微生态制剂对养殖后期虾池水质及细菌群落的影响

Effect of probiotics on water quality and bacterial community in shrimp pools at later stage of cultivation

水产养殖可持续发展的要求促进了微生态制剂的研究，为了解微生态制剂MP-1和MP-2的应用效果及其作用机理，选择处于养殖后期虾池开展应用试验，每周从试验池中采样分析水体CODMn、氨氮、亚硝酸盐、硝酸盐和总氮的变化，并用PCR-DGGE分析了虾池细菌群落结构的变化。结果显示：投加微生态制剂MP-1和MP-2后1周，虾池亚硝酸盐均低于0.01 mg· L^-1，2周后虾池氨氮分别稳定在0.26～0.33 mg·L^-1和0.35～0.48 mg·L^-1，试验过程中水体硝酸盐和CODMn保持稳定，总氮的去除率达到34.1％以上；虾池的主要细菌类群和细菌群落结构发生显著变化。结果表明：微生态制剂MP-1和MP-2可显著改善养殖后期虾池水质，其净水作用可能是微生态制剂调控虾池土著微生物群落变化后的共同作用结果。

The research of probiotics for aquatic animals is increasing with the demand of aquaculture ＇s sustainable development .To evaluate the effect of new developed probiotcs MP-1 and MP-2 and investigate their water purifying mechanism, experiments were conducted in shrimp pools at the later stage of cultivation .Water samples were sam-pled from the shrimp pools to determine the COD Mn , ammonia, nitrite, nitrate and total nitrogen every week , and the bacterial community structure in shrimp pools were analyzed by PCR-DGGE.Results showed the contents of nitrite in shrimp pools were all below 0.01 mg· L^-1 after a week when the probotics were added .The contents of ammonia in shrimp pools kept within 0.26 mg· L^-1 to 0.33 mg· L^-1 and 0.35 mg·L^-1 to 0.48 mg· L^-1 after two weeks when pro-biotics MP-1 and MP-2 were added.The contents of nirate and COD Mn remained statistical unchanged in the experi-ments.And the total nitrogen was found a removal rate over 34.1%.PCR-DGGE showed the main bacterial popula-tions and bacterial community structure changed significantly .The results suggested that probiotcs MP-1 and MP-2 could significantly improve the water quality while they were used in shrimp pools .It might be a result of the change in autochthonal bacterial community caused by probiotics .