Fig. 6
Accumulation of free fatty acids in different E. coli strains. In vivo labeling of E. coli using [14C]acetate and after thin-layer chromatographic separation of lipids was performed. The accumulation of free fatty acids of the different ΔfadD E. coli JM101, PB11, PB12 and PB13 derivative strains at 24, 48 and 72 h of growth were determined. The experiments were made by triplicate. In all strains lacking the fadD gene, a progressive increase of free fatty acid was observed over time due to a lack of consumption. The PB11ΔfadD and PB13ΔfadD strains reached 18 and 33 % of the total lipidic species after 72 h. Interestingly, the PB12ΔfadD reached around 8 % of free fatty acids while the JM101ΔfadD reached about 12 % in 72 h of growth. The control strains are capable to consume completely the generated free fatty acids during the growth