Native and synthetic methanol assimilation in Saccharomyces cerevisiae

Microbial fermentation for chemical production is becoming more broadly adopted as an alternative to petrochemical refining. Fermentation typically relies on sugar as a feed-stock. However, one-carbon compounds like methanol are a more sustainable alternative as they do not compete with arable land. This study focused on engineering the capacity for methylotrophy in the yeast Saccharomyces cerevisiae through a yeast xylulose monophosphate (XuMP) pathway, a ‘hybrid’ XuMP pathway, and a bacterial ribulose monophosphate (RuMP) pathway. Through methanol toxicity assays and 13C-methanol-growth phenotypic characterization, the bacterial RuMP pathway was identified as the most promising synthetic pathway for methanol assimilation. When testing higher methanol concentrations, methanol assimilation was also observed in the wild-type strain, as 13C-ethanol was produced from 13C-methanol. These results demonstrate that S. cerevisiae has a previously undiscovered native capacity for methanol assimilation and pave the way for further development of both native and synthetic one-carbon assimilation pathways in S. cerevisiae.