Ralph A. Slepecky

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The phylogeny of 11 pigmented, aerobic, spore-forming isolates from marine sources was studied. Forty-two biochemical characteristics were examined, and a 16S rDNA sequence was obtained for each isolate. In a phylogenetic tree based on 16S sequencing, four isolates (NRRL B-14850, NRRL B-14904, NRRL B-14907, and NRRL B-14908) clustered with B. subtilis and(More)
Phenotypic plasticity in fungi is reviewed in the context of observations on phenotypic changes in the colony morphology of the fungus Aureobasidium pullulans. The variation in colony form is shown to depend on (i) the types of single carbon substrates (sugars and sugar alcohols) used in the growth medium, (ii) colony age, (iii) incubation temperature, (iv)(More)
LAW, JOHN H. (Harvard University, Cambridge, Mass.) AND RALPiH A. SPLEPECKY. Assay of poly-,B-hydroxybutyric acid. J. Bacteriol. 82:33-36. 1961-A convenient spectrophotometric assay of bacterial poly-,B-hydroxybutyric acid has been devised. Quantitative conversion of poly-,B-hydroxybutyric acid to crotonic acid by heating in concentrated sulfuric acid and(More)
Commitment to sporulation was examined by means of both endotrophic sporulation and rejuvenation experiments. In both cases, a point of commitment to the completion of sporulation occurred at stage II. With 2 x 108 cells/ml, the process by which commitment occurred required 0.5 mm Mg2+, 10.0 mm phosphate, and an energy source (minimum of 5.0 mm acetate).(More)
The techniques of Nomarski interference contrast microscopy and phase-contrast microscopy were compared for their utility in monitoring sporulation and germination in Bacillus megaterium. The Nomarski technique permitted rapid and easy delineation of septation and engulfment during sporulation, whereas with phase contrast microscopy these stages were not(More)
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