Ten strains of yeast isolated from the oil fields of Assam in India and identified as Endomycopsis lipolytica were studied. The characteristics of the growth of these ascosporogenous yeast strains on various petroleum fractions and n-alkanes are reported for the first time.
Various floc-forming bacteria isolated from activated sludge were found to form capsular matrix or extracellular fibrils around the cells. Such extracellular materials were susceptible to cellulase, pectinase, or protease, and deflocculation was observed after treatment by these enzymes. The cellulase- susceptible floc-forming bacterium was identified as Bacillus cereus. while the protease-susceptible one was identified as Flavobacterium dormitator which has not been observed as a floc-former thus far. Among the isolated bacteria, Corynebacterium fascians was also identified as a new floc-former. It is postulated that the extracellular polymers are responsible for the flocculent growth habit of bacteria.
The growth of Arthrobacter simplex IFO 12069 is specifically inhibited by citrate but not by isocitrate or cis-aconitate in the glucose basal medium. Citrate binds to the cell surface and inhibits glucose permeation of this organism.
Four new yeasts, Pichia nonfermentans, Candida boleticola, Candida butyri, and Candida quercuum, were described on the basis of taxonomic characteristics commonly employed and the base composition in DNA.
The development in respiratory activity for several substrates during the aeration of anaerobically grown Escherichia coli was inhibited by fluoroacetate (FAA), but the inhibition was lessened if formate was further added to the aeration medium. During an aeration with FAA and formate, an enormous increase in the activity of aconitase was observed; under the anaerobic incubation aconitase activity did not show significant increase. The addition of FAA after a certain period of aeration induced a rapid increase in aconitase activity. Aeration before the addition of FAA made subsequent increase of the enzyme activity under anaerobic condition possible. The increase of aconitase activity- during the aeration of anaerobic cells with FAA was repressed by chloramphenicol or by the starvation of cells for amino acids. In pre-aerated cells, however, subsequent increase of enzyme activity by the addition of FAA was not inhibited by chloramphenicol or puromycin, and also not repressed by the starvation of cells for amino acids. During aeration, citrate accumulation in the cell suspension was caused not only by FAA but also by picolinate. However, the latter did not induce the development of aconitase activity. From these results the role of FAA and formate on the increase of aconitase activity in anaerobically grown cells is discussed.
Streptomycin-resistant or adenine-requiring mutants of Bacillus subtilis may be producers, feeble producers or non-producers, of mycobacillin, an antifungal polypeptide antibiotic, but they all form spores including even the mycobacillin-negative mutants. The spores were characterized by dipicolinic acid content, spore staining, heat resistance (80°, 15min), and germination.
1. Four strains of yeast belonging to Endomycopsis and Saccharomyces species with optimum temperature of growth on hydrocarbons at 37° or more have been isolated. 2. Three more strains belonging to Saccharomyces species which tolerate a temperature of 37° for growth on hydrocarbons have also been described. 3. Growth of these strains at different temperatures and on various petroleum fractions and n-alkanes, and their crude protein content and essential amino acid profile are presented. 4. Use of these strains for production of single cell protein may obviate the necessity for elaborate cooling system for the fermentor.