于2008年6至10月逐月调查研究了新型复合池塘循环水养殖系统各塘水体理化和微生物分子特征.通过提取水样中细菌总DNA,扩增其16S rDNA基因V3区,再经DGGE分析获得图谱,选择其中主要的13条特征条带进行克隆测序.研究结果表现为,随水流方向(Pl→P5),各循环塘溶氧(DO)和透明度(SD)依次呈明显下降趋势,而NH4~+-N,TP和COD_Mn水平呈明显上升趋势;与对照塘相比,循环塘DO和SD升高,COD_Mn和营养盐水平降低.DGGE图谱分析显示,各养殖塘微生物种类丰富,循环塘与对照塘的群落结构存在明显差异,且差异主要表现在较弱的条带上;13条特征条带的测序结果表明,池塘优势菌群分属4个门:放线菌门(Actinobacteria)、变形菌门(Proteobacteria)、蓝细菌门(Cyanobacteria)和拟杆菌门(Bacteroidetes),其中有2条属于蓝细菌门的条带特定分布于对照塘.典型对应分析(CCA)排序结果显示,DGGE图谱条带分布与理化因子密切相关.与传统池塘养殖相比,该养殖模式有助于改善养殖池塘微生态环境.本研究旨为池塘微生物群落结构及其功能关系研究提供借鉴.%Aquaculture has been one of the fastest growing segments of global food production sector in recent decades. With the rapid development, it also leads to many environmental problems. For example, both per unit area yield of aquatic products and their quality has declined continuously.It is important that well-balanced systems be developed that are sustainable. Constructed wetlands (CWs) are ecologically beneficial, low-cost treatment alternatives, proven capable of reducing suspended solids, 5-day biochemical oxygen demand (BOD5), nitrogen, phosphorus and heavy metals from wastewater of many sources. In the present paper, the physicochemical and microbial characteristics of culture ponds in an Integrated Pond Recirculating Aquaculture System (IPRAS)based on constructed wetland were investigated during the period of June to October 2008. In the study, 16S rDNA gene V3 region was amplified from total DNA of bacteria in water samples and followed by DGGE. Sequences of 13 dominant bands excised from DGGE gels were analyzed and the closest relatives of obtained sequences were all uncultured bacterial clone in GenBank._The results indicated that levels of dissolved oxygen (DO) and transparency (SD) showed a decreasing trend along the flow direction (PI→P5), while an opposite trend for ammonium nitrogen (NH4+-N), total phosphorus (TP) and chemical oxygen demand (CODMn). The recirculating treatment increased water DO and SD, while decreased pH, CODMn and nutrients compared to the control. The DGGE fingerprints suggested a high species richness of microorganism and the clustering dendrogram revealed distinct differences in microbial community structure between the recirculating and control ponds. By the phylogenetic tree,the 13 dominant bands were grouped into four phyla: Actinobacteria, Proteobacteria, Cyanobacteria and Bacteroidetes, among which two cyanobacterial bands particular distributed in the control. The results of canonical correspondence analysis (CCA) also revealed that the distribution characteristics of DGGE fingerprints was strongly associated with the measured environment. Hereby, conclusions could be reached that the recirculating aquaculture system, as a new cultivation pattern, effectively improved the microbial environment of the culture ponds and benefited pond aquaculture. The results also provided basic references for analyzing the microbial community structure and their functional relationships in further study. [Joural of Fishery Sciences of China, 2011, 18(2):407-415]
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