Optimization on sporulation medium and culture conditions of Bacillus licheniformis
The medium formulation was screened by single-factor and orthogonal tests for Bacillus licheniformis CICC 20514 with the number and rate of spores as a screening condition,and the culture conditions were further optimized on the basis of this formulation.The results showed that the optimal combination of spore fermentation medium contains 20 g/L fructose,20 g/L soybean meal,5 g/L K2HPO4,7 g/L NaCl,0.8 g/L CaCO3 and 0.8 g/L MgSO4.The optimal culture conditions for spores production were 37 ℃,220 r/min,5％ inoculum,20％sample loading,initial pH 6.5～7.5 and 48 h of fermentation.The optimized Bacillus licheniformis CICC 20514 medium had good stability in spore number and rate.The number of spores in the fermentation reached 5.8×109 CFU/mL,which was 58 times higher than before optimization.
NETL
NSTL
万方数据
维普
