Argentation thin-layer chromatographic analysis of [1-14C] acetate-labeled esters from strain CY57 transformed with pHW22 encoding C. acetobutylicium fabZ. The methyl esters of fatty acids were obtained from the phospholipids as described in Methods. Lane 1 is the methyl esters of the wild type E. coli strainMG1655. Lane 2 is the esters of strain CY57 carrying vector pBAD24. Lane 3 is the esters of strain CY57 carrying pHW22 which encodes the C. acetobutylicium fabZ labeled in the absence of induction. Lane 4 is the esters of strain CY57 (pHW22) following arabinose induction. Labels are as in Fig. 2.