Nine strains of obligately psychrophilic bacteria, which were isolated from regions near Showa Station in Antarctica, were studied taxonomically. These strains were identified as Curtobacterium psychrophilum sp. n. (1 strain), Cytophaga antarctica sp. n. (3 strains), Cytophaga xantha sp. n. (1 strain), Spirillum pleomorphum sp. n. (2 strains), Micrococcus cryophilus McLean, Sulzbacker and Mudd, and Pseudomonas putrefaciens (Derby and Hammer) Long and Hammer (1 strain).
A new yeast, Candida pseudointermedia, was isolated from "Kamaboko, " a traditional fish-paste product in Japan, and its description was given. This yeast has a GC content in DNA of 44.4-44.9%, forms a mannan whose proton nuclear magnetic resonance spectrum has five signals in H-1 region, and agglutinates with factor antisera corresponding to antigens of 1, 4, 6, and 24, whose pattern is closely related to that of Candida intermedia.
Radioisotopically labelled compounds (14CO2, 32P-phosphates, [2-14C]-acetate, L-[4, 5-3H]leucine, [6-3H]thymidine, [2-14C]thymine, [5-3H]-uridine and [2-14C]uracil) were fed for 1hr to synchronized Chlorella cells at various stages of the cell cycle, and uptake and incorporation of the tracers into DNA, RNA, and protein of algal cells were examined. They showed more or less characteristic patterns in the process studied. The three kinds of macromolecular cell constituents took up the radioactivities of all the compounds tested, except in the case of [6-3H]-thymidine, whose radioactivity was incorporated into DNA and protein but not into RNA. 14C of CO2 seemed to be specifically or preferentially incorporated into chloroplast macromolecules under photosynthesizing conditions.
In the course of investigations on yeast cell production and on the metabolisms of methanol, two new species, Torulopsis nagoyaensis and Hansenula ofunaensis, were found in the yeasts isolated from various natural sources in Japan. Taxonomical studies of these new species are described.
Thirty-nine cultures were examined for the MK system, which belong to the coryneform genera Corynebacterium, Arthrobacter, Brevibacterium, Micobacterium, and Cellulomonas, and to the actinomycetous genera Mycobacterium, Nocardia, and Oerskovia. The coryneform bacteria were found to have the complex quinone systems composed of MK-8, MK-8 (H2), MK-8 (H4), MK-9, MK-9 (H2), MK-9 (H4), and MK-11. The actinomycetous organisms represented the systems of MK-8 (H4), MK-9 (H2), MK-9 (H4), and MK-9 (H6). These results indicate a heterogeneous nature of these organisms. Discussions are made on the classification, especially on several groupings.
Cells of Bacillus subtilis adsorbed on an anion-exchange resin, Dowex 1 in chloride form, were incubated in a growth medium in a batch or a continuous-flow system. In either system, the ratio of the number of spores to that of total organisms in the supernatant or in the effluent of adsorbed culture and the ratio on the resin surface were larger than the ratio in free cell culture and it was concluded that the spore formation of B. subtilis was significantly promoted by adsorption on the resin. When adsorbed cells were cultivated in a continuous-flow of growth medium, resin surface was nearly saturated with vegetative cells and spores during incubation. In this system, the ratio of the number of spores to that of total organisms was larger in the effluent than on the resin surface, suggesting that the spores tended to detach from the resin surface more easily than the vegetative cells. On the basis of these observations, a model for the growth and spore formation of B. subtilis on the resin surface was presented. Kinetic equations were formulated for the growth and spore formation of adsorbed cells and it was shown that the spore formation rate of adsorbed cells was larger than that of free cells.