Complete and Efficient Conversion of Plant Cell Wall Hemicellulose into High-Value Bioproducts by Engineered Yeast

Sun, L., Lee, J.W., Yook, S., Lane, S., Sun, Z., Kim, S.R., Jin, Y.S. Aug. 17, 2021. “Complete and Efficient Conversion of Plant Cell Wall Hemicellulose into High-Value Bioproducts by Engineered Yeast.” Nature Communications 12, 4975. DOI: 10.1038/s41467-021-25241-y.

Plant cell wall hydrolysates contain not only sugars but also substantial amounts of acetate, a fermentation inhibitor that hinders bioconversion of lignocellulose. Despite the toxic and non-consumable nature of acetate during glucose metabolism, we demonstrate that acetate can be rapidly co-consumed with xylose by engineered Saccharomyces cerevisiae. The co-consumption leads to a metabolic re-configuration that boosts the synthesis of acetyl-CoA derived bioproducts, including triacetic acid lactone (TAL) and vitamin A, in engineered strains. Notably, by co-feeding xylose and acetate, an engineered strain produces 23.91 g/L TAL with a productivity of 0.29 g/L/h in bioreactor fermentation. This strain also completely converts a hemicellulose hydrolysate of switchgrass into 3.55 g/L TAL. These findings establish a versatile strategy that not only transforms an inhibitor into a valuable substrate but also expands the capacity of acetyl-CoA supply in S. cerevisiae for efficient bioconversion of cellulosic biomass.

S. cerevisiae SR7 RNA-Seq PRJNA748193

BioSample accessions:

• SAMN20309334
• SAMN20309335

Download (12.4 KB) includes:

• TAL production
• Vitamin A production
• Transcriptional patterns of genes related to transport and metabolism
• Glucose and xylose utilization