关键词: 枯草芽孢杆菌, 发酵条件, 优化, 脲酶活性, 氨减排, 鸡粪

Abstract: In order to increase endospore amount at shake flask fermentation of Bacillus subtilis strain J530 which could produce urease inhibitors,and explore its reduction effect on ammonia emission from chicken manure,the fermentation conditions of this strain were optimized by single factor and orthogonal experiments,the bacterial agent was activated and then joined to fresh chicken manure,and the changes in the number of Bacillus subtilis,urease activity,ammonia release,ammonia nitrogen content,pH value,urea content,uric acid content and total nitrogen content were measured at 5 days after fermentation.The results showed that the optimal conditions for endospore production by shaking flask fermentation of strain J530 were as follow:Corn flour of 1.5%,soybean meal of 1.5%,MgSO₄·7H₂O of 0.3%,Na₂HPO₄of 0.2%,KH₂PO₄of 0.2%,bottle volume of 50 mL(Erlenmeyer flask 250 mL),initial pH value of 8.0,the inoculum amount of 4.0%,the culture temperature of 37℃ ,the shaker speed of 150 r/min,and the ferment time of 36 h. After optimization,the endospore content of fermentation broth increased by 20.32 times.Compared with the control group,the spore content in the test group increased by 60.29 times(P<0.01).The urease activity,ammonia release amount and ammoniacal nitrogen content were reduced by 80.78% (P<0.01),67.78%(P<0.01) and 48.57% (P<0.01).The pH value in the test group decreased by 1.35(P<0.05).The urea content,the uric acid content and the total nitrogen content increased by 24.79%(P<0.05),0.91% (P>0.05) and 8.53%(P>0.05).In conclusion,the optimal conditions for endospore production of strain J530 in shake flask fermentation were obtained,and J530 had a significant effect on reducing ammonia emissions from chicken manure.

Key words: Bacillus subtilis, Herment conditions, Optimization, Urease activity, Ammonia emission reduction, Chicken manure