Modeling of batch fermentation kinetics for succinic acid production by Mannheimia succiniciproducens

Abstract

Kinetic models are proposed for the batch production of succinic acid from glucose by Mannheimia succiniciproducens MBEL55E. The models include terms accounting for both substrate and product inhibitions. Experimental data collected from a series of batch fermentations with different initial glucose concentrations were used to estimate parameters and also to validate the models proposed. The optimal values of the parameters were approximated by minimizing the discrepancy between the model predictions and corresponding experimental data. The growth of M. succiniciproducens could be expressed by a modified Monod model incorporating inhibitions of glucose and organic acids accumulated in the culture broth. The Luedeking–Piret model was able to describe the formation of organic acids as the fermentation proceeded, in which succinic, acetic, and formic acids followed a mixed-growth-associated pattern. However, unexpectedly, lactic acid fermentation by M. succiniciproducens was nearly nongrowth-associated. In all cases, the model simulation matched well with the experimental observations, which made it possible to elucidate the fermentation characteristics of M. succiniciproducens during efficient succinic acid production from glucose. These models thus can be employed for the development and optimization of biobased succinic acid production processes.