枯草芽孢杆菌对海水鱼塘生态因子的影响

为探讨枯草芽孢杆菌(Bacillus subtilis)在鱼类养殖池塘中的生态作用,采用直接往养殖水体中投放该制剂的方法,研究分析微生物数量及其与环境因子的相关关系。结果显示,枯草芽孢杆菌,实验池数量为0.35×10~3~1.45×10~3cfu/m L,对照池为0.04×10~3~0.08×10~3cfu/m L;浮游植物生物量,实验池为0.094~1.521 mg/L,对照池为0.103~0.763 mg/L,实验池中枯草芽孢杆菌数量和浮游植物生物量均高于对照组。试验鱼塘中枯草芽孢杆菌与硅藻数量呈显著正相关,相关系数0.844(P0.05);当溶氧≥6 mg/L时,枯草芽孢杆菌与亚硝酸盐氮含量呈显著负相关,相关系数-0.915(P0.05)。溶氧过低(2 mg/L)时,枯草芽孢杆菌对亚硝酸盐氮、氨氮没有明显的降解作用;溶氧≥6 mg/L时,对亚硝酸盐氮、氨氮的降解作用明显。研究表明,投放适量浓度的枯草芽孢杆菌能有效改善养殖水体状况,对水质起到进一步净化作用。

Effects of Bacillus subtilis on the ecological factors in marine fish pond

To discuss the ecological effects of micro-ecological agents of Bacillus subtilis into marine fish pond , the relationship between microorganism quantity and environmental factors was investigated in marine fish pond by artificially adding method.The results showed that the quantity of Bacillus subtilis amounted to 0.35 ×103-1.45 ×103 cfu/mL in the experiment group, and 0.04 ×103-0.08 ×103 cfu/mL in the control group; the phytoplankton biomass (0.102 6-0.763 2 mg/L in the experiment group and 0.093 6-1.520 9 mg/L in the control group ) were both significantly higher in the experiment group than those in the control group .In the experiment group; the Bacillus subtilis amounts were significantly positive correlative with the diatom abundance (correlation coefficient =0.844, P<0.05), but those were significantly negative correlative with the nitrite nitrogen concentration ( correlation coefficient =-0 .915 , P <0 .05 ) , if the dissolved oxygen concentration was more than 6 mg/L.In addition, if the dissolved oxygen concentration was too low (<2 mg/L), there was no degradation effect of Bacillus subtilis on ammonia nitrogen and nitrite nitrogen in the seawater , but there was a significant degradation effect of Bacillus subtilis on ammonia nitrogen and nitrite nitrogen when the dissolved oxygen concentration reached to 6 mg/L or more .Thus it can be inferred that the appropriate concentration of Bacillus subtilis can effectively improve the condition of aquaculture water , and further purify the water quality .