Lipids were extracted from the cells of Candida lipolytica grown on pure n-hexadecane and on glucose media. The average free lipids produced from each substrate was 7.2% and 7.8% of cellular dry weight, respectively. Free lipids from the cells grown on each substrate were resolved into 7 fractions by thin-layer chromatography. Quantitative techniques showed that the growth substrate affected the chemical composition of the free lipids. Phospholipids of C. lipolytica grown on n-alkane and on glucose media consisted of, at least, seven different components. These are phosphatidic acid, cardiolipin, phosphatidylglycerol, glycophospholipid (glucose is the sugar base), cephalin, lecithin, and sphingomyelin.
The respiratory activities of Saccharomyces cerevisiae requiring pantothenic acid were found to be decreased by deficiency of this acid. Respiration rate of the cells grown in a pantothenic acid-deficient medium decreased to about 1/15, and conversely hydrogen sulfide evolved at log phase was about 10 times that of the normal cells. The decrease of respiration rate was more significant than the repressed cells grown in a 5% glucose medium. These deficient cells had decreased cytochrome content and especially lacked cytochromes a+a3 and b. Except for the activity of cytochrome oxidase, the activities of enzymes containing heme, such as cytochrome c peroxidase and catalase, were not affected. The specific activities of enzymes concerning the initial step of the biosynthesis of porphyrin were also not affected. Cytochrome oxidase, being a mitochondrial particulate enzyme, was drastically influenced by the pantothenic acid deficiency. This effect was peculiar to cytochrome oxidase and more effective than the glucose repression.
Following the previous chemostat cultures of Azotobacter vinelandii using glucose as the sole carbon source, another work, replacing glucose with acetate, is presented in this paper. The experimental fact here that RQ values were from 0.6 to 0.8 in a range of dilution rate D, extending from 0.114 to 0.327hr-1, suggests that glyoxylate cycle as an anaplerotic pathway predominates over tricarboxylic acid cycle. The yield factor for acetate, YX/S g cell/g acetate, decreased from 0.15 to 0.06 with an increase in dissolved oxygen concentration, [D.O.], in an acetate medium. The inhibitory effect of [D.O.] on the YX/S values was similar to that in the previous study on glucose. However, the value of YX/S for acetate was smaller than that for glucose. Assuming that the value of YATP is constant, irrespective of acetate or glucose, the difference in YX/S values between the carbon sources was ascribed to that in moles of ATP required to phosphorylate one gram of acetate and glucose.
Aspergillus oryzae conidia germinate with good synchrony in a modified Czapek's medium supplemented with L-alanine and adenine. The present report deals with the role of adenine in the process of germination. Exogenous adenine is required only transiently during a period of 40-90 min after inoculation. 14C-Adenine incorporation experiments showed that inosine, AMP, ATP, and NAD comprised nearly 90% of radioactivity in the acid-soluble fraction. Incorporation of 14C-adenine into RNA was accelerated markedly in this transient period. The rate of subsequent protein synthesis was retarded if adenine was not added during the transient period. The present data suggest that the exogenous adenine serves as one of the initiation factors for vegetative growth but not as a trigger for germination.
Aerobically grown cells of Escherichia coli contained several times as much cytochrome b1, cytochrome d, and protoheme as anaerobically grown cells. The activity for the synthesis of δ-aminolevulinic acid (ALA) from succinate and glycine was remarkably higher in aerobically than in anaerobically grown cells. Incubation of anaerobically grown cells for 4hr with ALA under either aerobic or anaerobic condition resulted in the synthesis of protoheme, but the aerobic incubation was more favorable for the heme formation. By prolonged aeration of anaerobically grown cells with ALA, porphyrins were accumulated inside and outside of the cells. If casamino acids were supplemented to the incubation mixture containing ALA, the aerobic protoheme formation was much more pronounced, and the heme synthesis was partly inhibited by chloramphenicol and by puromycin. Accompanied with the formation of protoheme by the aerobic incubation of anaerobically grown cells, a cytochrome-type pigment, which could be reduced by succinate or NADH and oxidized by air, accumulated in the cells. The reduced spectrum of the pigment showed peaks identical with those of cytochrome b1, but the shape of the absorption curve was not the same as that of the cytochrome. These results, and previous findings, reveal that the effect of oxygen on the formation of heme and cytochrome in E. coli is manifold; oxygen enhances (1) the formation of enzymes for succinyl-CoA synthesis, (2) formation of enzymes in some step between ALA and protoheme, (3) the reaction of preformed enzymes in some step between ALA and protoheme (probably the conversion of coproporphyrinogen to protoporphyrin), and possibly (4) the formation of ALA synthetase. In addition, oxygen may affect the formation of apoprotein moiety of cytochromes.
Fifty-four bacterial strains were isolated from the Tongariro National Park activated sludge. Of these, only 4 strains were capable of forming floc in proteose peptone-yeast extract (PPYE) but 6 strains of Pseudomonas sp. produced floc in synthetic sewage. The activated sludge was easily reconstructed by mixing the isolated bacteria at random. The chemical oxygen demand (COD) removal activities of these reconstructed sludges were twice as much as that of the original activated sludge. The reconstructed activated sludges from the pure cultures had almost the same activity as the original activated sludge. Sugar components, from NH3-extracted fraction of the activated sludge polymer, were mainly glucose, and minor quantities of pentose and glucuronic acid; but those from EDTA-extracted fraction were mainly glucuronic acid and small amount of glucose and pentose.
A description has been given of a new species of yeast, Debaryomycesformicarius. The natural habitat of this new species is the ant-hills of ants of the group Formica rufa L. In these ant-hills another species of yeast, Debaryomyces cantarellii, was constantly occurring.