A new yeast, Candida acutus, was isolated from sulfited grape must, and its description is given. The yeast forms septated and short mycelial cells in ring or pellicle, and has a GC content in DNA of 54.7%, the positive activities of urease and extracellular DNase, and the Q9 of coenzyme Q system.
Cell division properties of temperature-sensitive mutants of Escherichia coli K-12, isolated for ampicillin resistance, altered cell-wall synthesis, and/or cross-linking of peptidoglycan chains were examined. When the incubation temperature of exponentially growing cultures of these mutants was shifted from 32° to 42°, cell division was inhibited and morphological changes were observed. This suggested that inhibition of cell division at 42° was due to a conformational change in temperature-sensitive protein(s). A return to the incubation temperature of 32°, after a short period of growth at 42°, resulted in recovery of cell division. Several of these mutants show recovery in the presence of chloramphenicol indicating that restoration of the normal phenotype occurs by the conformational change of affected protein(s). One mutant which grows into spherical cells at 42° and contains hypercross-linked peptidoglycan chains, will snot regain rod-shaped cell morphology or normal cell division in the presence of nalidixic acid, an inhibitor of DNA synthesis. In this mutant maintenance of cell shape and cell division depends on chromosome replication. These data demonstrate a direct connection between proper biosynthesis and cross-linking of peptidoglycan and cell-shape maintenance and division in E. coli.
Intra- and extra-cellular activities of protease, nuclease, and invertase were examined with four newly isolated morphological mutants of Aspergillusnidulans. As far as the four mutants subjected to the investigation were concerned, extracellular activities of these enzymes were markedly changed. Some relationship between morphological mutation and extracellular enzyme formation was assumed and this assumption was supported genetically with two mutants which gave rise to wild-type revertants.
Glycolate test was carried out on 86 cultures including 51 coryneform bacteria, 13 nocardiae, 4 mycobacteria, 4 gordonae, and related organisms. Among coryneform bacteria, it was found that about two-thirds of the strains was acetyl type concerning the acyl type on the cell wall, and about one-third was glycolyl type. The latter strains were distributed in the limited taxa, that is, three species in high-GC taxon of genus Corynebacterium, one in genus Curtobacterium, and several strains in a complicated taxon being not classified. However, all strains of genus Mycobacterium and most of genus Nocardia except two doubtful strains were proved to have the cell wall of glycolyl type. Among "Mycobacteriumrhodochrous complex", Gordona group appeared exceptionally to have quite a unique acyl type, namely, a glycolyl type of glycerol-suppression positive. The bacteria of genera Actinomadura, Oerskovia, and Streptomyces were shown to be the acetyl type. The classification of "Corynebacterium-Mycobacterium-Nocardia" group was discussed on the basis of these results and additional data.
Cellular fatty acid composition of 8 species of sulfate-reducing bacteria was determined. Five species of Desulfovibrio, non-sporulating sulfate-reducing bacteria, were divided into two major groups based on the composition. One group contained unsaturated branched-chain fatty acids as major fatty acids and the other did not. Desulfovibrio vulgaris, Desulfovibriodesulfricans, and Desulfovibrio salexigens in the former group contained iso-C15:0, C16:0, and iso-C17:1 as the most abundant acids. In Desulfovibrioafricanus which was also classified into the former group, the relative amount of each acid was largely different from that in the 3 species mentioned above. The most abundant acid was C18:1Δ11 and iso-C16:1, iso-C17:1, and anteiso-C17:1 were detected as the next most abundant acids. In contrast, Desulfovibrio gigas which belonged to the latter group contained anteiso-C15:0 and iso-C14:0 as major acids and the overall profile of the composition was remarkably different from the 4 species in the former group. The cellular fatty acid composition in 3 species of Desulfotomaculum, sporulating sulfate-reducing bacteria, was different from that in the Desulfovibrio species. The 3 species were divided into two major groups. Desulfotomaculum nigrificans contained odd-numbered saturated branched-chain fatty acids (iso-C15:0 and anteiso-C15:0) as major acids, and in Desulfotomaculum orientis and Desulfotomaculum ruminis, even numbered straight-chain fatty acids (C16:0 and C16:1) were the major acids. Heterogeneity in the cellular fatty acid composition in both of non-sporulating and sporulating species suggests taxonomical confusion in the sulfate-reducing bacteria.
Soluble cytochrome c from Methylomonas methanica was purified to homogeneity and its properties were characterized. The molecular weight as determined by gel filtration is 18, 000 and the subunit size as determined by sodium dodecyl sulfate gel electrophoresis is 17, 000. The amino acid composition and spectral properties of cytochrome c are presented. Antisera prepared against the purified cytochrome from Methylomonas methanica cross-reacted with cytochrome c in cell extracts of various obligate methane-utilizing bacteria.