Environmentally-induced changes in the Fatty acids of chlorella.

Qualitative and quantitative analyses were made of the major fatty acids of Chlorella fusca, Shihira and Krauss, in both autotrophic and heterotrophic culture. Cells grown heterotrophically were subjected to CO(2) concentrations as great as 40%-in-air.The major fatty acids of autotrophic cells grown under a 1% environmental concentration of CO(2), in order of concentration were 16:0, 18:3, 16:4, 18:2, 18:1, and 16:3. The analysis of heterotrophic cells at 1% CO(2), by comparison, indicated a complete absence of 16:4, reduced amounts of 18:3, and increased amounts of the other major acids.An increase in the environmental concentration of CO(2) (from 1%-30%) over the heterotrophic cultures produced a 40% increase in total lipids and nearly a 50% increase in fatty acids. Palmitic acid (16:0) and 18:1 largely account for the fatty acid change by increasing from 12 mg to 33 mg/g dry wt and 8 mg to 17 mg/g dry wt respectively. Possible explanations for this enhanced synthesis of fatty acids are suggested.