(2-Chloroethyl)trimethylammonium chloride (CCC), (2-hydroxyethyl)trimethylammonium chloride (CC), and (2-hydroxyethyl)trimethylammonium chloride phosphate (PCC) were studied relative to their effects on the growth and lipid composition of Chlorella vulgaris grown in continuous culture. Each chemical was added to a culture in the following sequence of concentrations: 10−6, 10−5, and 10−4 M. CC was the most effective inhibitor of cell growth and caused sequential growth reductions at increasing concentrations. CCC and PCC at 10−6 M initially inhibited cell growth, but growth recovery occurred with subsequent addition of higher concentrations of these chemicals. The polar lipid fatty acid (PL-FA), free fatty acid (FFA), triacylglycerol fatty acid (TAG-FA), and paraffinic hydrocarbon (PH) composition was determined for cells treated with each chemical. CCC at 10−5 and 10−4 M caused significant increases in TAG-FA. CC at 10−4 M stimulated TAG-FA, FFA, and PH production but inhibited PL-FA levels. PCC at 10−6 M significantly inhibited PL-FA concentrations but was stimulatory at 10−4 M. The reverse was true for the FFA concentrations relative to PCC treatments. Qualitative changes were also observed in the unsaturated fatty acid composition of the PL-FA and FFA lipid classes.
