Optimization of medium formulation and conditions for growing biocontrol bacteria ZB-6 using Uniform Design

ZB-6,a Bacillus subtilis strain obtained from healthy tomato leaf,showed a strong inhibitory activity toward plant pathogens.The Uniform Design was used to optimize the medium formulation for ZB-6 fermentation in shaking flasks.The identified formulation was∶sugar 4.82 g,beef extract 3.15 g,bean cake powder 11.01 g,ammonium nitrate 5.21 g,dipotassium hydrogen phosphate 5.04 g,and potassium dihydrogen phosphate 2.84 g.It increased the ZB-6 biomass concentration from 2.36×108 to 6.7×109 cfu·mL-1.