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R D DEMOSS

Publications and source records attributed to R D DEMOSS.

At least 19 recordsLinked to original sources
PubMed1963

INDUCTION AND REPRESSION OF L-ARABINOSE ISOMERASE IN PEDIOCOCCUS PENTOSACEUS.

Dobrogosz, Walter J. (University of Illinois, Urbana) and Ralph D. DeMoss. Induction and repression of l-arabinose isomerase in Pediococcus pentosaceus. J. Bacteriol. 85:1350-1355. 1963.-The inducible l-arabinose isomerase of Pediococcus pentosaceus can be rapidly and conveniently measured in whole-cell preparations by use of a standard colorimetric procedure originally developed for studies with cell-free enzyme preparations. The enzyme is measured by its ability to catalyze the isomerization of l-arabinose to l-ribulose. Whole cells suspended in a suitable buffer and pretreated with toluene were shown to exhibit this isomerase activity at a level comparable with that observed in cell-free enzyme preparations. Conditions for optimal induction of l-arabinose isomerase are described. In addition, it was determined that the formation of this enzyme is subject to repression by glucose, i.e., via catabolite repression.

Aldose-Ketose Isomerases↗
PubMed1963

PENTOSE UTILIZATION BY PEDIOCOCCUS PENTOSACEUS.

Dobrogosz, Walter J. (University of Illinois, Urbana) and Ralph D. DeMoss. Pentose utilization by Pediococcus pentosaceus. J. Bacteriol. 85:1356-1364. 1963.-Data are presented which indicate that pentoses are metabolized by Pediococcus pentosaceus through the use of an inducible phosphoketolase pathway. The utilization of each of the pentoses (l-arabinose, d-ribose, and d-xylose) appears to involve a different regulatory process. Thus, d-ribose was fermented by cells grown on any pentose or glucose, although growth on a pentose resulted in an increased ribose-fermenting capacity. l-Arabinose fermentation was only observed when cultures were grown in the presence of this pentose. Similarly, d-xylose fermentation was a specific response to the presence of xylose in the growth medium. In this case, however, growth occurred only at a very low rate unless another readily utilizable substrate (in low concentration) was added to the growth medium. Under these conditions, an aerobic atmosphere was more stimulatory than anaerobiosis for induction and growth on xylose. The possible cryptic nature of xylose utilization in this organism is described.

Aldehyde-Lyases↗
PubMed1962

Glycolytic enzymes in Zymomonas mobilis.

Raps, Shirley (University of Illinois, Urbana) and R. D. DeMoss. Glycolytic enzymes in Zymomonas mobilis. J. Bacteriol. 84:115-118. 1962-An enzyme extract of Zymomonas mobilis (Pseudomonas lindneri) was capable of fermenting glucose-6-phosphate to CO(2) and ethanol. The extract was found to contain phosphohexoisomerase, aldolase, and glyceraldehyde-3-phosphate dehydrogenase, but no demonstrable phosphohexokinase. The lack of isotope-mixing found in earlier studies is, thus, explained on an enzymatic basis.

Bioreactors↗