Mathematical Modeling, Automation and Control of the Bioconversion of Sorbitol to Sorbose in the Vitamin C Production Process I. Mathematical Modeling

Abstract

In 1990, the Biotechnology and the Control Systems Groups of IPT started developing a system for the control and automation of fermentation processes, applied to the oxidation of sorbitol to sorbose by the bacteria Gluconobacter oxydans, the microbial step of the vitamin C production process, that was chosen as a case study. Initially, a thirteen-parameter model was fitted to represent the batch operation of the system utilizing a nonlinear regression analysis, the flexible polyhedron method. Based on these results, a model for the continuous process (with the same kinetic equations) was constructed and its optimum operating point obtaine

Synthesis of l-Hexoses

“…Other l -ketoses have been synthesized in this manner such as l -tagatose ( 31 ) by microbial oxidation of galactitol ( 506 ), , l -fructose ( 475 ) from l -mannitol ( 176 ), l -psicose ( 479 ) from allitol ( 507 ), and obviously l -sorbose ( 452 ) by oxidation of sorbitol ( 508 ) (Scheme ) . There is considerable literature on the latter process as it is the first step of a two-step biotechnological process for preparation of vitamin C from 508 . − Many smart developments such as immobilized organisms, − thermoresistant strains, fed-batch methods, − continuous fermentation, computer-coupled substrate feeding, and using oxygen vectors have been reported. Yields are frequently over 90%, but byproducts such as d -fructose and d -mannitol can be formed, and rates can be limited …”