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G H ROTHBLAT

Publications and source records attributed to G H ROTHBLAT.

9 recordsLinked to original sources
PubMed1962

Comparison of lipid composition of pleuropneumonia-like and L-type organisms.

Smith, Paul F. (University of Pennsylvania, Philadelphia) and George H. Rothblat. Comparison of pleuropneumonia-like and L-type organisms. J. Bacteriol. 83:500-506. 1962.-The content of total lipid and nonsaponifiable lipid depended upon the type of organism; the greatest amounts were found in pleuropneumonia-like organisms that required cholesterol for growth and in L-1, the L-form of Streptobacillus moniliformis. Decreasing amounts were found in nonsterol-requiring strains of pleuropneumonia-like organisms, the stable L-form of Proteus, salt-requiring L-forms, and finally, the bacterial parents of the L-type organisms. Nonsterol-requiring pleuropneumonia-like organisms could synthesize their own nonsaponifiable lipid, but sterol-requiring strains could not. Ability or inability to synthesize nonsaponifiable lipid was often carried over to the L-type organisms from the bacterial parent. More nonsaponifiable lipid was found in the sedimentable fraction (cell membrane) than in the nonsedimentable fraction (protoplasm) of both pleuropneumonia-like and L-type organisms. None of the nonsaponifiable lipid synthesized by any organism tested appeared to be 3-beta-hydroxy sterol. Differences in ability of various organisms to take up cholesterol and to be lysed by digitonin were established.

Cell Membrane↗
PubMed1961

Nonsaponifiable lipids of representative pleuropneumonia-like organisms.

Rothblat, George H. (University of Pennsylvania, Philadelphia), and Paul F. Smith. Nonsaponifiable lipids of representative pleuropneumonia-like organisms. J. Bacteriol. 82:479-491. 1961.-The fate of cholesterol and the nature of carotenoid pigments in various strains of pleuropneumonia-like organisms have been determined by characterization of their nonsaponifiable lipids. All of the cholesterol removed from the medium by a nonfermentative sterol-requiring strain remains unchanged except for a portion of it being esterified. A fermentative sterol-requiring strain of avian origin converts part of the cholesterol to cholesteryl-beta-d-glucoside, the amount in the glucoside form being governed by the amount of glucose supplied in the growth medium. This cholesteryl-beta-d-glucoside was found to be formed by a fermentative, nonsterol-requiring strain only when supplied exogenous cholesterol. No cholesterol or its derivatives were found in nonsterol-requiring strains when grown in the absence of cholesterol. Three carotenoid pigments were isolated from nonsterol-requiring strains. The most nonpolar pigment was identified as neurosporene. The second pigment appearing in chromatographic column eluates appears to be a hydroxylated neurosporene, based on its polarity and absorption spectrum. The most polar pigment was found to contain reducing sugar following acid hydrolysis and appears to be a carotenoid-glucose complex. When the nonsterol-requiring strains are grown in the presence of cholesterol, cholesterol partially supplants the role of carotenoids and decreases the amount of carotenoids synthesized. The role of steroids and carotenoids in these organisms is discussed.

Carotenoids↗