Rice straw-derived lipid production by HMF/furfural-tolerant oleaginous yeast generated by adaptive laboratory evolution.

Research on producing medium- and long-chain hydrocarbons as drop-in biofuels has recently accelerated. In addition, lipids are emerging as precursors for biofuel production, and thus, microbial lipid production utilizing agrowastes is becoming a feasible platform technology. Nonetheless, microorganisms are often inhibited by furan aldehydes in biomass-derived hydrolysates. Accordingly, this study aimed to develop oleaginous yeast strains that can tolerate furan aldehydes for producing lipids as biofuel precursors. Rhodosporidium toruloides was selected as the target for adaptive laboratory evolution. The evolved strain, which was obtained from 16 rounds of subcultures, showed a 2.5-fold higher specific growth rate than the wild-type strain in the presence of furan aldehydes and slightly higher lipid production in rice straw hydrolysate. The results discussed in this study provide insights into the production of lipid production by oleaginous yeast utilizing agrowastes as feedstock to obtain drop-in biofuels and contribute to feasible strategies to address climate crises.