NADH-based kinetic model for acetone-butanol-ethanol production by Clostridium

Juan Carlos Quintero-Díaz; Diego F Mendoza; Claudio Avignone-Rossa

doi:10.3389/fbioe.2023.1294355

NADH-based kinetic model for acetone-butanol-ethanol production by Clostridium

Front Bioeng Biotechnol. 2023 Nov 24:11:1294355. doi: 10.3389/fbioe.2023.1294355. eCollection 2023.

Authors

Juan Carlos Quintero-Díaz¹, Diego F Mendoza¹, Claudio Avignone-Rossa²

Affiliations

¹ Department of Chemical Engineering, Universidad de Antioquia, Medellín, Colombia.
² Department of Microbial Sciences, School of Biosciences, University of Surrey, Guildford, United Kingdom.

Abstract

We present in this work a kinetic model of the acetone-butanol-ethanol (ABE) fermentation based on enzyme kinetics expressions. The model includes the effect of the co-substrate NADH as a modulating factor of cellular metabolism. The simulations obtained with the model showed an adequate fit to the experimental data reported by several authors, matching or improving the results observed with previous models. In addition, this model does not require artificial mathematical strategies such as on-off functions to achieve a satisfactory fit of the ABE fermentation dynamics. The parametric sensitivity allowed to identify the direct glucose → acetyl-CoA → butyryl-CoA pathway as being more significant for butanol production than the acid re-assimilation pathway. Likewise, model simulations showed that the increase in NADH, due to glucose concentration, favors butanol production and selectivity, finding a maximum selectivity of 3.6, at NADH concentrations above 55 mM and glucose concentration of 126 mM. The introduction of NADH in the model would allow its use for the analysis of electrofermentation processes with Clostridium, since the model establishes a basis for representing changes in the intracellular redox potential from extracellular variables.

Keywords: ABE fermentation; electrofermentation; mathematical structured modeling; parametric sensitivity; redox mediator.

Grants and funding

The authors declare financial support was received for the research, authorship, and/or publication of this article. Ministerio de Ciencia, Tecnología e Innovación of Colombia, by research contract No. 80740-177.2019. CA-R was partially supported by the C1-NET BBSRC Proof of Concept Grant POC-22-rossa-C1net.