Rescuing yeast from cell death enables overproduction of fatty acids from sole methanol

Methanol is an ideal feedstock for biomanufacturing that can be beneficial for global carbon neutrality; however, the toxicity of methanol limits the efficiency of methanol metabolism toward biochemical production. We here show that engineering production of free fatty acids from sole methanol results in cell death with decreased cellular levels of phospholipids in the methylotrophic yeast Ogataea polymorpha, and cell growth is restored by adaptive laboratory evolution. Whole-genome sequencing of the adapted strains reveals that inactivation of LPL1 (encoding a putative lipase) and IZH3 (encoding a membrane protein related to zinc metabolism) preserve cell survival by restoring phospholipid metabolism. Engineering the pentose phosphate pathway and gluconeogenesis enables high-level production of free fatty acid (15.9 g l-1) from sole methanol. Preventing methanol-associated toxicity underscores the link between lipid metabolism and methanol tolerance, which should contribute to enhancing methanol-based biomanufacturing.