Selection of Yeast High in Lipids-yield by Fatty Acid Synthetase Inhibitor and Phosphoric Acid-vanillin Reaction

Abstract:

Rhodotorula glutinis (Fresenius) Harrison was irradiated with 80 MeV/u carbon ions. primary selection of yeast high in lipids-yield was performed with culture medium supplemented cerulenin, an inhibitor of fatty acid synthetase (FAS). The quantity of the lipids of selected strains was analyzed by phosphoric acid-vanillin reaction and traditional methanol-chloroform extraction methods. The results showed that the growth of Rhodotorula glutinis (Fresenius) could be inhibited efficiently by cerulenin. The inhibition rate was up to 98% at cerulenin concentration of 8.96×10-6 mol/L, which was considered suitable for mutant selection. Through the phosphoric acid-vanillin reaction, it was found that the quantity of the lipids was a positive linear relation with the OD at 530 nm. The positive mutant rate of primary selection reached to 65%. With the advantage of rapid and easy to perform, it can be considered as a good method to select yeast high in lipid-yield. By these methods, 2 mutant strains with lipid yield improved 90% compared with control was selected out.

Key words:Microbial lipids, Fatty acid synthetase (FAS), Cerulenin, Phosphoric acid-vanillin reaction