The Optimization Study Of High Cell Density And Protective Agents Of Bacillus Subtilis

Experimental materials is the saved laboratory strain of Bacillu Subtilis FC96,through the exploration of the strain in shake flask fermentation technology and data, to determine the optimal fermentation medium and fermentation conditions for the fermentation strain basis.The subject of FC96 fermentation medium had been studyed. Single -factor test to determine a suitable culture medium of Bacillus Subtilis FC96 .The best carbon,nitrogen sources and inorganic salts are glucose,beef extract and potassium dihydrogen phosphate. Surface analysis determined the best rate of glucose,beef extract and potassium dihydrogen phosphate. The concluded of FC96 fermentation medium components: glucose 12.11g / L,beef extract 23.31g / L and potassium dihydrogen phosphate 2.33g / L. Optimized the number of viable cells reached 2.97×109 CFU / mL, compared with the initial fermentation medium for fermentation 92.8%.The subject of shaking of the culture conditions were optimized to get the best inoculation 3%,medium volume 100mL/300mL,speed 140r/min,the initial PH 7.5,the culture temperature 35℃and incubation time 16h. Optimized shaking bacterial culture conditions increased the number of initial conditions than 34.12%.The subject of the selected strains produced by spray drying the fermentation agent, due to the high temperature drying process inventory strain had a very big impact, so the spray drying process of adding the protective agent is especially important. FC96 on this subject in the spray drying process used in the protective agent were optimized. Survival by single-factor test to the level of protection as a screening agent types of important factors that determine glycerol,Tween 80 and skimmed milk powder to improve the survival rate of FC96 significant effect, and further testing by response surface method to determine the three-factor mixed The best ratio of protective agent areTween80 1.34 g/100mL,glycerol 3.24 g/100mL and skim milk powder 9.86%. Optimize the survival rate was 79.62% , than before the case without protective agent added increased 223%.