Kinetics of the Bioproduction of Succinic Acid by Actinobacillus succinogenes from Oil Palm Lignocellulosic Hydrolysate in a Bioreactor

Abstract

Soluble products from oil palm frond hydrolysate (OPFH) were incorporated as the fermentation substrate for succinic acid (SA) production. To construct a reliable kinetic model for the production of SA from OPFH, the inhibitory effects during fermentation involving glucose were evaluated based on the modified Gompertz model. The application of the modified Gompertz model was found to fit well with the experimental data for characterizing the SA fermentation profile and could predict the maximum potential of the metabolite formation in the form of concentrations, production rates, and initial lag times. The maximum potential of the SA production was determined to be 38.0 g/L, which was yielded from 61.3 g/L glucose in anaerobic batch cultivation after 30 h. The inhibitory effects on the cell growth and SA production became more apparent at higher substrate concentrations, which coincided with the substrate inhibition constant of 78.7 g/L. The model also helped in estimating the OPFH fermentation baseline, which consequently led to a SA concentration of 36.5 g/L and productivity of 1.95 g/Lh. The results suggested that OPFH as an inexpensive and renewable source of lignocellulosic syrup is advantageous for the economic production of SA.