Engineering Chromatin Regulation of Xylose Utilization in Budding Yeast Saccharomyces cerevisiae for Efficient Bioconversion

Utilization of xylose as a renewable carbon source has received constant interest. Considering that the structure and state of eukaryotic chromatin are inextricably intertwined, it is significant to explore chromatin regulation for engineering xylose metabolism in yeast. Here, we show that two chromatin remodelers, namely, Swr1 and Isw1, affect xylose utilization in recombinant budding yeastSaccharomyces cerevisiae. Overexpressing SWR1 showed the highest increase in xylose utilization, up to 29.3%, compared to that of the parent strain. Furthermore, comparative transcriptome and chromatin immunoprecipitation sequencing (ChIP-seq) analyses revealed significantly different changes of gene expression by elevated expression of Swr1 and Isw1. Reduced histone H2A.Z occupancy in two key carbon-metabolism regulators of Mig2 and Sip2 was further observed in the engineered yeast. Further tests showed improved xylose utilization of the engineered yeast in the presence of corncob hydrolysate. Our results suggest that chromatin regulators are critical genetic elements in recombinant S. cerevisiae for engineering xylose metabolism.