A quantitative metabolomics study of high sodium response in Clostridium acetobutylicum ATCC 824 acetone-butanol-ethanol (ABE) fermentation.
Hemicellulose hydrolysates, sugar-rich feedstocks used in biobutanol refinery, are normally obtained by adding sodium hydroxide in the hydrolyze process. However, the resulting high sodium concentration in the hydrolysate inhibits ABE (acetone-butanol-ethanol) fermentation, and thus limits the use of these low-cost feedstocks. We have thus studied the effect of high sodium on the metabolic behavior of Clostridium acetobutyricum ATCC 824, with xylose as the carbon source. At a threshold sodium concentration of 200 mM, a decrease of the maximum cell dry weight (-19.50 ± 0.85%) and of ABE yield (-35.14 ± 3.50% acetone, -33.37 ± 0.74% butanol, -22.95 ± 1.81% ethanol) were observed compared to control culture. However, solvents specific productivities were not affected by supplementing sodium. The main effects of high sodium on cell metabolism were observed in acidogenesis, during which we observed the accumulation of ATP and NADH, and the inhibition of the pentose phosphate (PPP) and the glycolytic pathways with up to 80.73 ± 1.47% and 68.84 ± 3.42% decrease of the associated metabolic intermediates, respectively. However, the NADP(+)-to-NADPH ratio was constant for the whole culture duration, a phenomenon explaining the robustness of solvents specific productivities. Therefore, high sodium, which inhibited biomass growth through coordinated metabolic effects, interestingly triggered cell robustness on solvents specific productivity.
Research Laboratory in Applied Metabolic Engineering, Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Centre-ville Station, Montreal, Quebec, H3C 3A7, Canada.
Xinhe
X
Zhao
Research Laboratory in Applied Metabolic Engineering, Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Centre-ville Station, Montreal, Quebec, H3C 3A7, Canada.
Stefan
S
Condruz
Research Laboratory in Applied Metabolic Engineering, Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Centre-ville Station, Montreal, Quebec, H3C 3A7, Canada.
Jingkui
J
Chen
Research Laboratory in Applied Metabolic Engineering, Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Centre-ville Station, Montreal, Quebec, H3C 3A7, Canada.
Mario
M
Jolicoeur
D000096:Acetone / Q000378:metabolism*; D000440:Butanols / Q000378:metabolism*; D046969:Clostridium acetobutylicum / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D055442:Metabolome / Q000187:drug effects*; D055432:Metabolomics; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology*
D000440:Butanols; D000096:Acetone; D000431:Ethanol; D012964:Sodium