生物絮团对养殖水体水质和微生物群落功能的影响

Effect of bioflocs on water quality and metabolic functions of microbial community in zero-water exchange tanks

为探讨生物絮团对养殖水体水质和微生物代谢功能的影响,采用水质分析和Biolog-ECO技术,分析了葡萄糖强化养殖水体培育生物絮团的过程中水质指标和微生物碳代谢变化特征。结果显示:(1)成熟的生物絮团有效降低了养殖水体氨氮、亚硝酸盐氮、硝酸盐氮水平,并显著提高了养殖水体的总固体悬浮物(TSS)含量。(2)对照组和生物絮团组水体微生物样品平均颜色变化率(average well color development,AWCD)在培养108 h后趋于稳定,生物絮团组AWCD高出对照组18%;同时生物絮团系统水体微生物提高了对聚合物类和碳水化合物类的代谢强度;对比2组水体微生物代谢多样性指数发现,生物絮团组Shannon-Wiener指数和丰富度指数明显高于对照组(P<0.05)。(3)2组水体微生物群落碳代谢特征PCA分析表明,主成分1(PC1)贡献度为66.9%,主成分2(PC2)贡献度为12.4%,2组水体微生物差异较大,碳代谢功能差异显著。因此,养殖水体应用生物絮团技术可以有效控制水质,增加水体微生物的代谢活性,影响水体微生物代谢功能。

In order to study the effects of biofloc on water quality and metabolic functions of microbial community in zero-water exchange tanks,glucose was used as carbon source,and water quality and carbon metabolic diversity of microbial community were investigated based on Biolog-ECO plates. The results showed that： mature biofloc reduced effectively the concentrations of ammonia nitrogen,nitrite nitrogen and nitrate nitrogen（ P〈0.05） and meanwhile significantly improved the content of total suspended solids（ TSS）.Average well color development（ AWCD） reached stationary phase after 108 h cultivation in control and floc treatments,and the floc treatment was 18% higher than that in control group. The utilization of polymers and carbohydrates in biofloc tanks were improved. Meanwhile,the diversity indexes（ Shannon index,richness index） of the biofloc tanks were higher than those of control group（ P〈0.05）. The principal component analysis of microbial metabolic characteristics in two treatments showed that principal components 1（ PC1）accounted for 66. 9%,and principal components 2（ PC2） accounted for 12. 4% respectively. Significant differences in carbon metabolic characteristics of microbial community in the culture water were found between floc treatment and control group. Thus,biofloc technology effectively reduces the nitrogen content,and improves the metabolic activity of microbial community, and also influences the function of microbial community in the culture water.