PubMed Health⌕ Search

Biomedical subjects

P MACLEOD

Publications and source records attributed to P MACLEOD.

10 recordsLinked to original sources
PubMed1963

FATTY ACID COMPOSITION OF LIPIDS FROM STREPTOCOCCUS CREMORIS AND STREPTOCOCCUS LACTIS VAR. MALTIGENES.

MacLeod, Patricia (University of Connecticut, Storrs) and Joseph P. Brown. Fatty acid composition of lipids from Streptococcus cremoris and Streptococcus lactis var. maltigenes. J. Bacteriol. 85:1056-1060. 1963.-A method for the extraction of lipids from bacterial cells, involving grinding in a ball mill, is described. Cells of Streptococcus lactis var. maltigenes and S. cremoris yielded 5.3 and 5.5%, respectively, of their dry cellular weights as lipid. The lipids of both organisms were separated into three fractions by thin-layer chromatography. Two of these fractions have been classified: one fraction containing phospho- and perhaps glycolipids and the other containing triglycerides. The unidentified fraction was probably either mono- or diglyceride in nature. The fatty acid composition of the total lipid as well as that of each of the separated lipid components from the two lactic strains were compared.

Chemical Phenomena↗
PubMed1962

Quantity and fatty acid composition of lipid extracted from cells of Streptococcus lactis.

MacLeod, Patricia (University of Connecticut, Storrs), R. G. Jensen, G. W. Gander, and J. Sampugna. Quantity and fatty acid composition of lipid extracted from cells of Streptococcus lactis. J. Bacteriol. 83:806-810. 1962.-A method for the extraction of lipid from bacterial cells is described. Lysozyme-treated cells of Streptococcus lactis yielded 5% of their dry weight as lipid, whereas cells not treated with lysozyme yielded only 3% lipid. More than two-thirds of the bacterial lipid extracted was tentatively classified as phospholipid, based on the elution behavior of this fraction on silicic acid columns when chloroform and methanol were the eluting solvents. The following five major fatty acids were present in all lipid fractions isolated: myristic, palmitic, palmitoleic, lactobacillic, and an 18-carbon acid possessing one double bond, which may actually be oleic acid or a mixture of oleic and one or more of its isomers. These acids comprised more than 85% of the acids found, as indicated by gas-liquid chromatography of their methyl esters. Since lactobacillic acid accounted for about 20% of the fatty acids extracted from cells of S. lactis, this organism may prove to be a ready source of this comparatively rare acid.

Chromatography, Gas↗
PubMed1959

Alpha-keto acids in vitamin-free casein hydrolyzates (acid).

alpha-Ketoglutaric and pyruvic acids were isolated as their 2-4-dinitrophenylhydrazones from five different commercial samples of vitamin-free acid hydrolyzates of casein. In addition, one sample yielded traces of alpha-ketobutyric acid. The hydrazones were converted by hydrogenation to glutamic acid, alanine, and alpha-aminobutyric acid and identified by paper chromatography.

Alanine↗