Improved techniques for dissociating particle-associated mixed ruminal microorganisms from ruminal digesta solids.

Combinations of physical and chemical methods were evaluated for their ability to remove particle-associated microorganisms (PAM) from saline-washed ruminal digesta solids (SWRDS). Physical methods included chilling and storage, homogenization, multiple extraction, and agitation with marbles. Chemical methods included use of low pH, Tween 80, formaldehyde, methanol, tertiary butanol, and methylcellulose.

Electro-transformation of Clostridium beijerinckii NRRL B-592 with shuttle plasmid pHR106 and recombinant derivatives.

Conditions for transformation of the solventogenic anaerobe Clostridium beijerinckii NRRL B-592 with plasmid DNA via electroporation are described. Shuttle plasmid pHR106 and two derivatives constructed in this study were transferred and were expressed in this organism. One recombinant derivative of pHR106 was constructed by separately subcloning the clostridial tetracycline (tetP) resistance genes into pHR106.

The domains of slow bacterial growth.

Commonly used culture systems, e.g., batch culture and the chemostat, work poorly for defining the behavior of slowly growing bacteria, i.

Integration of the Vwa plasmid into the chromosome of Yersinia pestis strains harboring F' plasmids of Escherichia coli.

Conditional virulent strains of Yersinia pestis were used as recipients of an F-lac plasmid from either Escherichia coli 23.10S or E. coli CSH23.

Eubacteria have 3 growth modes keyed to nutrient flow. Consequences for the concept of maintenance and maximal growth yield.

Aerobic growth of Escherichia coli and Paracoccus denitrificans has been studied in chemostat, fed batch, and recycling fermentor modes under carbon and energy limitation. Two abrupt drops or discontinuities in molar growth yield, Y, have been found that occur over relatively short ranges in the value of specific growth rate. Before the first discontinuity, Y is constant and maximal.

Very slow growth of Escherichia coli.

A recycling fermentor (a chemostat with 100% biomass feedback) was used to study glucose-limited behavior of Escherichia coli B. The expectation from mass transfer analysis that growth would asymptotically approach a limit mass determined by the glucose provision rate (GPR) and the culture's maintenance requirement was not met. Instead, growth proceeded at progressively lower rates through three distinct phases.

Heterogeneity of Staphylococcus aureus enterotoxin B as a function of growth stage: implications for surveillance of foods.

Staphylococcus aureus was grown in a fermentor under controlled conditions of pH, oxygenation, and temperature, while the higher-molecular-weight products of its growth were continuously removed across ultrafiltration membranes. These products were examined by single and double gel diffusion and immunoelectrophoresis against a variety of available anti-enterotoxin B antisera. All antisera examined were polyvalent for S.

Klebsiella pneumoniae and Staphylococcus aureus infection in mice: difference in uremia and ammoniagenesis.

Lethal infections by Staphylococcus aureus and Klebsiella pneumoniae were compared for kidney-related effects in mice. K. pneumoniae caused uremia and an increase in blood ammonia that could reach 2.

Detection of staphylococcal nuclease elaborated during lethal infections in mice.

Active staphylococcal nuclease was detected in tissues of lethally infected mice. Organ distribution and levels of the enzyme varied with the bacterial strain used.

Beta hemolysin: a persistent impurity in preparations of staphylococcal nuclease and enterotoxin.

Purified staphylococcal nuclease and enterotoxin B from several sources contained beta hemolysin whose physicochemical resemblances to the other two proteins make its elimination difficult.

Carotenoids in yellow-pigmented enterococci.

Pigments extracted from three strains of yellow enterococci showed the spectral and solvent partition characteristics of carotenoids. An unusual C(32) carotenoid aldehyde appears to predominate.

Characteristics of secretion of penicillinase, alkaline phosphatase, and nuclease by Bacillus species.

The distribution of alkaline phosphatase and nuclease activity between cells and medium was examined in one strain of Bacillus licheniformis and four strains of B. subtilis. Over 95% of both activities was found in the medium of the B.

Enzymatic detection of the growth of Staphylococcus aureus in foods.

A specific method has been developed for the extraction and measurement of staphylococcal nuclease in foods in which Staphylococcus aureus has grown. The method was used to compare staphylococcal growth with nuclease production in foods under varying conditions of temperature, aerobiosis, and competition from other microorganisms. It was concluded that the nuclease is produced under any conditions that permit growth of S.

PURIFICATION OF STAPHYLOCOCCAL BETA-HEMOLYSIN AND ITS ACTION ON STAPHYLOCOCCAL AND STREPTOCOCCAL CELL WALLS.

Chesbro, William R. (University of New Hampshire, Durham), Fred P. Heydrick, Roland Martineau, and Gail N.