Temperature gradient-based high-cell density fed-batch fermentation for the production of pyruvate oxidase by recombinant <italic>E. coli</italic>.

Pyruvate oxidase (PyOD) is a very powerful enzyme for clinical diagnostic applications and environmental monitoring. Influences of temperature on cell growth, plasmid stability, and PyOD expression during the PyOD fermentation process by recombinant <italic>Escherichia coli</italic> were investigated. Based on the influences of temperature on the physiological metabolism, a novel high-cell density fed-batch cultivation with gradient temperature decrease strategy for effective PyOD production was achieved, under which the biomass (OD600) of recombinant <italic>E. coli</italic> could reach to 71 and the highest PyOD activity in broth could reach to 3,307 U/L in 26 hr fermentation. [ABSTRACT FROM AUTHOR]