On the basis of the ubiquinone system comprised of Q-10[Q-9], the DNA-DNA hybridization and the electrophoretic patterns of enzymes, we propose to substitute Acetobacter liquefaciens (Asai 1935) Yamada and Tahara sp. nov. for Acetobacter aceti subsp. liquefaciens (Asai 1935) De Ley and Frateur 1974. A description and a comparison of this species with other species in the genus Acetobacter Beijerinck 1898 are presented. The type strain is IFO 12388 (=IAM 1834).
A radiotracer technique using 35SO4 is presented as an alternative method for testing the efficacity of inhibitors of sulfate-reducing bacteria under environmental conditions. This method is compared with two other conventional techniques for evaluating biocide efficacity by testing microorganism survival. Differences between the methods are described. The radiotracer technique gives a direct measure of the sulfate reduction rate and by using it the effect of inhibitors can be evaluated in situ. This method should be considered when choosing a test for the effects of biocides.
Fourteen of 18 strains of Bacillus subtilis (natto) were found to harbor plasmids. Twelve strains, which showed biotin requirement for growth and viscous substance productivity, contained a single plasmid species. These plasmids, including pLS15, pLS17, pLS19 and pTA1014, were classified into the same type of pUH1, the functional plasmid encoding γ-glutamyltranspeptidase (γ-GTP) gene, based on results of molecular weights and restriction patterns. Strain IFO3022, which did not require biotin but produced slightly viscous substance, harbored a single plasmid, pLS11. The plasmid pLS11 had showed a molecular weight and restriction patterns entirely different from pUH1. But the 4.2-kb BamHI fragment of pUH1 was found to be strongly hybridized with 3 fragments generated with HindIII from pLS11. Plasmid pLS11, therefore, may be a functional plasmid linked with polyglutamate (PGA) production. Strain IFO3023, which did not require biotin or produce a viscous substance, was found to have 3 plasmid species, but none of the plasmid DNA hybridized with the probe. The other 4 strains which did not require biotin or produce viscous substance did not harbor plasmid DNA. The results described above strongly suggest that the 5.7-kb plasmid, encoding the γ-GTP gene responsible for PGA production, exists widely in B. subtilis (natto) strains, which require biotin for the growth and produce PGA.
Glutamine was produced by coupling the glutamine synthetase from Micrococcus glutamicus with sugar fermentation of baker's yeast as an energy-generating system. With 429 units/ml of glutamine synthetase and 40mg/ml of yeast cells, 120mM of glutamate was converted completely to glutamine in 3-4hr, and 160-170mM of glutamine (approximately 23-25g/l) was formed in 5hr from 350mM of the substrates glutamate and ammonium chloride with a yield of about 40%, based on the energy released by the yeast during sugar fermentation. The activity ratio of sugar fermentation and glutamine synthetase was again confirmed to be important for achievement of energy-coupling in systems with high concentrations of glutamate and ammonium chloride. Glutamine formation was partially stimulated by the addition of Mg2+ in concentrations at which yeast fermentation of sugar showed no response to the cation, but was greatly stimulated by the addition of a small amount of Co2+. This same Co2+ effect was also observed in the reaction with cell-free extracts or toluol-treated cells of M. glutamicus.
The taxonomic and phylogenetic relationships among fifty strains of the genus Hansenula were studied by comparing seven enzymes electrophoretically. The patterns were uniform within each of nine species and four varieties. Hansenula platypodis and Hansenula polymorpha each showed a variation in pattern within themselves. The twenty-five Hansenula species tested were clearly distinguishable from each other by their enzyme patterns. Hansenula anomala var. anomala and H. anomala var. schneggii produced identical patterns for all seven enzymes. On phylogenetic line 1 by WICKERHAM, adjoining species showed relatively similar enzyme patterns, whereas each species of line 2 produced a characteristic pattern. Hansenula wingei on line 4 was similar to Hansenula canadensis on line 3 with respect to certain enzymes.
Viable Kluyveromyces fragi yeasts cells were successfully entrapped in polyacrylamide and kappa-carrageenan gel beads. Small amounts of precultured yeast cells were mixed with specific concentrations of gel solutions and gel beads of uniform size were manufactured by a gelation process. For both batch and continuous fermentation systems, the cells grew well in the gel. In batch fermentation trials, there was no significant shift in the pH profile for either the polyacrylamide or the kappa-carrageenan immobilized cell systems. Continuous fermentations were carried out in a column with an initial packed gel height of 13cm but with different dilution rates using 10% lactose solutions reconstituted from sweet whey powder as the medium. The immobilized growing cell systems exhibited high and stable activity for ethanol production under steady-state conditions. A maximum productivity of 7.8g/l-hr at a dilution rate of 0.800hr-l for polyacrylamide immobilized cell and 13.3g/l-hr at 0.679hr-l for kappa-carrageenan immobilized cell was obtained. Of the two methods tested, the use of kappa-carrageenan for immobilizing yeasts for ethanol production from whey was better.
An electrophoretic comparison was made of 13 enzymes in 53 strains of methanol-assimilating yeasts. Nine strains of Candida boidinii were divided into two closely related interspecific clusters. The methanol-assimilating Hansenula yeasts showed electrophoretic patterns of enzymes very similar to one another, suggesting a close interrelationship. Pichialindnerii and Candida methanolovescens showed similar physiological and chemotaxonomic characteristics, but they differed in the electrophoretic patterns of their enzymes. Pichia methanolica and three strains of Pichia cellobiosa showed the same electrophoretic patterns and chemotaxonomic characteristics. Eleven strains of Hansenulacapsulata and its supposed anamorph Candida molischiana showed different electrophoretic patterns of enzymes and DNA base composition. They were divided into 5 clusters on the basis of these characteristics. The facts suggest the heterogeneity of these species. It would not be appropriate to regard C. molischiana simply as an anamorph of H. capsulata. The electrophoretic patterns of the enzymes exhibited a good correlation with the groups of methanol-assimilating yeasts, based on the DNA base composition, the coenzyme Q systems, and the proton magnetic resonance spectra of cell-wall mannans.
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Edited and published by : Applied Microbiology, Molecular and Cellular Biosciences Research Foundation/Center for Academic Publications Japan Produced and listed by : TERRAPUB, Center for Academic Publications Japan/Shobi Printing Co., Ltd. (-Vol.60,No12), Center for Academic Publications Japan/InternationalAcademic Printing Co., Ltd.(-Vol.54,No1)