Adaptive laboratory evolution of Rhodosporidium toruloides to inhibitors derived from lignocellulosic biomass and genetic variations behind evolution

• Published in: Bioresource technology Vol. 333; p. 125171
• Main Authors: Liu, Zhijia, Radi, Mohammad, Mohamed, Elsayed T.T., Feist, Adam M., Dragone, Giuliano, Mussatto, Solange I.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2021
• Subjects: Adaptive laboratory evolution; Hydrolysate; Inhibitors; Rhodosporidium toruloides; Tolerance; Tolerance; Inhibitors; Hydrolysate; Adaptive laboratory evolution; Rhodosporidium toruloides
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.125171

•A strategy of adaptive laboratory evolution in hydrolysate-based medium was developed.•Evolved strains of Rhodosporidium toruloides presented better tolerance to inhibitors.•The strain’s ability to accumulate lipids and produce carotenoids was also improved.•Whole genome sequencing revealed tolerance-related genes in the wild-type strain. Using lignocellulosic biomass hydrolysate for the production of microbial lipids and carotenoids is still a challenge due to the poor tolerance of oleaginous yeasts to the inhibitors generated during biomass pretreatment. In this study, a strategy of adaptive laboratory evolution in hydrolysate-based medium was developed to improve the tolerance of Rhodosporidium toruloides to inhibitors present in biomass hydrolysate. The evolved strains presented better performance to grow in hydrolysate medium, with a significant reduction in their lag phases, and improved ability to accumulate lipids and produce carotenoids when compared to the wild-type starting strain. In the best cases, the lag phase was reduced by 72 h and resulted in lipid accumulation of 27.89 ± 0.80% (dry cell weight) and carotenoid production of 14.09 ± 0.12 mg/g (dry cell weight). Whole genome sequencing analysis indicated that the wild-type strain naturally contained tolerance-related genes, which provided a background that allowed the strain to evolve in biomass-derived inhibitors.