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H C LICHSTEIN

Publications and source records attributed to H C LICHSTEIN.

At least 19 recordsLinked to original sources
PubMed1965

CONVERSION OF D-BIOTIN TO BIOTIN VITAMERS BY LACTOBACILLUS ARABINOSUS.

Birnbaum, Jerome (University of Cincinnati College of Medicine, Cincinnati, Ohio), and Herman C. Lichstein. Conversion of d-biotin to biotin vitamers by Lactobacillus arabinosus. J. Bacteriol. 89:1035-1040. 1965.-Saccharomyces cerevisiae utilizes d-biotin, biotin sulfoxide, and several vitamers of biotin, whereas Lactobacillus arabinosus responds to biotin and biotin sulfoxide of the naturally occurring forms of the vitamin. The use of these organisms for differential assay permitted investigation into possible conversion of d-biotin to vitamers of biotin by cells of L. arabinosus. Cells were grown in modified Wright-Skeggs medium containing several levels of biotin. No differences were detected between the assays for free intracellular or bound biotin up to 48 hr of growth. However, at 15 to 16 hr, in media containing an excess of biotin, the lactobacillus assay value for menstruum biotin dropped markedly, whereas the yeast assay showed no change. This suggested that biotin was converted to vitamers not active for L. arabinosus. The biotin-converting system appears to have characteristics of an enzyme system, i.e., a temperature optimum at 37 C, a broad pH optimum of 4.3 to 6.5, and requirements for Mg and Mn ions. Experiments suggest that increasing hydrogen ion concentration is a major physiological mechanism controlling the formation of this system. The vitamers were separated chromatographically and were found to have R(F) values of 0.44 and 0.94, and are combinable and uncombinable with avidin, respectively. The physiological role of biotin conversion is discussed in relation to control of cell populations in cultures of L. arabinosus.

Biological Assay↗
PubMed1965

REPRESSION OF TRYPTOPHANASE SYNTHESIS IN ESCHERICHIA COLI.

Beggs, William H. (University of Cincinnati, Cincinnati, Ohio), and Herman C. Lichstein. Repression of tryptophanase synthesis in Escherichia coli. J. Bacteriol. 89:996-1004. 1965.-The nature of the glucose effect on tryptophanase in Escherichia coli (Crookes) was investigated to test the catabolite-repression hypothesis. Under static conditions of growth in the presence of 0.005 m glucose, tryptophanase was repressed and remained so upon continued static incubation subsequent to glucose exhaustion. Aeration following glucose exhaustion under static cultural conditions resulted in rapid enzyme synthesis. In the absence of glucose, certain amino acids repressed tryptophanase synthesis early in the growth cycle under aerated conditions. An inverse relationship was observed between the concentration of acid-hydrolyzed casein and the level of tryptophanase. At 3 hr, enzyme activity in cells grown in media containing 0.05% acid-hydrolyzed casein was at least five times that of cells grown in the presence of 1% casein. Addition of 0.005 m d- or l-serine to a 0.05% acid-hydrolyzed casein medium rendered the medium capable of strongly repressing tryptophanase. Glucose-expended medium was prepared by allowing cells to grow and exhaust glucose in static culture. When this expended medium was recovered and inoculated with fresh cells not previously exposed to glucose, tryptophanase synthesis was repressed for a short period in shake culture, but in static culture enzyme synthesis was only slightly affected. When the expended medium was prepared from shake cultures, fresh cells were not repressed strongly when subsequent incubation was carried out aerobically. The tryptophan pool in glucose-repressed cells grown in shake culture was appreciably less than in cells grown in the absence of glucose or in cells undergoing synthesis of tryptophanase after exhaustion of the sugar.

Amino Acids↗
PubMed1963

EFFECT OF TWEEN 80 ON THE GROWTH OF TUBERCLE BACILLI IN AERATED CULTURES.

