Bile peptone broth and alkaline peptone water (pH 8.5) were examined as enrichment media for the isolation of Plesiomonas shigelloides from stools, with salmonella-shigella agar as the isolation medium. After 423 parallel examinations in two different experiments, bile peptone broth enrichment for 24 h was observed to be six times more effective (P less than 0.01) than direct plating alone on s...

Starting from 2-(2-pyridyl) imidazole a series of substituted imidazoles (2-5) were prepared. From the reaction of 2-(3-pyridyl) -4-(or 5) nitroimidazole (15) with dimethyl sulfate in alkaline medium 1-methyl-2-(3- pyridy1)-4-nitroimidazole (6,)w as prepared. Reaction of compound 15 with diazomethane gave I-methyl-2-(3-pyridy1)-5- nitroimidazol(e7 ) in addition to 6. The antibacterial and an...

The action potential (AP) of excitable plant cells is a multifunctional physiological signal. Its generation in characean algae suppresses the pH banding for 15-30 min and enhances the heterogeneity of spatial distribution of photosynthetic activity. This suppression is largely due to the cessation of H(+) influx (OH(-) efflux) in the alkaline cell regions. Measurements of local pH and membrane...

The chemiluminescence (CL) accompanying the oxidation of phenyl hydrazine with t-butylhydroperoxide in alkaline medium was studied in the presence and absence of luminol. The reaction occurring between phenyl hydrazine and alkaline (KOH) solution of aqueous tbutylhydroperoxide leads to the production of nitrogen gas with simultaneous emission of light (CL), which has been detected by PMT and re...

The intracellular protease extracted from the freeze-dried mycelia obtained after the growth of Mucor pusillus at 30 degrees C in corn steep liquor medium was chromatographed on DEAE-A50. Some characteristics of the protease fractions obtained after ion-exchange chromatography were determined and compared with those of the extracellular proteases reported previously. The mycelia were found to c...

Background In tissue engineering, scaffold characteristics play an important role in the biological interactions between cells and the scaffold. Cell adhesion, proliferation, and activation depend on material properties used for the fabrication of scaffolds. Objective In the present investigation, we used collagen with proper characteristics including mechanically stability, biodegradability ...

Escherichia coli KG980, a vitamin B6 auxotroph derived from E. coli K12, utilized the three unphosphorylated forms of vitamin B6, more or less effectively, for growth, but did not utilize the three phosphate forms at concentrations ranging from 10(-7) to 10(-5) M in the minimum medium of Davis and Mingioli. The bacterium, however, utilized the phosphate forms, although less effectively than the...

The aim of this study was to investigate the adaptation of the cyanobacterium Fischerella sp. ISC 107to combined effects of carbon dioxide concentration, acidic and alkalinity. Axenic strain was incubated in BG0-11 medium. Carbon dioxide treatments were limited and relatively non-limited. Acidic (pH 5), neutral (pH7), and alkaline (pH 9) conditions were employed in each treatment. Survival, gro...

Depending on the pH of the growth medium, the yeast Yarrowia lipolytica secretes an acidic protease or an alkaline protease, the synthesis of which is also controlled by carbon, nitrogen, and sulfur availability, as well as by the presence of extracellular proteins. Previous results have indicated that the alkaline protease response to pH was dependent on YlRim101p, YlRim8p/YlPalF, and YlRim21p...

Life in oligotrophic environments necessitates quick adaptive responses to a sudden lack of nutrients. Secretion of specific degradative enzymes into the extracellular medium is a means to mobilize the required nutrient from nearby sources. The aquatic bacterium Caulobacter crescentus must often face changes in its environment such as phosphate limitation. Evidence reported in this paper indica...