The origin of fatty acids in the hydrocarbon-utilizing microorganism Mycobacterium vaccae.
The fatty acid pattern in Mycobacterium vaccae strain JOB5 was examined after growth on n-alkanes (C14-C18), 1-alkenes (C14-C18), 2- or 3-methyl octadecane, and 8-heptadecene. It was evident that monoterminal oxidation of n-alkanes was followed by beta-oxidation and that both parent fatty acid and products of beta-oxidation were incorporated into cellular lipids. Radioactive experiments demonstrated that there was desaturation of long-chain fatty acids. There was no evidence of chain elongation. Growth on 1-alkenes resulted in the incorporation of fatty acids that were products of two primary modes of oxidation: (1) methyl group attack resulting in omega-unsaturated fatty acids and (2) double-bond attack resulting in the removal of one carbon from the substrate. Cells of strain JOB5 grown on 2- and 3-methyl octadecane contained the corresponding iso- or anteiso-fatty acids in significant quantity. Cells cultured on 8-heptadecene contained 8- and 9-heptadecenoic acids, 6- and 7-pentadecenoic acids, 9- and 10-methyl heptadecanoic acids, and 7- and 8-methyl pentadecanoic acids. Fatty acid composition (C13 to C19) was affected by substrate chain length and was additionally modified by cellular control mechanisms.
D000085:Acetates / Q000378:metabolism; D000473:Alkanes / Q000378:metabolism*; D000475:Alkenes / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002849:Chromatography, Gas; D005227:Fatty Acids / Q000096:biosynthesis* / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis; D008055:Lipids / Q000096:biosynthesis; D009161:Mycobacterium / Q000378:metabolism*; D010084:Oxidation-Reduction
D000085:Acetates; D000473:Alkanes; D000475:Alkenes; D002250:Carbon Radioisotopes; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008055:Lipids