Pantothenate-requiring baker's yeast, Saccharomyces cerevisiae strain BA-1, died to a large extent when Casamino acids-containing medium was newly given to the pantothenate-deficient cells harvested in an arithmetic linear phase of growth. Methionine contained in the Casamino acids stimulated the cell death pronouncedly. To the pantothenate-deficient cells grown in the medium containing Casamino acids as the nitrogen source (CA medium), addition of NaCl or KCl at concentrations higher than 0.5M markedly prevented the cell death. In contrast, addition of sucrose or mannitol to the CA medium was ineffective in such a protective action. The number of dead cells decreased with elevation of pH values up to 7.5. The death of cells was not stimulated by the addition of EDTA over a wide range of from 10-4 to 3×10-2M. As to the effect of various long-chain fatty acids on the growth and death of cells, palmitic acid was the most effective for reduction of death ratio, and stearic acid was the second one, while unsaturated fatty acids showed much less effect. When the yeast was grown in a pantothenate- free CA medium, striking changes occurred in fatty acid composition of the cells. Although the cells incubated in the CA medium both with and without pantothenate consisted of the same kinds of fatty acids, the amounts of C16:1, C18:1, and especially C16:0 fatty acid were pronouncedly smaller in the cells grown without pantothenate. The differences between these results and those previously obtained about the cell death due to biotin deficiency were discussed.
Morphological, cultural, biochemical, and physiological characteristics of 112 strains of coryneform bacteria were examined. Coryneform bacteria were taxonomically divided into seven groups on the basis of the combination of the characteristics of gram-stain, motility, presence of metachromatic granules, pleomorphism, effect of citrate on cell form, acid formation from carbohydrates, assimilation of organic acids, hydrolysis of gelatin, extracellular DNase, urease, and cell wall composition.
Classification and concepts of the genera of coryneform bacteria were described on the basis of the results obtained previously. Coryneform bacteria were divided into seven groups at the generic level by the combination of mode of cell division, principal amino acid in the cell wall, the guanine- cytosine content (GC content) in DNA, and biochemical and physiological characteristics. The concepts of several genera were made clearly and a new genus Curtobacterium was proposed. The scheme for differentiation of the genera of these bacteria was presented, and problems for classification of coryneform bacteria were discussed.
For the purpose of these series of mycological survey, 220 dung samples of wild and domestic animals for determination of species of pyrenomycetous Ascomycetes were collected from various geographic regions of Japan, including Ryukyu and Bonin Islands. Fifteen species of Podospora (the Sor-dariaceae) from numerous collections are described and illustrated. Most of them were also obtained in living cultures. All species are new records in Japan.
Eleven species, ten of which are new records in Japan, belonging to the genus Sporormiella (the Sporormiaceae, Loculoascomycetes) are described and illustrated. Like Podospora, most species are predominatingly found on the dungs of herbivorous animals in Japan.