Establishment of fed-batch fermentation conditions for biocontrol bacteria B579

In order to increase the cell concentration in fermentation, feeding strategy and feeding amount were optimized. The result showed that glucose feedback feeding strategy is the best one, and glucose concentration should be controlled at 6.0 g/L during the fermentation of B. subtilis B579. The final cell concentration was 9.5×109 CFU/mL, which represented a 1.9-fold increase when compared with those of before optimized. Feed-batch fermentation in 7L fermenter was conducted under the following condition: temperature 37°C, pH 7.0, DO 10%, then supplemented glucose to the fermenter during the fermentation, and kept the glucose concentration at 6.0 g/L, after 35 h fermentation the final cell concentration was 3.9×1010 CFU/mL, which represented a 3.8-fold increase compared with those of before optimized.