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

Abstract

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.

Augmented peroxisomal ROS buffering capacity renders oxidative and thermal stress cross-tolerance in yeast

“…We identified organelles according to Aksam et al [ 32 ]. In theory, the larger the peroxisome, the more peroxisomal enzymes are contained [ 33 ]. More peroxisomal enzymes were hypothesized to be embedded in the peroxisomes of G14 than the parent.…”

“…The antioxidant defence system scavenges the ROS generated in yeast cells and requires the presence of antioxidants such as superoxide dismutase, catalase, thioredoxins, peroxiredoxin, and glutathione [ 16 , 41 – 44 ]. Peroxisomes are responsible for cellular ROS generation and detoxification [ 33 , 45 ]. Catalase, known as a ROS scavenger, is mostly localized in peroxisomes [ 46 ].…”

“…Catalase, known as a ROS scavenger, is mostly localized in peroxisomes [ 46 ]. In xylose alcoholic fermentation, the active fission of peroxisomes and an increase of peroxisomes size enhances the efficient ROS detoxification [ 33 ]. Overexpression of peroxisomal biogenesis gene PEX34 improves xylose alcoholic fermentation efficiency [ 33 ].…”

“…In xylose alcoholic fermentation, the active fission of peroxisomes and an increase of peroxisomes size enhances the efficient ROS detoxification [ 33 ]. Overexpression of peroxisomal biogenesis gene PEX34 improves xylose alcoholic fermentation efficiency [ 33 ]. Consistent with these results, the peroxisomes size in G14 was larger than that in the parent (Fig.…”

Xylose Assimilation for the Efficient Production of Biofuels and Chemicals by Engineered Saccharomyces cerevisiae

“…Subsequent evolutionary engineering studies guided by multi‐omics techniques generated numerous genetic targets for improved xylose fermentation in addition to creating a deeper understanding of yeast xylose metabolism at a systems‐level. These studies highlight the need for widespread cellular remodeling in regulatory, [ 79 ] signaling, [ 45 ] and structural systems [ 95 ] rather than pathway‐level optimization. Thus, advanced metabolic engineering approaches such as TF, [ 96 ] regulon, [ 40 ] and organelle [ 95 ] engineering may ultimately be necessary to maximize the xylose fermentation capacity of yeast.…”