Figure 1.

S. oneidensis possesses both anaerobic and aerobic UFA biosynthesis pathways. (A) Genetic organization of desA_So (SO0197) and comparison of the fatty acyl desaturase conserved histidine clusters, characteristic of desaturases. S. cerevisiae acyl-CoA desaturase (Ole1p) and DesA_So are aligned. Identical amino acids are highlighted in dark blue and similar amino acids are highlighted in light blue. (B) Growth of ΔfabA_So, ΔdesA_So, and ΔfabA_So ΔdesA_So strains in liquid media under aerobic and anaerobic conditions. Genetic complementation results are given in Figure S1. (C) Growth of ΔfabA_So, ΔdesA_So, and ΔfabA_SoΔdesA_So strains on solid media. Cultures of the mid-log phase for each strain were properly diluted, placed on LB plates, incubated for 24 and 48 h under aerobic and anaerobic conditions, respectively. ΔfabA_So was complemented by chemically (supplement of oleate) or genetically (expression of fabA_So in trans). (D) Colony color phenotype of mutants defective in UFA synthesis. In order to support growth of ΔfabA_SoΔdesA_So, oleate was supplemented when necessary. The double mutant was complemented by desA_Pa, fabA_So, or desA_So in trans, with empty vector (Vec) as control. ΔfabA_So and ΔdesA_So strains were indistinguishable from WT (not shown). In (B–D) experiments were conducted independently at least three times and similar results were obtained (C,D) or standard deviations (less than 5% of the means) were omitted for clarity (B).