Fig. 4.
Comparison of hydrocarbon extracts from wild type (WT), ols deletion mutant (Δols), and Φ(PpsbA-ols) strains of PCC 7002 supplemented with pentadecanoic (C15:0) acid. The GC-MS signal was normalized to the height of an internal standard peak (hexadecane, 8.3 min). Supplementation of cultures with heptadecanoic (C17:0) resulted in similar traces (not shown). Supplementation of odd chain fatty acids resulted in increased production of 1-octadecene (C18:1) and a compound consistent with a doubly unsaturated 18-carbon hydrocarbon (C18:2). No peaks corresponding to a 1-hexadecene analytical standard were observed in any of the extracts.