C. All isolates were able to hydrolyze various substrates in the form of solution or emulsion, which warrants efficiency in the biodegradation of fats in wastewater treatment.
A new anamorphic yeast species, Candida stellimalicola Suzuki, Nakase et Komagata, is proposed for a strain isolated from Ma-Fueng (star apple) in Thailand. C. stellimalicola resembles Candida diversa, Candida silvae and Candida karawaiewii in traditionally employed taxonomic criteria, but is clearly differentiated from these three taxa by DNA-DNA hybridization, proton magnetic resonance (PMR) spectral patterns of cell wall mannans and serological characteristics of cell surface antigens. Practically, C. stellimalicola is distinguished from C. diversa by its ability to assimilate D-arabinose and DL-lactic acid, its inability to assimilate ribitol, and the lack of alcoholic fermentation, from C. silvae by a different vitamin requirement and its inability to assimilate ribitol, and from C. karawaiewii by its ability to assimilate L-lysine.
Effect of Cd, Cu, Ni, Fe and Al on the kinetics of NO3-, NH4+, urea and PO43- uptakes, nitrate reductase, glutamine synthetase, urease, alkaline phosphatase and ATPase activities revealed a common pattern of inhibition, but the intensity of toxicity was metal specific. A ligand-based toxicity was observed in the case of Al but not for Cu and Ni. A non-competitive inhibition of NO3- uptake and NR activity suggested an irreversible inhibition of uptake and assimilation of NO3- by the test metals used. Contrary to this the competitive inhibition of NH4+ uptake and glutamine synthetase suggested an active NH4+ metabolism even under metal stress. Further, the competitive inhibition of uptake and assimilation of urea by metals confirmed that in absence of NH4+ the alga can metabolize urea and meet its nitrogen demand. The test metals failed to interrupt PO43- metabolism when external PO43- pool was high or the organism was a PO4-3 accumulating one. This study suggested that for surviving in metal-stressed condition the cyanobacterium shifts from N2/NO3- to NH4+ utilization pathway.
Effects of incubation temperature and ethanol concentration on cell viability of two strains of cryophilic wine yeasts YM-84 and YM-126 were compared with those of mesophilic wine yeasts W3 and OC-2. The cryophilic wine yeasts showed certain cell viability in the presence of 10% ethanol at 8°C, the same as the mesophilic wine yeasts. At 25°C, however, viable cell numbers of these cryophilic wine yeasts were decreased, and this tendency became more marked with the presence of ethanol. Comparison of the composition of fatty acid in cells, YM-84 and YM-126 showed higher proportions of myristic acid to fatty acid, in addition to higher ratios of C16 fatty acids to C18 fatty acids. These phenomena suggest that these strains have different adaptation mechanisms against temperatures. Five strains of cryophilic wine yeasts selected in our culture collection showed the same fermentation velocity at the low temperature of 7°C as did YM-84 and YM-126, and at 28°C their ethanol yields were reduced. From these results, it can be concluded that good fermentability at low temperatures accompanied by production of low amounts of ethanol at intermediate temperatures is one of the fermentation characteristics observed among cryophilic wine yeasts.
Six strains of acidophilic chemoorganotrophic bacteria from acid mine drainage were studied in their taxonomic aspects. They were gram negative, aerobic, mesophilic, oxidase negative, catalase positive, urease positive, nonsporeforming, and rod-shaped. Carotenoid and bacteriochlorophyll a were formed. Two strains had a polar flagellum and other two strains fimbriae. They used a wide variety of organic compounds for growth, but did not use ferrous iron, elemental sulfur, and thiosulfate as the sole energy source. Acetate was inhibitory to growth. Growth was enhanced by adding high concentrations of glucose or complex organic compounds such as trypticase soy (BBL) and yeast extract. Methanol was utilized as the sole source of carbon and energy. The major ubiquinone was Q-10. The major cellular fatty acid was straight-chain unsaturated C18:1 acid. The hydroxy acid was 3-OH C14:0 acid. The DNA base composition was 66.2 to 68.1mol% guanine plus cytosine. The isolates showed relatively low levels of genetic similarity to Acidiphiliumcryptum and Acidiphilium organovorum. On the basis of the phenotypic, chemotaxonomic, and genotypic characters, we conclude the isolates as a new species, for which we propose Acidiphilium multivorum sp. nov. The type strain is AIU 301 (JCM 8867).
A new anamorphic yeast species, Candida sojae Nakase et al., is proposed for two strains isolated from an extraction process of water-soluble substances of defatted soybean flakes. Candida sojae resembles Candidatropicalis and Candida albicans, but differs from these two species by mol% G+C, DNA-DNA relatedness, electrophoretic enzyme patterns, and the proton magnetic resonance spectra of cell wall mannans. Practically, C. sojae is distinguished from C. tropicalis and C. albicans by its inability to ferment maltose and low maximum growth temperature below 40°C. It is also distinguishable from C. tropicalis and C. albicans serotype A by the lack of agglutination with mouse monoclonal antibody CA4-2.