Selection of oleaginous yeasts with high lipid productivity for practical biodiesel production

• The lipid-producing ability of 500 newly isolated yeast strains was evaluated.
• Lipid content, fatty acid composition, lipid productivity, and biomass were examined.
• The yeast Cryptococcus musci was capable of the highest lipid productivity.

The lipid-accumulating ability of 500 yeast strains isolated in Japan was evaluated. Primary screening revealed that 31 strains were identified as potential lipid producers, from which 12 strains were cultivated in a medium containing 3% glucose. It was found that JCM 24511 accumulated the highest lipid content, up to 61.53%, while JCM 24512 grew the fastest. They were tentatively identified as Cryptococcus sp. and Cryptococcus musci, respectively. The maximum lipid concentration of 1.49 g/L was achieved by JCM 24512. Similarly, JCM 24511 also achieved a high lipid production of 1.37 g/L. High lipid productivity is the most important characteristic of oleaginous yeasts from the viewpoint of practical production. Among the strains tested here, JCM 24512 had the best lipid productivity, 0.37 g/L/day. The results show that the isolated yeasts could be promising candidates for biodiesel production.