Total fatty acid content of S. obliquus wild type and five selected starch mutants. Values presented as percentage of dry weight. The dotted line and the solid line represent nitrogen-replete and nitrogen-depleted conditions, respectively. The greyscale lines in the plots represent the wild type TFA content. The values are derived from duplicate cultures. Deviation from the duplicate average is indicated by the error bars. slm, starchless mutant; TFA, total fatty acid; wt, wild type.