Gene insertions and deletions were verified by colony polymerase chain reaction (PCR) using primers 3 and 4 for fadD and 5 and 6 for araBAD, and by the absence of growth after plating on M9 agar supplemented with either 0.1% (w/v) sodium oleate (TCI America, Portland, OR) as previously described (Overath et al., 1969), or 0.4% (w/v) L-arabinose (Calbiochem,
San Diego, CA) as carbon sources (Supplementary Fig. 1).