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W J DOBROGOSZ

Publications and source records attributed to W J DOBROGOSZ.

7 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

Oxidative metabolism in Pediococcus pentosaceus. I. Role of oxygen and catalase.

Dobrogosz, Walter J. (Pennsylvania State University, University Park) and Robert W. Stone. Oxidative metabolism in Pediococcus pentosaceus. I. Role of oxygen and catalase. J. Bacteriol. 84:716-723. 1962.-Studies were conducted on the physiological behavior of several strains of Pediococcus pentosaceus isolated from alfalfa silages. Although these organisms are regarded as homofermentative lactic acid bacteria which metabolize carbohydrates via the classic reactions of glycolysis, this investigation showed that they were capable of developing other physiologically important reactions related to carbohydrate metabolism. Growth on glycerol, for example, was shown to depend on the development of aerobic reactions, and was directly related to the catalase content of the various strains tested. These organisms were shown to be devoid of a cytochrome system, thus implicating an active flavoprotein system in oxidative reactions. A study of the end products of aerobic glycerol metabolism suggested that glycerol was oxidized to the pyruvate level, with subsequent reactions involving pyruvate leading to the accumulation of lactate, acetate, acetoin, and CO(2) in a molar ratio of approximately 1:1:1:3.

Acetates↗
PubMed1962

Oxidative metabolism in Pediococcus pentosaceus. II. Factors controlling the formation of oxidative activities.

Dobrogosz, Walter J. (The Pennsylvania State University, University Park) and Robert W. Stone. Oxidative metabolism in Pediococcus pentosaceus. II. Factors controlling the formation of oxidative activities. J. Bacteriol. 84:724-729. 1962.-Studies were conducted on some factors which regulate the formation of oxidative activities in Pediococcus pentosaceus, a homofermentative lactic acid organism. Oxidative abilities were defined as the capacities to oxidize glucose and glycerol, and to exhibit catalase activity. Factors such as the type of growth substrate, the growth substrate concentration, pH, and oxygen tension were considered. The results suggested that the development of oxidative activities in this organism is under adaptive control and subject to repression by the well-known "glucose effect," as well as by anaerobiosis. In addition to the necessity for the formation of aerobic systems for the metabolism of glycerol, which can be utilized only under aerobic conditions, data are presented which suggest that aerobic reactions may play a physiologically important role toward the induction of growth on other substrates such as d-xylose and lactose.

Carbohydrate Metabolism↗