Abstract:

The effect of different temperatures on the growth of Bacillus subtilis ZJF-15, substrate consumption and
β-glucanase production was studied by conducting batch fermentation experiments in a 5-L fermentation tank. The
fermentation conditions were determined as 400 r/min, 1.0 L/(L·min), 7.0, 5%, 0.6 and 35–37 ℃ for rotating speed,
ventilation rate, initial fermentation pH, inoculum quantity, medium loading coefficient and culture temperature, respectively.
The results showed that increased culture temperature led to a higher reaction rate, accelerated bacterial growth and
metabolism, earlier production of β-glucanase, faster enzyme inactivation, shortened fermentation period and finally reduced
production of β-glucanase. The kinetic equations for bacterial growth, substrate consumption and β-glucanase production of
Bacillus subtilis ZJF-15 were established by batch fermentation.

Key words: Bacillus subtilis, β-glucanase, batch fermentation, temperature, kinetics