An HPLC method has been developed to quantify and compare the relative amounts of minor and major coenzymes Q within and between different yeast species and under different cultural conditions. Four control yeast species were studied: Pichia rhodanensis (Q7), Pichia methanolica (Q7 and Q8), Pichia inositovora (Q9), and Rhodotorula glutinis (Q10). The glucose concentration in the culture medium moderately affected the minor peaks of coenzymes Q as did the duration of the coenzyme Q extraction. But the culture age was the main influence on minor and major coenzymes Q. A careful standardization of growth conditions is required to obtain significant and comparative results from one species to another.
A three-variable product-inhibition model of a continuous fermentation process is considered. It is shown that as time progresses all solution trajectories in the three-dimension solution space approach a plane and thus the three-variable system is equivalent to a model involving only two variables. With this result, we are able to obtain the stability condition for limit cycles bifurcating from a non-washout steady state of the three-variable model, and at the same time rule out the possibility of developing chaotic trajectories through subsequent bifurcations.
Some strains in the genus Monascus secreted extracellular alkaline proteinases on a wheat bran medium, along with propagation of cells. Crude enzymes prepared from six strains of five species and one variety of Monascus were separated by polyacrylamide slab gel electrophoresis and their activities were visualized with a printing technique on a casein-containing gel. We found that their proteinase activities were based on at least three different proteins which occurred commonly in all the strains examined. These enzymes were completely inhibited by phenylmethylsulfonyl fluoride and were insensitive to chelating and SH reagents. They were characterized as serine proteinases different from chymotrypsin- or trypsin-type enzymes by their insensitivity to the affinity-labeling reagents, N-α-tosyl-L-lysyl chloromethyl ketone and N-tosyl-L-phenylalanyl chloromethyl ketone.
A new genus Ballistosporomyces Nakase, Okada et Sugiyama in the Hyphomycetes is described for yeasts that reproduce by both non-ballistosporous conidia and ballistospores, but not by budding yeast cells. Non-ballistosporous conidia are produced on a sterigma-like stalk which proliferates sympodially or percurrently. Strains in this genus have Q-10 as the major isoprenologue of ubiquinone, do not contain xylose in the cells, and show positive Diazonium blue B reaction. Two new species, Ballistosporomyces xanthus (type species) and B. ruber, are described in the genus. Ballistosporomyces xanthus has a G+C content of DNA of 62.1mol% and forms yellow colonies, whereas B. ruber has a G+C content of DNA of 50.8mol% and forms red colonies. Some properties of the new genus indicate a Ustilaginale affinity. Ontogenetic and chemotaxonomic comparisons are made between Ballistosporomyces and other supposedly related basidiomycetous yeast genera.
The menaquinone composition of Micrococcus luteus strains grown in different media was examined. Cells of M. luteus IAM 1056 (type strain) grown in an ordinary complex medium contained MK-8 as the predominant menaquinone. On the other hand, this bacterium produced both MK-8 and MK-8(H2) as major quinones when grown in a chemically defined medium containing glutamate and pyruvate as carbon sources. Unlike the type strain, M. luteus strains IAM 12009 and IAM 12144 had MK-8 (H2) as the major menaquinone, independent of cell growth media. In all strains the total amount of dihydrogenated homologs relative to the total menaquinone content increased more or less in cells grown in the chemically defined medium. Carbon sources and Mg2+ concentrations in the growth medium had minor effects on the menaquinone composition of the M. luteus strains.
We examined the effect of the pesticides Furadan (Carbofuran, 3%), Sevin (Carbaryl, 50%), Rogor (Dimetnoate, 30% EC) and Endotaf (Endosulfan, 35% EC) on the survival, growth, photosynthetic oxygen evolution and nitrogen fixation of the cyanobacterium Westiellopsis prolifica. Lower concentrations of the carbamate and organophosphate pesticides (10ppm) increased the growth and nitrogen fixation while higher concentrations (>20ppm) had an inhibitory effect. The organochlorine pesticide Endotaf was toxic even at 10ppm. Survivability and nitrogen fixation of the cyanobacterium was reduced to 72 and 93% respectively in the presence of 100ppm of Endotaf. An exposure of the filaments to over 100ppm of Furadan, Sevin or Rogor caused about a 40% inhibition of the photosynthetic oxygen evolution. Endotaf was more toxic than the other pesticides. Oxygen evolution was totally suppressed after incubation of the organism with over 250ppm of Endotaf; there was similar suppression of O2 evolution on treatment with more than 500, 1, 000, and 1, 500ppm of Rogor, Sevin and Furadan respectively. Various cyanobacterial species occur abundantly in rice-fields of tropical and sub-tropical countries, whose agricultural technologies involve extensive use of pesticides for selective elimination of pests of rice crops (1, 3, 8, 14). Therefore, the indiscriminate use of pesticides may be causing adverse effects on these rice-field nitrogen-fixing cyanobacteria which have a direct influence on the total productivity.
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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)