REACTIONS OF SPORES AND CELLS OF BACILLUS CEREUS WITH PYRIMIDINE RIBOSIDES

Lawrence , N. L. (University of Alabama, Birmingham) and Yun-Chuan Tsan . Reaction of spores and cells of Bacillus cereus with pyrimidine ribosides. J. Bacteriol. 83: 228–233. 1962.—Cytidine deaminase and uridine ribosidase were essentially inactive in heat-resistant spores of Bacillus cereus T, but the activity increased as the spores germinated and proceeded to the vegetative form. The activity of germinated spores on cytidine was evident only after several hours lag, but then was nearly equal to that of vegetative cells. Cytosine deaminase was absent from all these preparations, but deoxycytidine was deaminated at nearly the same rate as cytidine. In the absence of added phosphate, cytidine was converted to uracil by intact vegetative cells more completely than was uridine.

COMPARISON OF GROWTH AND PECTOLYTIC ENZYME PRODUCTION BY BACILLUS POLYMYXA

Nagel, Charles W. (University of California, Davis) and Reese H. Vaughn . Comparison of growth and pectolytic enzyme production by Bacillus polymyxa . J. Bacteriol. 83: 1–5. 1962.—Studies were made of pectolytic enzyme production by Bacillus polymyxa during growth. It was found that elaboration of enzyme occurred during logarithmic growth and ceased when the stationary phase was reached. The specific activity of the extra-cellular enzyme remained relatively constant until lysis occurred. The increased specific activity of the intracellular pectolytic enzyme may be explained if one assumes that the rate of secretion of the intracellular enzyme is dependent upon the concentration of the extracellular enzyme. The concentration of the intracellular pectolytic enzyme dropped markedly at the end of the logarithmic growth phase; the enzyme was released into the medium during the stationary growth phase and subsequent lysis of the cells. It was shown that the intra- and extracellular enzymes were similar or identical in that both were calcium-dependent pectic acid transeliminases.

Assay of poly-beta-hydroxybutyric acid

Law, John H. (Harvard University, Cambridge, Mass.) and Ralph A. Splepecky. Assay of poly-beta-hydroxybutyric acid. J. Bacteriol. 82:33-36. 1961-A convenient spectrophotometric assay of bacterial poly-beta-hydroxybutyric acid has been devised. Quantitative conversion of poly-beta-hydroxybutyric acid to crotonic acid by heating in concentrated sulfuric acid and determination of the ultraviolet absorption of the produce permits an accurate determination of this material in quantities down to 5 mug. This method has been used to follow the production of poly-beta-hydroxybutyric acid by Bacillus megaterium strain KM.