Strong light intensity of the culture broth and industrially feasible cultural conditions are required in order to apply the bioluminescence of luminous bacteria to attracting fish. To obtain strong bioluminescence of the culture broth, studies of the optimum cultural conditions for strong light production by Photobacterium phosphoreum MT-10201 were carried out. Strong light intensity of the culture broth was obtained at an initial NaCl concentration in the medium between 3% and 5.5%, starting pH 8.5, and cultivation temperature 20°. The addition of 0.1% malic acid to the medium resulted in enhanced light intensity of the culture broth but mannose, arginine, dodecylaldehyde, and phosphate buffer used for pH control during cultivation had no effect. Cultivation of the luminous bacterium in 2-liter and 20-liter fermentors was carried out, and luminous raw bait was prepared successfully by using the culture broth directly as a luminous source.
Degradation of macromolecules such as DNA, RNA, protein, and phospholipid in carotovoricin Er-treated cells was examined. No significant decrease in acid-insoluble radioactivity of DNA, RNA, or protein which were labeled with 3H-thymine, 3H-uracil, and 3H-phenylalanine, respectively, could be detected in the carotovoricin Er-treated cells. On the other hand, marked degradation of phospholipids labeled with 2-3H-glycerol was observed in the cells exposed to the bacteriocin. There was a similar decrease in radioactivity of both 3H and 32P in the lipid fraction double-labeled with 2-3H-glycerol and 32PO3-4. This decrease in radioactivity of phospholipids was explained by the release of fatty acid moieties from phospholipids. These results indicate that phospholipid degradation in carotovoricin Er-treated cells is caused by the action of phospholipase A. The amount of fatty acids released from phospholipids was proportional to the number of cells killed by the bacteriocin, suggesting that phospholipase A activity involved in phospholipid degradation is located in the sensitive cells, not in the bacteriocin.
This report describes the isolation of bacteriophages (phages) infectious for dominant bacteria in the activated sludge of a public sewage disposal plant, and the influence of the phages on the bacterial flora and the purification powers (biological oxygen demand [BOD], chemical oxygen demand [COD] and sludge volume index [SVI]) of the sludge. The activated sludge used contained two groups of dominant bacteria, M1-W and M1-P. Their phages were easily found in spring and autumn in the sludge or in the environment around the plant. Eight phages attacking M1-W strains and two phages attacking M1-P strains were isolated during 30 months' investigation. At the time of the isolation of these phages, a disturbance in the normal bacterial flora possibly due to phage infection was observed, as well as a change in dominant strains (for example, when the phage attack on M1-W strains occurred, M1-P strains became dominant). Such disturbance was considered to cause a decrease in the purification powers of the activated sludge.
By using intact cells of the fission yeast Schizosaccharomyces pombe, the derepressed activity of sucrase (EC 3. 2. 1.26), as extracellular enzyme located in the periphery of the yeast, was measured during the cell cycle, with cell length serving as the measure of cell growth. Both specific activity of sucrase and average cell length were constant through asynchronous cultures. Under the same experimental conditions as for asynchronous cultures, the specific activity of sucrase showed a pattern of periodic synthesis after either selection synchronization by the gradient sedimentation method or induction synchronization by pulse treatment with hydroxyurea (HU), an inhibitor of DNA synthesis. On the other hand, the specific activity of sucrase continued to increase exponentially when HU was added to the asynchronous culture or to the selection-synchronous culture, but decreased stepwise in induction- synchronous cultures in a poor medium after selection, in which the cells divided synchronously without cell elongation. The patterns of sucrase activity in all systems were parallel to those for average cell length. These results suggest that the synthesis of sucrase is dependent on the growth in cell length as well as acid phosphatase as we reported in a previous paper (1).
Various properties such as pH optimum, response to metal ions and inhibitors, and heat stability of two extracellular and one intracellular proteases from both parent and asporogenous strains of Bacillus subtilis were examined, and no significant difference between the two strains was observed. The intracellular protease was shown to be a serine protease absolutely requiring Ca2+. We examined in vivo degradation of the cellular protein at the stationary phase in both parent and mutant strains and found that degradation occurred only in the parent strain. Addition of Ca2+ and toluene together to the reaction mixture of the mutant strain, however, resulted in significant degradation of the cellular protein in the mutant strain, although the addition of either Ca2+ or toluene alone had no stimulating effect on the degradation. These results suggest that the mutant strain is defective in its transport system for Ca2+.
Thirty-one freshly isolated strains of methanol-assimilating yeasts were identified as Pichia cellobiosa (3 strains), Candida boidinii (20 strains), Candida cariosilignicola (1 strain), Candida succiphila (6 strains), and Torulopsis molischiana (1 strain). Kloeckera sp. No. 2201 and Candidamethanolica, which were reported as methanol-assimilating yeasts, and Candida koshuensis were reidentified as C. boidinii on the basis of biological and chemotaxonomic characteristics. Torulopsis methanolovescens showed characteristics similar to those of Pichia lindnerii, and the chemotaxonomic characteristics of the two were in good agreement. The DNA base composition (GC-content of DNA) of these yeasts was distributed in a broad range from 29.2% to 50.2%. The ubiquinone system, proton magnetic resonance spectra of cell-wall mannans, and electrophoretic patterns of methanol oxidase were characteristic for each species. These methanol-assimilating yeasts were divided into four groups: 1) the C. boidinii group, 2) methanol-assimilating Hansenula and its closely related yeasts, 3) the P. cellobiosa group, and 4) the Hansenulacapsulata group.
A small amount of water-soluble fructan (F) was formed from sucrose by 71 strains of Bacillus laevolacticus (I) and some strains of Sporolactobacillusinulinus. A gelatinous mass of water insoluble glucan (G), together with F, was formed from sucrose by a few strains of I. Polysaccharide formation was not observed in such groups of spore- bearing lactic acid bacteria as Bacillus coagulans, Bacillus racemilacticus and racemic lactic acid-producing Sporolactobacillus. Aeration was not needed for the formation of either F or G. Yield of G was up to 25% from sucrose and 2% from yeast extract-peptone broth with 8% sucrose. G was solubilized in 0.1N sulfuric acid by heating at 100° for 20min, and the solubilized G (SG) was partially hydrolyzed by dextranase. Molecular weights of SG and F were about 6.4×105 and more than 2×107, respectively. Antitumor activity of both SG and F against mouse Sarcoma 180 was about 60%.
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)