Process development of oxygen-demanding reactions utilizing a simple design with parallel glass tube reactors - Evaluated using Gluconobacter oxydans (DSM 24525)

To investigate the possibility of using simple glass tubes as reactors for oxygen-demanding reactions, a setup was assembled to study the initial rate of conversion of glycerol to dihydroxyacetone (DHA) using Gluconobacter oxydans. Several parallel 10 mL glass tubes were incubated in a temperature-controlled shaker. The concentration of DHA was determined using a fast spectrophotometric HPLC-based method that could process 3 samples/min. It was shown that the obtained results were reproducible and the reaction rates remained constant throughout the reaction. Further, the system reached a high volumetric activity of 15.48 g DHA L-1 h(-1) consuming 86 mmol L-1 h(-1) oxygen before the system became mass-transfer limited, indicating a high diffusion of oxygen. It was concluded that the reactor system is well suited for process development where the requirement for oxygen is high and that the assay developed can be used to determine the initial rate of DHA production