Abstract:

The kinetics of the batch fermentation of Bacillus licheniformis for cypermethrin degradation in a 10 L fermentor
was analyzed. Cell growth, the production of cypermethrin-degrading esterase, substrate consumption and cypermethrin
degradation were investigated when the fermentation conditions were as follows: filling coefficient, 0.65; inoculum
amount, 6.25% (V/V); initial pH, 7.5; temperature, 37 ℃; and rotation speed, 300 r/min. Kinetic models for the growth of
Bacillus licheniformis B-1 , cypermethrin-degrading esterase production, substrate (glucose) consumption and cypermethrin
degradation were established through nonlinear regression using Logistic equation, Luedeking-Piret equation, Luedeking-
Piret-Like equation and first-order kinetic model. The results showed that the predicted values from these models were
in good agreement with the experimental data and these models could provide a reasonable description for the batch
fermentation process of Bacillus licheniformis B-1 strain.

Key words: cypermethrin, batch fermentation, degradation, kinetic models