枯草芽孢杆菌的培养条件及对水质的净化作用

研究了枯草芽孢杆菌(Bacillus subtilis Cohn,1872)(菌株编号:LB-B3)的培养条件及其在净化对虾养殖池水样方面的效果。实验分别设置了9个不同的pH值梯度(pH 2～10)和6个不同接种量梯度(0.3%、0.5%、1%、3%、5%和7%),以吸光值(OD)为生长指标,进行了枯草芽孢杆菌培养条件的优化实验;同时又设置了5个不同接种浓度(0 CFU/mL、5.2×104CFU/mL、1.04×105CFU/mL、1.56×105CFU/mL和2.08×105CFU/mL)接种待处理水样,测定了96 h内化学耗氧量、亚硝酸氮、氨态氮和溶氧等4个水质指标的变化情况。结果表明:pH=7.0、接种量为7.0%时,OD值最大;枯草芽孢杆菌能显著净化水质,但使用后会暂时性增加耗氧。

Cultivation Conditions and Application in Water Purification Effect of Bacillus subtilis

Cultivation conditions and purification effect on water from shrimp pond of Bacillus subtilis Cohn(strain code:LB-B3)were studied.In the experiment,9 pH values(pH 2~10)and 6 inoculating contents(0.3%,0.5%,1%,3%,5% and 7%)were set to optimize the cultivation conditions of B.subtilis,with OD value as measure index.In 5 concentrations(0 CFU/mL、5.2×104 CFU/mL、1.04×105 CFU/mL、1.56×105 CFU/mL and 2.08×105 CFU/mL)were B.subtilis inoculated to water samples,and 4 water quality indices(nitrite nitrogen content,COD,ammoniac nitrogen content and dissolved oxygen content)were tested during 96 hours to determine the optimal applying concentration of B.subtilis.The results indicated that,the OD value was the highest with 7% inoculating content and pH value 7.0,and B.subtilis did can improve water quality obviously,although dissolved oxygen would decrease temporarily.