SYNTHESIS OF TRANS UNSATURATED FATTY-ACIDS IN PSEUDOMONAS-PUTIDA P8 BY DIRECT ISOMERIZATION OF THE DOUBLE-BOND OF LIPIDS

The phospholipids of Pseudomonas putida P8 contain monounsaturated fat ty acids in the cis and trans configuration. Cells of this phenol-degr ading bacterium change the proportions of these isomers in response to the addition or elimination of a membrane active compound such as 4-c hlorophenol. This study undoubtedly reveals that the cis unsaturated f atty acids are directly converted into trans isomers without involveme nt of de novo synthesis of fatty acids. Oleic acid, which cannot be sy nthesized by this bacterium, was incorporated as a cis unsaturated fat ty acid marker in the membrane lipids of growing cells. The conversion of this fatty acid into the corresponding trans isomer was demonstrat ed by gas chromatographic-mass spectrometric analysis and use of C-14- labeled oleic acid. Separation and isolation of the cellular membranes showed that the fatty acid isomerase is located in the cytoplasmic me mbrane of P. putida P8.