Identification and functional expression of a new xylose isomerase from the goat rumen microbiome in Saccharomyces cerevisiae

Abstract

Significance and Impact of the Study: Heterologous expression of bacterial xylose isomerases rarely allows Saccharomyces cerevisiae to grow on xylose as sole carbon source. Functional metagenomics led to the identification of a new xylose isomerase from the goat rumen microbiome. The gene GR-XI 1 originated from a phylum Firmicutes bacterium, and it was successfully expressed in S. cerevisiae, after codon optimization and renaming to XySC1. Expression of XySC1 allowed the yeast to grow and ferment xylose as sole carbon source. This work is an example of how functional metagenomics is a powerful approach to identify new genes that can have application in the second-generation bioethanol industry.