Optimization of Continuous Bioconversion Process of Glycerol to 1,3-Propanediol

Abstract

This paper addresses the optimization of continuous bioconversion process of glycerol to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae. The studied bioprocess is a complex nonlinear system that involves the gene regulation for dha regulon, enzymecatalytic kinetics on the reductive pathway, the active transport of glycerol and (passive) diffusion of 1,3-PD across the cell membrane, and the inhibition of glycerol dehydratase (GDHt) and 1,3-propanediol oxidoreductase (PDOR) by 3-hydroxypropionaldehy (3-HPA). We first propose a nonlinear optimization model that can maximize the production rate of 1,3-PD. Then the optimal solution of this optimization problem is obtained by using an interior point method. In this approach a sequence of barrier problems are solved iteratively. We finally obtain the maximum production rate of 1,3-PD increased more than 22.86 times its initial value.