Properties of phosphate acetyltransferase which was partially purified from Leuconostoc mesenteroides IFO 3426 were studied, and it was found that some properties of this enzyme are rather similar to those of the transferase from Clostridium kluyveri than that from Escherichia coli B, and it was also found that aeration did not significantly affect the activity of the transferase invivo.
Four kinds of bacterial cultures, which produce H2S from organic sulfur compounds such as thiophene, dimethyl sulfide, 1-butanethiol, polysulfides, as well as from crude oil, residue oil, and asphaltene, were isolated from sludges collected from oil well or reservoir bottom of crude oil. The culture which decomposes thiophene contained bacterial cells which are gram-negative and of rod shape with average dimension of 3×0.5μ. The bacteria grow optimally at pH 7.2-7.8 and at 38° in N2 or H2. Polypeptone is essential for their growth, and addition of FePO4 increases the rate of H2S production. The cell-free extract of thiophene-decomposing bacteria catalyzes the production of H2S from thiophene in the presence of methyl viologen in H2.
Studies have been conducted on fruiting body formation in the wood-rotting basidiomycete Lenzites saepiaria. Basidiospores were inoculated into a liquid malt extract medium and the mycelium was harvested after 48-72hr. Washed mycelium placed on cotton pads saturated with a defined medium developed fruiting structures in about 3 weeks. A source of carbohydrate, nitrogen, and phosphorous was essential for this morphogenesis. Spores produced under these conditions were identical in appearance and physiological properties to those obtained from wild basidiocarps.
When the spores of a mutant of Bacillus subtilis appearing to have a temperature-sensitive defect in the ribosomes were incubated at 48°, the process of germination underwent naturally, but not the process of outgrowth. Moreover, dormant spores of this mutant were found to be less thermo-resistant than those of the wild type strain.
RNA synthesis in an asporogenous mutant of Bacillus subtilis, which seemed to be an early sporulating mutant, was investigated. This mutant failed to synthesize spore-specific RNA during the stationary phase, but induction of histidase, which appears to represent the transcription of vegetative genes, occurred even during the stationary phase, when no significant induction of the enzyme was observed in the sporogenous strain. From these results, it was speculated that RNA polymerase transcribing sporulating genes was different from RNA polymerase transcribing vegetative genes, and the former type of RNA polymerase did not function in this asporogenous mutant.
DNA base composition (GC content) of 84 cultures of Saccharomyces and related yeasts was investigated. Saccharomyces yeasts employed in the present experiment showed the GC content from 32.4 to 45.9%. the range of which was about 13%. Three groups having GC values of 32.4-33.7%, 38.3-40.7%, and 42.7-45.9% were recognized, and most of the species had a GC content of 40% or so. Of the four groups discriminated by VAN DER WALT, the two (the first and third groups) were considered to be natural taxonomic groups on the basis of GC content. The first group (Saccharomycessense stricto) had a GC value of 38.3-40.7% with a small range of variation of 2.4%. This group is homogeneous also in serological characteristics investigated by TSUCHIYA and his co-workers. Members of the third group showed a GC value of 42.7-43.4% except S. florentinus and S. microellipsodes. As far as is known, this group (with two exceptions mentioned above) is also homogeneous in serological characteristics. It is considered that it would be better to separate this group from Saccharomyces as Torulaspora. S. florentinus and S. microellipsodes would be better included in the first group or in the second.
Respiratory and luminescent systems in Photobacterium phosphoreum were reinvestigated by using intact cells and supernatant from cold osmotic shock. Time course pattern and activity of luminescence were quite different between the in vivo and in vitro systems. In the in vitro system, chemicals generally used as respiratory inhibitors inhibited luminescence rather than NADH oxidation. Luminescent activities were completely lost in both systems by UV irradiation at 360mμ. Seventy per cent of respiratory activity in the in vitro system survived after UV irradiation, while almost none of that in the invivo system remained. None of flavins and quinones added to both systems resulted in an increase in luminescence. Extraction of the in vitro system with solvents gave 2-3 fold increase in luminescent activity. Decanal addition gave a similar effect. Possibility of participation of quinones and aldehydes in luminescence is discussed.
Intracerebral injection of vegetative myxamoebae of strains of Polysphondyliumpallidum caused 80 to 100% mortality in mice, whereas a 30 to 50% mortality occurred with strains of Dictyostelium giganteum and D. mucoroides. Death is attributable to an unidentified toxic factor. Histopathologically a giant cell formation was seen in the spleen of mice. This cell was different from Langerhan's or foreign body giant cell. Rats injected intracerebrally behaved similarly. Intranasal instillation of myxamoebae in guinea pigs caused transient pneumonia. Myxamoebae do not multiply in the brain tissues of mice or rats, or in the lungs of guinea pigs. Intranasal instillation of vegetative myxamoebae is less pathogenic than free living amoebae like Hartmanella culbertsoni, H. rhysodes, Naegleria sp. (Culbertson strain HB-1), or Naegleria aerobia.
The DNA base composition (GC content) of 119 strains of Candida was investigated. The strains employed showed a GC content from 30.0 to 63.2%. The intrageneric variation of GC content (about 33%) was the largest among the genera of yeasts hitherto investigated and it clearly suggested highly heterogeneous nature of this genus. From the viewpoint of GC content, the genus Candida seemed to be bimodal. One group had a GC content below 50%, and imperfect forms of ascosporogenous yeasts were included in this group. The other group had a GC content above 50%. All the urease-positive species and species supposedly related to heterobasidiomycetes were included in this group. Classification of Candida proposed by several investigators were evaluated on the basis of GC content. Serological characteristics and proton magnetic resonance spectra of polysaccharides were considered to be good taxonomic criteria as the conventional methods are.