Omega-cyclohexyl fatty acids in acidophilic thermophilic bacteria. Studies on their presence, structure, and biosynthesis using precursors labeled with stable isotopes and radioisotopes.
Omega-Cyclohexyl undecanoic acid and omega-cyclohexyl tridecanoic acid were found in 10 strains of acido-thermophilic bacteria isolated from different Japanese hot springs. These unusual fatty acids were found in the esterified form in glyceride type complex lipids and constituted 74 to 93% of the total fatty acids in the bacteria. The fatty acids other than omega-cyclohexyl fatty acids found were 14-methyl hexadecanoic acid (3 to 15%) and 15-methyl hexadecanoic acid (1 to 6%), and trace amounts of straight chain and methyl-branched tetra- and penta-decanoic acids. Biosynthesis of omega-cyclohexyl fatty acids increased with increase in the concentration of glucose in the culture medium. The metabolism of omega-cyclohexyl fatty acids was studied using deuterium-labeled precursors by mass fragmentation analysis. The deuterium of [2-D]glucose was specifically incorporated into position 2 of the cyclohexyl ring of the fatty acids, indicating that the ring was synthesized from the glucose molecule. Radioactivity was efficiently incorporated into the omega-cyclohexyl fatty acids from labeled glucose, shikimate, and cyclohexyl carboxylate. These findings indicate that omega-cyclohexyl fatty acids are synthesized with glucose through shikimic acid and probably cyclohexyl carboxylyl-CoA derivative as the intermediates.
D000085:Acetates / Q000378:metabolism; D001407:Bacillus / Q000378:metabolism*; D003509:Cyclohexanecarboxylic Acids; D003510:Cyclohexanes / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007564:Japan; D012765:Shikimic Acid / Q000378:metabolism; D013045:Species Specificity; D013329:Structure-Activity Relationship; D013696:Temperature
D000085:Acetates; D003509:Cyclohexanecarboxylic Acids; D003510:Cyclohexanes; D005227:Fatty Acids; D012765:Shikimic Acid; D005947:Glucose