Isolation of a thermotolerant Rhodosporidium toruloides DMKU3-TK16 mutant and its fatty acid profile at high temperature

Oleaginous yeast Rhodosporidium toruloides DMKU3-TK16 (TK16), which was isolated from Thailand, is considered a promising lipid producer for biodiesel production. For future industrial applications of this strain, thermotolerant traits are highly desired for their potential to reduce cooling costs in a commercial fermenter. Here, by using an adaptive breeding strategy, we isolated a thermotolerant R. toruloides mutant, L1-1. The isolated L1-1 strain exhibited better growth and higher lipid production at 37°C, and it was found to have significantly higher oleic acid (C18:1) content and yield compared with the wild-type TK16 when cultivated at 37°C. This is the first study to isolate a thermotolerant strain from the oleaginous yeast R. toruloides. The information gained herein will provide new clues for engineering lipid production and for studying the thermotolerance of R. toruloides.