Abstract
Increase in the degree of oil self-sufficiency is an important issue in Japan. Due to the decrease in agricultural population and the extent of land area in Japan, we cannot expect an increased yield of oil plant. Therefore, we noted the oleaginous yeast Lipomyces starkeyi, which can convert various saccharides such as glucose and xylose to lipid. L. starkeyi is an excellent lipid producer that is able to accumulate up to 70% of its biomass as triacylglycerols. However, there are issues of lipid productivity (lipid production rate and lipid conversion efficiency) for commercial applications. In this study, we aimed the isolation of L. starkeyi mutants accumulating a high level of lipid. L. starkeyi mutants with high accumulation of lipid were isolated following mutagenesis with Ethyl methanesulfonate. Enrichment procedures for separating high lipid accumulation cells of L. starkeyi from wild type cells were devised employing percoll density gradient centrifugation. The mutants, E15, E47, and E42, were identified in lipid accumulation using Flow cytometry and microscope analysis. Three mutants were characterized with respect to their lipid productivities.
