Increase of the yields of eicosapentaenoic and docosahexaenoic acids by the microalga Pavlova lutheri following random mutagenesis.

Abstract

The high commercial values of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids have driven a strain-improvement program, aimed at increasing the content of those fatty acids in the microalga Pavlova lutheri (SMBA 60) as parent strain. After a round of mutation using UV-light as mutagenic agent, an isolate strain (tentatively called II#2) was obtained, the EPA and DHA contents of which (in % dry biomass) were 32.8% and 32.9% higher than those of the control, native strain. The final EPA yields, when the cultures were maintained under appropriate conditions, were 17.4 and 23.1 mg. g(-1) dry biomass, for the wild-type and the II#2 strain, respectively, whereas the final DHA yields were 8.0 and 10.6 mg. g(-1) dry biomass, respectively. These results suggest that random mutagenesis can successfully be applied to increase the yield of n-3 fatty acids by microalgae.