| In order to cultivate high quality and efficient bacterial liquid of Aeromonas veronii, the ingredients and dosages of nitrogen source, carbon source, inorganic salt and phosphate were optimized and combined culture medium for A. veronii inactivated vaccine adopting single-factor test, and response surface methodology experiment to determine the composition of the optimized medium and compare with the number of viable fermenting bacteria in the basic medium and immune efficacy of the inactivated vaccine, with a verification test of growth curve of the bacterium in 7 L fermentor tank. The most suitable fermentation cultivation formula for A. veronii was obtained as followed: tryptone 10.8 g/L, glucose 5.0 g/L, beef extract 3.0 g/L, KH2PO4 2.0 g/L, MgSO4 0.4 g/L, and NaCl 5.0 g/L. Under the optimized fermentation medium, the number of viable Aeromonas veronii was 5.94×109 cfu/mL, increased by 43.13% as compared with the basic medium. The relative protection rate of the inactivated vaccine prepared with the optimized medium was 77.78%, 14.81% higher than that of the basic medium. The maximal number of viable A. veronii cultured in 7 L fermentor tank for 10 h was 8.85×109 cfu/mL. A high yield of A. veronii fermentation broth was obtained through optimized fermentation medium, with low cost, high quality, and efficient. This study provided references for large-scale fermentation and cultivation of A. veronii inactivated vaccine in the future. |
