The role of peroxisomes in xylose alcoholic fermentation in the engineered Saccharomyces cerevisiae.

Xylose is a second-most abounded sugar after glucose in lignocellulosic hydrolysates and should be efficiently fermented for economically viable second-generation ethanol production. Despite significant progress in metabolic and evolutionary engineering, xylose fermentation rate of recombinant Saccharomyces cerevisiae remains lower than that for glucose. Our recent study demonstrated that peroxisome-deficient cells of yeast Ogataea polymorpha showed a decrease in ethanol production from xylose. In this work, we have studied the role of peroxisomes in xylose alcoholic fermentation in the engineered xylose-utilizing strain of S. cerevisiae. It was shown that peroxisome-less pex3Δ mutant possessed 1.5-fold decrease of ethanol production from xylose. We hypothesized that peroxisomal catalase Cta1 may have importance for hydrogen peroxide, the important component of reactive oxygen species, detoxification during xylose alcoholic fermentation. It was clearly shown that CTA1 deletion impaired ethanol production from xylose. It was found that enhancing the peroxisome population by modulation the peroxisomal biogenesis by overexpression of PEX34 activates xylose alcoholic fermentation.