In order to clarify the mechanism of death of yeast due to biotin-deficiency in the presence of aspartic acid, changes in the activities of two kinds of biotin enzymes, pyruvate carboxylase and acetyl-CoA carboxylase, were examined. From the fact that the extent of decrease of pyruvate carboxylase activity in the cells cultured in the biotin-deficient NH4-medium was about two-fold larger than that of acetyl-CoA carboxylase in the same cells, it could be assumed that these cells were deficient in aspartic acid but not in fatty acids. In addition, when the biotin-deficient cells were transferred to biotin- free NH4-medium supplemented with a fatty acid mixture, the growth was the same as that in the medium without fatty acids. In the biotin-deficient NH4-medium, the growth might be restrained by the reduced activity of pyruvate carboxylase that limits the synthesis of aspartic acid, but when these cells were transferred to the biotin-free Asp-medium they could again begin to grow by producing cell protein and other nitrogenous substances with the supply of aspartic acid. However, during this growth, the lowered activity of acetyl-CoA carboxylase due to biotin deficiency decreased still more gradually, thus resulting in insufficient synthesis of fatty acids. Therefore, it may be that this unbalanced synthesis of cell components, leading especially to impairment of the cell surface structure containing fatty acids, is what makes the cells fall into death.
Non-pigmented methanol-dependent bacteria have been isolated in pure culture from a wide variety of natural sources. They are capable of growing only on methanol among many carbon sources tested, and showed no growth on ordinary nutrient media. These bacteria were identified as a new species, Methanomonas methylovora. The organisms are gram-negative, non- sporeforming rods, 0.4 to 0.7μ by 1.0 to 4.0μ in size, having a single polar flagellum. GC content of DNA is 51.2 to 53.6%. Some of them required a relatively high concentration of thiamine as an essential factor for cell growth, and produced an intracellular yellow pigment on methanol-containing agar medium.
Bud scar-rich preparation, which consisted mostly of crater-like bodies with some fragment of cell wall, was easily obtained from the isolated cell walls of baker's yeast by enzymic treatment under appropriate condition. In spite of low glucosamine content, which is due to the action of chitinase in the enzyme preparation, X-ray diffraction analysis showed that the structure of chitin was well preserved in this preparation. On the other hand, the preparation obtained by chemical treatment of intact yeast cells indicated high glucosamine content. Differing from the results of Bacon et al., the present preparation obtained after 2 cycles of chemical treatment still retained the original cellular shape with remnant cytoplasmic materials. After 5 cycles of the treatment, bud scar-rich fraction nearly equal to that obtained by enzymic treatmet was obtained. By the treatment of the bud scar-rich preparation with chitinase, the characteristic annular structure disappeared with concomitant decrease of glucosamine content, and at the same time, stainability with fluorescent dye, Brightener, of the annular structure disappeared. It was concluded that chitin is the intrinsic entity which constitutes the annular structure of the bud scar region and can be stained with Brightener. The appearance of stainable structures and buds together with the increase in cellular content of glucosamine was observed during culture of age 0 cells. The emergence of buds was preceded by the appearance of the stainable structures ; the increase of glucosamine content proceeded in accordance with the appearance of the annular structure. The morphological basis of the budding was discussed with special reference to the role of the annular structure.
Growing cultures and washed mycelium of Trichoderma viride produced acrylate and acetate from allyl alcohol. Acrylate accumulating in mycelial suspensions accounted for about half of the allyl alcohol utilized. Postulated intermediates of α- and β-oxidative pathways were not oxidized when added to washed suspensions; oxygen consumption exceeded the endogenous level in the presence of malonic semialdehyde but this was attributed to ethanol in the preparation. Ethanol and allyl alcohol were oxidized at similar rates; arsenite inhibited oxidation of both alcohols and oxo-acids accumulated. Arsenite-inhibited mycelium oxidizing allyl alcohol accumulated 3 to 5 times as much pyruvate as similar mycelium oxidizing ethanol; smaller amounts of 2-oxoglutarate accumulated in suspensions oxidizing ethanol or endogenous substrates but only trace amounts in those oxidizing allyl alcohol. These results indicate that Trichoderma viride metabolizes allyl alcohol via acrylate and the α-oxidative pathway.
The effect of indoleacetic acid (IAA), gibberellic acid (GA), kinetin, 2, 4, 5- trichlorophenoxyacetic acid (2, 4, 5-T) (1-10ppm) and morphactin (25- 250ppm) on growth of rhizobia was studied in vitro. IAA and Morphactin were inhibitory at all concentrations tried, whereas 2, 4, 5-T and kinetin showed inhibition only at higher concentrations. Gibberellic acid stimulated the growth of Rhizobium up to 8ppm level.
From the cells of 142 strains of the genera Rhodotorula, Cryptococcus, Sporobolomyces, and Rhodosporidium, coenzyme Q (Co-Q) was extracted and partially purified by thin-layer chromatography. The type of Co-Q was mainly determined by paper chromatography. The Co-Q system of these organisms, which were considered to have a phylogenetic relationship to Basidiomycetes, was characterized by the dominant distribution of Q10. An exceptional distribution of Q9 was found in several strains of Rh. glutinis whose perfect stage is Rhodosp. toruloides, Rh. glutinis var. rufusa, Rh. lactosa, Cr. neoformans var. uniguttulatus, Cr. luteolus, and Rhodosp. malvinellum. Rhodotorula infirmo-miniata was the only species with Q8. The genus Rhodosporidium was divided into two groups composed of Q10 and Q9 possessors on the basis of their Co-Q system. These results are discussed in connection with other criteria such as serological characteristics and DNA base composition.