(1) A strain of bacteriophage (phage S-a) attacking an amylase-forming bacterium, Bacillus subtilis var. amyloliquefacus (a.f.), was investigated with special reference to the host specificity of the phage, as well as its multiplication on protoplast hosts. (2) The protoplasts of the susceptible bacterial strain, Bacillus subtilis var. amyloliquefacus (a.f.), were found to be capable of adsorbing the added phage and producing infectious daughter phages. The rate of phage-adsorption and the burst number in the one-step growth-experiment were determined, and the results compared with those obtained with intact bacterial cells as hosts. (3) Protoplasts of non-susceptible bacteria, Bacillus subtilis NRRL 558 (non-a.f.), were also found to be capable of adsorption the phage but to a less pronounced extent and with no subsequent reproduction of the phage. (4) Protoplasmic membranes of susceptible and non-susceptible bacteria were equally found to adsorb phage particles, but in a non-specific way. (5) A correlation was discovered between lysozyme-susceptibility of bacterial cells and their capacity for phage-adsorption. The latter property was found to meet a necessary requirement, but not the sufficient condition for phage-susceptibility; Bacillus subtilis NRRL 558 (non-a.f.; lysozyme-susceptible; phage-adsorbing), for example, was found to be non-susceptible to phage S-a.
1) A new method of assaying bacteriophage was developed by combining a statistical treatment of the phage adsorption with a viable-counting method of the host bacterium which had been developed previously by the author. 2) By using the method, the infective process, especially of the adsorption of thermophilic phage and its thermal decay at higher temperatures, was investigated. 3) It was found that the phage had a high tolerance towards heat, and that the adsorption rate constant of the phage was far smaller than those of mesophilic phages.
1) Brevibacterium flavum, No. 2247 could grow in the acetate medium and accumulated a considerable amount of L-glutamate in its growing culture medium. 2) The growth factors and the concentration of acetate and ammonium ion in the medium were intimately related to the growth and to the L-glutamate accumulation as well. 3) Several strains of genera Brevibacterium and Corynebacterium besides Brevibacterium flavum, No. 2247 could grow in the acetate medium and accumulated a considerable amount of L-glutamate.
1) Brevibacterium flavum, N. 2247 could grow in the chemically defined medium and accumulated a considerable amount of L-glutamic acid in its growing culture medium. 2) It is likely that the effects of biotin on the cell growth and on the L-glutamate accumulation in the acetate medium are not so strict as shown in the glucose medium. 3) aspartic acid, glycine, succinic acid, citric acid and α-keto-glutaric acid were identified as by-products in the broth filtrate.
Many auxotrophic mutants were obtained from glutamic acid bacteria by UV, Co60 irradiation applying penicillin selection method. Mutants which accumulate ornithine, lysine, valine, homoserine, phenylalanine, diaminopimelic acid, α-aminobutyrate, tyrosine were found. Close relationships between accumulated amino acids and requiring substances were suggested. Lysine accumulating strains obtained in the present study are now being used in commercial production of lysine. The possibility of the application of accumulation of other metabolite by auxotrophs to industrial production was also discussed.
1. Isoleucine-less and leucine-less mutants of glutamic acid producing bacteria accumulated a considerable amount of valine in culture broth. Accumulation of this amino acid also occurred in the following mutants: threonine-less, threonine and methionine-less, arginine-less, (tryptophane+phenylalanine+tyrosine)-less and arginine or citrulline or ornithine-less. 2. Valine accumulation by isoleucine-less and leucine-less mutants occurred in limited concentration of requiring amino acids in media. And no accumulation occurred where these amino acids added in excess. 3. Lactic acid was found to accumulate in the presence of excessive amount of required amino acid and sufficient biotin in media. Valine accumulation took place in the presence of proper concentration of requiring amino acids. The tendency of glutamic acid accumulation was recognized in a small concentration of biotin. 4. It was suggested from cell suspension experiments that isoleucine inhibits enzyme formation rather than enzyme action, of valine accumulating system of a isoleucine-less mutant. 5. With the isoleucine-less mutant valine accumulation when cultured on a synthetic medium containg isoleucine was much low compared to those on NZ-amine medium. Addition of leucine or valine markedly increased the valine accumulation on the above synthetic medium. 6. Antagonisms among isoleucine, leucine and valine were observed in growth and valine accumulation. Speculation on the effect of leucine and valine mentioned above was made from these antagonisms and inhibiting action of isoleucine on enzyme formation of valine accumulating system.
(1) During the process of life cycle of Chlorella, as modified by the limited supply of sulfur and nitrogen source, changes of lipid and carbohydrate contents of the algal cells were followed. (2) It was found that an abnormally large amount of fat accumulated in the cells during the phase of sulfur starvation, while the content of carbohydrate decreased. (3) when the S-starved cells were transferred to a medium containing sulfate alone, the depleted level of carbohydrate in the cells returned to normal, The fat content of the cells, however, showed a tendency even to increase further. The abonormally accumulated fat disappeared rapidly when the S-starved cells were incubated in the medium containing both sulfate and nitrate. (4) It was concluded that in the S-deficiency some mechanism was in operation which was in favor of lipid synthesis and suppressive for the net formation of carbohydrate, and that a certain biochemical step requiring both S- and N-sources was essentially involved in the normal course of lipid metabolism.
Two strains of molds in different genus producing red pigments by interaction of each other were isolated from molds grown on paper label for export canned food and the phenomenon of red pigment formation was investigated. The results were as follows: (1) Both isolated strains were ascertained never to produce red pigments independently, but always produced them by interaction of each other. The pigments were also never produced by heterocaryone in anastomosis of two strains. (2) The maximum pigment formation was obtained at 48 hours in shaking submerged culture. (3) Mechanism of red pigments formation was supposed to be enzymatic reaction. (4) It was suggested that the pigments in the mycelium and culture filtrate were mixtures of several pigments and they may not be anthraquinones.