Studies on cyclopropane fatty acid synthesis. Correlation between the state of reduction of respiratory components and the accumulation of methylene hexadecanoic acid by Pseudomonas denitrificans.
A delay in the onset of accumulation of methylene hexadecanoic acid could be engendered in Pseudomonas denitrificans growing under limited oxygen conditions when the concentration of citrate but not the concentration of succinate in the medium was increased from 0.1 to 0.5%. Ascorbate, which specifically reduced a cytochrome component possessing a maximum absorbance at 551 nm, partially inhibited the accumulation of methylene hexadecanoic acid under conditions which otherwise led to maximal production. Limiting terminal cytochrome oxidase activity by controlling the oxygen supply, or by the use of low concentrations of the oxidase inhibitors cyanide or azide also prevented the accumulation of the fatty acid regardless of the nature or concentration of carbon source in the medium. Measurement of the levels of ATP, NAD and NADH as well as the steady state of reduction of respiratory components in vivo showed that the onset of accumulation of methylene hexadecanoic acid could be specifically correlated with the state of reduction of respiratory components. The uniqueness of succinate respiration in promoting the synthesis of cyclopropane synthetase (unsaturated-phospholipid methyltransferase (EC 2.1.1.16) under limited oxygen conditions could therefore be assigned to the high degree of oxidation of respiratory components observed under this condition.
D001205:Ascorbic Acid / Q000494:pharmacology; D003521:Cyclopropanes / Q000096:biosynthesis*; D005227:Fatty Acids / Q000096:biosynthesis*; D006873:Hydroquinones / Q000494:pharmacology; D008715:Methionine / Q000494:pharmacology; D008780:Methyltransferases / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011549:Pseudomonas / Q000187:drug effects / Q000378:metabolism*
D003521:Cyclopropanes; D005227:Fatty Acids; D006873:Hydroquinones; C028775:cyclopropane fatty acids; D009243:NAD; C028528:methylene hexadecanoic acid; D008715:Methionine; D008780:Methyltransferases; C019964:cyclopropane synthetase; D001205:Ascorbic Acid; C031927:hydroquinone