Lyon, Richard H. (Veterans Administration Hospital, Minneapolis, Minn.), Herman C. Lichstein, and Wendell H. Hall. Effect of Tween 80 on the growth of tubercle bacilli in aerated cultures. J. Bacteriol. 86:280-284. 1963.-The effect of Tween 80 (polyoxyethylene sorbitan monooleate), glucose, and glycerol on aerated and stationary growth of Mycobacterium tuberculosis strain H(37)Ra was examined in Dubos liquid medium. Previous studies established that aeration (rotation) of liquid cultures of M. tuberculosis strains H(37)Ra and H(37)Rv caused an inhibition of growth in a medium containing glucose as a source of carbohydrate. The present studies show that Tween 80 exerts a toxic effect on the growth of tubercle bacilli in aerated cultures when glucose is present in the medium as the sole source of carbohydrate, but not when glycerol is included. The role of hydrolytic products of Tween 80, viz. oleic acid and the polyoxyethylene derivative of sorbitol, is discussed. The hypothesis is submitted that glycerol protects against the growth suppression by aeration because it reduces the concentration of free fatty acids in the medium to subinhibitory levels.

Bacillus↗
PubMed1962

Tryptophanase-tryptophan synthetase systems in Escherichia coli. I. Effect of tryptophan and related compounds.

Freundlich, Martin (University of Minnesota, Minneapolis) and Herman C. Lichstein. Tryptophanase-tryptophan synthetase systems in Escherichia coli. I. Effect of tryptophan and related compounds. J. Bacteriol. 84:979-987. 1962.-The effect of tryptophan and related compounds on tryptophanase and tryptophan synthetase formation in Escherichia coli was determined. Several of these compounds stimulated the formation of tryptophanase while concomitantly decreasing the production of synthetase. A number of tryptophan analogues were found to inhibit growth. The possible mode of action of these substances was examined further. 5-Hydroxytryptophan greatly inhibited the formation of synthetase and also reduced growth. Its inhibitory action on growth was attributed, at least partially, to the false feedback inhibition of anthranilic acid formation. Tryptamine was found to be a potent inhibitor of the activity of synthetase, as well as of the enzyme(s) involved in the synthesis of anthranilic acid from shikimic acid. However, growth reduction was only partially reversed by tryptophan. Indole-3-acetic acid and indole-3-propionic acid decreased growth and increased the formation of synthetase six- to eightfold. The action of these compounds was ascribed to their ability to block the endogenous formation of tryptophan.

Escherichia coli↗
PubMed1962

Tryptophanase-tryptophan synthetase systems in Escherichia coli. II. Effect of glucose.

Freundlich, Martin (University of Minnesota, Minneapolis) and Herman C. Lichstein. Tryptophanase-tryptophan synthetase systems in Escherichia coli. II. Effect of glucose. J. Bacteriol. 84:988-995. 1962.-The effect of glucose and other compounds on the formation of tryptophanase and tryptophan synthetase in Escherichia coli was examined. Although most of these compounds were potent inhibitors of the synthesis of tryptophanase, they invariably increased the formation of tryptophan synthetase. The severity of tryptophanase inhibition depended upon the degree of utilization of the compound by the growing bacterial cells. It was found that high levels of tryptophan overcame by 40% the repression caused by glucose. The stimulatory effect of glucose on tryptophan synthetase formation in E. coli 9723E could be duplicated by indole-3-propionic acid. A study of the amino acid pool of E. coli 9723E revealed no free tryptophan in cells harvested from the basal medium containing glucose. In contrast, cells grown in the absence of glucose possessed a measurable amount of this amino acid. The possible mechanisms of the effect of glucose and related compounds on tryptophanase and tryptophan synthetase formation, as well as the relationship of these effects to the metabolic control of tryptophan metabolism, are discussed.

Escherichia coli↗
PubMed1962

Tryptophanase-tryptophan synthetase systems in Escherichia coli. III. Requirements for enzyne synthesis.

Freundlich, Martin (University of Minnesota, Minneapolis) and Herman C. Lichstein. Tryptophanase-tryptophan synthetase systems in Escherichia coli. III. Requirements for enzyme synthesis. J. Bacteriol. 84:996-1006. 1962.-The requirements for the formation of tryptophanase and tryptophan synthetase in Escherichia coli during repression release were studied. The kinetics of the formation of tryptophan synthetase differed in the two strains examined; this was attributed to differences in the endogenous level of tryptophan in the bacterial cells. The formation of both enzymes was inhibited by chloramphenicol, and by the absence of arginine in an arginine-requiring mutant. These results are indicative of a requirement for protein synthesis for enzyme formation. Requirements for nucleic acid synthesis were examined by use of a uracil- and thymine-requiring mutant, and with purine and pyrimidine analogues. The results obtained suggest that some type of ribonucleic acid synthesis was necessary for the formation of tryptophanase and tryptophan synthetase.

Chloramphenicol↗