Introduction of Glyoxylate Bypass Increases Hydrogen Gas Yield from Acetate and l -Glutamate in Rhodobacter sphaeroides

Abstract

As an alternative to fossil fuel, H 2 is a promising renewable energy source. Although photofermentative H 2 production from acetate is key to developing an efficient process of biohydrogen production from biomass-derived sugars, H 2 yields from acetate and l -glutamate by R. sphaeroides have been reported to be low. In this study, we observed that in addition to the endogenous EMC pathway, heterologous expression of the glyoxylate bypass in R. sphaeroides markedly increased H 2 yields from acetate and l -glutamate. Therefore, this study provides a novel strategy for improving H 2 yields from acetate in the presence of l -glutamate and contributes to a clear understanding of acetate metabolism in R. sphaeroides during photofermentative H 2 production.