Biomedical subjects

W W UMBREIT

Publications and source records attributed to W W UMBREIT.

At least 19 recordsLinked to original sources

PubMed1965

EFFECT OF BIOTIN ON FATTY ACID DISTRIBUTION IN ESCHERICHIA COLI.

Gavin, John J. (Rutgers, The State University, New Brunswick, N.J.), and Wayne W. Umbreit. Effect of biotin on fatty acid distribution in Escherichia coli. J. Bacteriol. 89:437-443. 1965.-Biotin deficiency causes changes in the composition and distribution of the fatty acids in cell wall-cell membrane fractions of Escherichia coli T 94A. Most notable among the fatty acid changes are decreased amounts of unsaturated fatty acids, the presence of unsaponifiable lipid material, and the lack of a lipopolysaccharide fraction in the cell wall-cell membrane. Also, though the hexane-extractable material from the lipoprotein fraction of biotin-adequate cells will transfer glucose from water to hexane, the same material from biotin-deficient cells will not.

Biochemical Phenomena↗

PubMed1964

FACTORS WHICH MODIFY THE EFFECT OF SODIUM AND POTASSIUM ON BACTERIAL CELL MEMBRANES.

Henneman, Dorothy H. (Rutgers, The State University, New Brunswick, N.J.), and W. W. Umbreit. Factors which modify the effect of sodium and potassium on bacterial cell membranes. J. Bacteriol. 87:1266-1273. 1964.-Suspensions of Escherichia coli B, when placed in 0.2 to 0.5 m solutions of NaCl, KCl, or LiCl, show an increased turbidity. With NaCl, this increased turbidity is stable with time; with KCl and LiCl, it is gradually lost. The stability to NaCl with time is due to substances removable from the cell by incubation in phosphate buffer; these materials exist in water washings from such phosphate-incubated cells.

Bacteria↗

PubMed1964

INFLUENCE OF THE PHYSICAL STATE OF THE BACTERIAL CELL MEMBRANE UPON THE RATE OF RESPIRATION.

Henneman, Dorothy H. (Rutgers, The State University, New Brunswick, N.J.), and W. W. Umbreit. Influence of the physical state of the bacterial cell membrane upon the rate of respiration. J. Bacteriol. 87:1274-1280. 1964.-NaCl and KCl in concentrations of the order of 0.2 to 0.5 m inhibit the respiration of Escherichia coli B and other gram-negative organisms. Cell-free enzymes concerned in respiration and prepared from the same organisms are not inhibited by these salts, whereas these same enzymes tested in intact cells are. The physical state of the cell membrane appears to be a factor controlling its respiratory activity.

Bacteria↗

PubMed1964

UTILIZATION OF AROMATIC AMINO ACIDS BY HYDROGENOMONAS FACILIS.

DeCicco, B. T. (Rutgers, The State University, New Brunswick, N.J.), and W. W. Umbreit. Utilization of aromatic amino acids by Hydrogenomonas facilis. J. Bacteriol. 88:1590-1594. 1964.-An auxotrophic mutant of Hydrogenomonas facilis was isolated which requires tryptophan, phenylalanine, and p-aminobenzoic acid (PABA) for growth. With glucose as the main carbon and energy source, the quantitative requirements for tryptophan and PABA were at normal microgram levels, but the requirement for phenylalanine was very large and approached substrate concentrations. The large phenylalanine requirement is due to a rapid oxidation and degradation of phenylalanine by the mutant. The utilization of both phenylalanine and glucose is adaptive, and the presence of phenylalanine partially inhibits the induction of the glucose-utilizing system. Wild-type H. facilis can utilize either phenylalanine or tyrosine for growth. Tracer studies indicated that during growth on phenylalanine, the aromatic ring is opened and degraded. Wild-type cells grown on either phenylalanine or tyrosine can oxidize phenylalanine, tyrosine, or phenylpyruvate without a lag. Another inducible pathway enables H. facilis to utilize either quinate or 3,4-dihydroxybenzoate for growth, and sequential adaptation studies revealed that quinate is converted to 3,4-dihydroxybenzoate during its degradation. Mutants may be obtained which can also utilize 2,5-dihydroxybenzoate for growth.

4-Aminobenzoic Acid↗

PubMed1963

Attachment of Thiobacillus thiooxidans to sulfur crystals.

Schaeffer, W. I. (Rutgers, The State University, New Brunswick, N.J.), P. E. Holbert, and W. W. Umbreit. Attachment of Thiobacillus thiooxidans to sulfur crystals. J. Bacteriol. 85:137-140. 1963.-Electron micrographs of replicas of sulfur crystals before and after attack by Thiobacillus thiooxidans show that the microorganisms erode the crystal in the area immediately adjacent to the cell. When there are many cells, the entire crystal surface appears eroded.

Acidithiobacillus thiooxidans↗

PubMed1963

Influence of streptomycin on nucleotide excretion in Escherichia coli.

Tzagoloff, Helen (Rutgers, The State University, New Brunswick, N.J.) and W. W. Umbreit. Influence of streptomycin on nucleotide excretion in Escherichia coli. J. Bacteriol. 85:49-52. 1963.-The action of streptomycin in causing nucleotide excretion is not the cause of the killing effect of streptomycin, because, in certain strains, streptomycin may kill the cells without evidence of nucleotide excretion. In readily excreting strains, most of the cells are killed before nucleotide excretion is evident.

Escherichia coli↗

PubMed1963