Zmo0994, a novel LEA-like protein fromZymomonas mobilis, increases multi-abiotic stress tolerance inEscherichia coli

Abstract

Background Pretreatment processes and subsequent enzymatic hydrolysis are prerequisites to utilize lignocellulosic sugar for fermentation. However, the resulting hydrolysate frequently hinders fermentation processes due to the presence of inhibitors and toxic products (e.g., ethanol). Thus, it is crucial to develop robust microbes conferring multi-stress tolerance. Results Zmo0994, a functionally uncharacterized protein fromZymomonas mobilis, was identified and characterized for the first time. A major effect of Zmo0994 was a significant enhancement in the tolerance to abiotic stresses such as ethanol, furfural, 5 '-hydroxymethylfurfural and high temperature, when expressed inEscherichia coli. Through transcriptome analysis and in vivo experiments, the cellular mechanism of this protein was revealed as due to its ability to trigger genes, involved in aerobic respiration for ATP synthesis. Conclusions These findings have significant implications that might lead to the development of robust microbes for the highly efficient industrial fermentation processes.