Effect of inoculum size on the inhibition of organic acids. Each organic acid was tested at the molar concentration of the tested organic acids that caused 50% inhibition of the lipid yield of Trichosporon fermentans. Cultures were incubated initially at pH 6.5, 25°C and 160 rpm for 7 days. The results are expressed relative to controls without organic acids. Biomass, lipid content and lipid yield of cultures in the absence of organic acids with 5%, 10% and 15% inoculum sizes were, respectively, 24.0 g/L, 61.7% and 14.8 g/L; 22.4 g/L, 58.6% and 13.1 g/L; and 21.6 g/L, 54.3% and 11.7 g/L. Ac, acetic acid; Fo, formic acid; Le, levulinic acid; Hy, 4-hydroxybenzoic acid; Fu, furoic acid; Ca, caproic acid; Ga, gallic acid; Fe, ferulic acid; Sy, syringic acid; Va, vanillic acid.