Optimizing Fermentation of Biocontrol Bacterium Bacillus cereus BCCY-22

  Objective   Conditions for optimal fermentation of Bacillus cereus BCCY-22, which is known to be capable of effectively controlling a variety of nematode diseases, were determined.

  Methods   Using OD₆₀₀ of the fermentation broth as the indicator, optimal culture conditions for the process were determined with a single factor and response surface experimentation.

  Results  High temperature, low initial pH, and restricted oxygen supply significantly governed the bacterial growth. The finalized process was carried out at 21.5 ℃ with an initial pH at 7.3 and inoculation of the seeding broth at 3% to fill 23% in a flask for 36 h.

  Conclusion   The optimization shortened the fermentation time by 6 h and increased the biomass by 135.94%. The improvements materially provided the basis for industrialized utilization of B. cereus BCCY-22 as a biocontrol agent.