All You Can Eat Yeast: Substituting Hexose Transporters With AtSWEET7 Alleviates Glucose Repression, Enabling...

Yeast sugar transporters have highly evolved for preferential glucose transport, a significant roadblock for utilizing non-glucose sugars in renewable feedstocks such as lignocellulosic biomass. To enable simultaneous transport of multiple sugars, native hexose transporters were replaced by SWEET7p from Arabidopsis thaliana in engineered Saccharomyces cerevisiae capable of fermenting xylose. Engineered S. cerevisiae exhibited reduced glucose preference, simultaneously co-fermenting glucose, mannose, fructose, and xylose both in synthetic and industrial media. Continuous culture experiments demonstrated the co-consuming phenotype and alleviation of glucose repression by engineered S. cerevisiae. In addition to hexose and pentose, the NKSW7-1 strain consumed xylitol as a carbon source. Through transcriptomic and metabolomic analysis of the NKSW7-1 strain, we show that the replacement of HXT1-7 with AtSWEET7 led to systemwide reprogramming of the central carbon metabolism. This broad transport capacity of AtSWEET7p holds promise for achieving co-consumption of all sugars in underutilized renewable feedstocks by microbial cell factory.