Mechanistic modeling of redox balance effects on the fermentation of eucalyptus wood-derived xylose to acetone-butanol-ethanol

Autor(es)

Rivera, Elmer C. ; Assumpcao, Daniel C. ; Kwon, Hyun J. ; Okonkwo, Christopher C. ; Ezeji, Thaddeus C. ; Filho, Rubens M. ; Mariano, Adriano P.

• Tipo de documento: Artigo Científico
• Fonte: Biochemical Engineering Journal; v. 190, p. 12-pg., 2023-01-01.

Resumo

A Michaelis-Menten-like kinetic model is proposed to simulate the effects of redox balance on Clostridium beijerinckii NCIMB 8052 metabolism during fermentation of biomass-derived xylose to acetone-butanol-ethanol (ABE). The model builds on previous metabolic kinetic models by introducing six mass balance differential equations for the redox pairs NADH/NAD+, NADPH/NADP+, and oxidized/reduced ferredoxin. Batch cultures were conducted using laboratory-grade or eucalyptus-derived xylose, and kinetic parameters were estimated by minimizing the difference between experimental (substrate, metabolites, and cell) and model results using a genetic optimization algorithm. The simulations agreed well with experimental data, and a sensitivity analysis showed that the rate of reoxidation of reduced ferredoxin used for NADPH regeneration is the most relevant reaction for the synthesis of acids and ABE. Furthermore, an increase in NADPH consumption due to the reduction of eucalyptus-derived furfural to furfuryl alcohol was only significant for the production of butanol. Differences in the values of the Michaelis-Menten constants, Km's, depending on the xylose source, suggest that a decrease in the conversion rates of lactate to pyruvate and acetate to acetyl-CoA considerably affected the biosynthesis of butanol from eucalyptus-derived xylose. The proposed model was effective in assessing the effects of redox balance on ABE fermentation, suggesting its use for the design of metabolic engineering strategies to improve butanol synthesis from furfural-containing biomass hydrolysates. (AU)

• Processo FAPESP: 15/07097-5 - Desenvolvimento de um bioprocesso com alta eficiência energética para a produção flexível de butanol/etanol integrado a uma usina kraft de celulose
• Beneficiário: Adriano Pinto Mariano
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Regular
• Processo FAPESP: 16/01785-0 - Produção de butanol a partir de madeira de eucalipto: efeito do glicerol na desintoxicação in situ de inibidores microbianos derivados de material lignocelulósico e análise in silico do metabolismo do Clostridium beijerinckii NCIMB 8052
• Beneficiário: Elmer Alberto Ccopa Rivera
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• Processo FAPESP: 15/50243-2 - Energy-efficient production of butanol (an advanced biofuel) from eucalyptus wood
• Beneficiário: Adriano Pinto Mariano
• Modalidade de apoio: Auxílio à Pesquisa - Regular