Rhapidosomes were demonstrated by electron microscopy to be present abundantly in the autolysate of two strains belonging to the B type of Clostridium botulinum. They were revealed as hollow cylinders with rather round tips, which were 280 to 400 in diameter and varied in length, regardless of the strains. The time lapse observations of autolytic process suggested that the rhapidosomes were produced by the original disintegration of membranous structures such as the cytoplasmic membrane and the mesosomes to turn into rod bodies, and by final liberation into the autolysates. The purified rhapidosomes were found to be composed of 62.5% protein, 32.0% lipid, and 1.7% ribonucleic acid, without detection of deoxyribonucleic acid or carbohydrates. The rhapidosomes were toxic to mice, 50% lethal dose being about 1μg of their protein. When actively growing cells of both strains were treated with Mitomycin- C or ultraviolet ray, several kinds of phages or phage component-like structures were found. The morphological characteristics of these structures were described, and proved not to resemble the rhapidosomes.
Tadpole-like cells of Sporolactobacillus inulinus are nothing but partial spheroplasts formed by the imbalance between cell-elongation and cell-wall formation. This phenomenon was termed auto-spheroplastization. By applying flavin-linked lactate dehydrogenase technique, surface of this organism was found to act as a barrier against the invasion of self-producing D(-)- lactic acid. Auto-spheroplastization can also conveniently be used for showing the actual osmotic barrier located on a cytoplasmic membrane.
Cellular fatty acids of 38 strains representing 6 species of genus Pediococcus and of some related bacteria were analyzed by gas-liquid chromatography using capillary columns, and correlation between their fatty acid spectra and taxonomy of the genus Pediococcus was examined. Characteristics in fatty acid biosynthetic pathway of each organism inferred from the observed fatty acid compositions were regarded as a good criterion for grouping. Pediococci tested were separated into the following three groups: Group I, P. cerevisiae and P. halophilus (P. soyae); Group II, P. acidilactici and P. pentosaceus; Group III, P. urinae-equi, P. homari, and Aerococcus viridans. Among these groups, fatty acid spectra of the Group III members were significantly different from those of the other groups, especially from the point of fatty acid biosynthesis. This might suggest the phylogenetical unrelatedness of the Group III members to other Pediococci. Culture age and growth media influenced the relative proportions of certain fatty acids, but such a difference did not affect the group separation.
The fatty acid composition of plasmodia of slime molds, Fuligo septica, Perichaena colticalis, and Badhamia sp., is very similar. The most abundant are oleic and linoleic acids. The composition of fatty acids in sporangia and plasmodia of Fuligo septica was found to be different in that the former contains far less 16:0 and more 20:1(11) than the latter. Furthermore, the former contains an unidentified acid which is lacking in the latter.
Determinative studies were carried out on an obligatory anaerobic, sulfate- reducing bacterium (strain No. 61) isolated from a pond water in Skarvs Nes district in the East Antarctica. This sulfate-reducing bacterium was nonsporulating, sigmoid or straight rods with a single polar flagellum, gram negative, and possessed cytochrome c3 and desulfoviridin, characteristic of the genus Desulfovibrio. It could grow with lactate, malate, pyruvate, or choline when sulfate was present in the culture medium and had a stable sodium chloride requirement. These observations dinicated that strain No. 61 closely resembled Desulfovibrio desulfuricans var. aestuarii.
Electron microscopy revealed that the cell walls of carotenogenesis form of (-) strain of Blakeslea trispora are strikingly thick compared with those of white form. The chemical composition of the purified cell walls of the two forms is described. The cell walls consist mainly of a xylose polysaccharide, a glucosamine polysaccharide which is probably chitin, some protein, lipid materials, and a trace of nucleic acid. In addition, smaller quantities of glucose, galactose, and mannose have been detected. In spite of the small quantities of lipid materials, the cell walls of the yellow form contain high amounts of carbohydrate and glucosamine polysaccharides. It is concluded that the difference in environmental conditions can bring changes in the molecular architecture of microbial cell walls and hence stimulate the production of morphologically and biochemically different forms of the microorganism.
Exposure of the hyphae of (-) strain of Blakeslea trispora to air greatly stimulated the accumulation of carotenes and induced changes in the composition of the cell wall lipid. Fractionation of wall lipid revealed the presence of different lipid classes (phospholipids, monoglycerides, diglycerides, ergosterol, free fatty acids, triglycerides, and waxes). Phospholipids, free fatty acids, and waxes constitute the major part of wall lipid. The difference in wall lipid between non-pigmented and pigmented hyphae was quantitative rather than qualitative. The phospholipid fraction mainly contained phosphatidic acid, diphosphatidylglycerol, glucosylphosphatidylglycerol, and a trace of phosphatidylglycerol. No qualitative or quantitative difference was observed in the phospholipid components of the phospholipid fractions.
Volvariella volvacea (Bull. ex. Fr.) Sing. is a fungus of the tropics and subtropics. The changes in ultrastructure from the growing apex to the proximal part of a single hyphal cell could be distinguished not only by the distribution of cellular organelles but also by the electron density of cytoplasmic matrix, although the definite demarcation of the zone was impossible. The apical zone is characterized by abundant small apical vesicles. Mitochondria are clustered in the transitional region. The subapical zone is rich in a variety of cytoplasmic organelles including the nuclei. Towards the proximal region ageing proceeds and density of cytoplasmic matrix decreases. The cytoplasmic vesicles with dense granules found in both subapical and aged regions are considered to be formed either from the bulging cisternae of endoplasmic reticulum or from a system of cisterna membranes. The vesicles often broke from their limiting membranes and released their dense contents into the cytoplasm. They were also fused with vacuoles as well as with plasma membrane. Although the chemical nature of these vesicles is not known, their possible functions are discussed.
Edited and published by : Applied Microbiology, Molecular and Cellular Biosciences Research Foundation/Center for Academic Publications Japan Produced and listed by : TERRAPUB, Center for Academic Publications Japan/Shobi Printing Co., Ltd. (-Vol.60,No12), Center for Academic Publications Japan/InternationalAcademic Printing Co., Ltd.(-Vol.54,No1)