脆化草鱼与氹仔草鱼的肠道细菌群落PCR-DGGE指纹图谱及多样性分析

摘要

确定地理来源是水产品跟踪和追溯的一个重要指标,基于鱼类肠道细菌16S核糖体rRNA基因(16S rDNA)构建的PCR-DGGE指纹图谱可标示鱼类来源.本研究采用PCR-DGGE技术构建了中山脆化草鱼和茂名氹仔草鱼(Ctenopharyngodon idellus)肠道内容物和肠道壁群落的PCR-DGGE指纹图谱.肠道内容物DGGE图谱显示,脆化草鱼和氹仔草鱼分别有17条和15条可鉴别的条带；脆化草鱼特异条带代表3种未培养细菌GU301246.1、FJ675051.1和GU293197.1,氹仔草鱼特异条带代表未培养细菌AY578409.1和GU301246.1.脆化草鱼的肠道壁前肠与中肠、中肠与后肠、前肠与后肠的DGGE图谱相似性依次为50.5％、54.3％和33.2％,氹仔草鱼的肠道壁前肠与中肠中肠与后肠、前肠与后肠的DGGE图相似性分别为36.1％、47.7％和15.4％.脆化草鱼的前肠、中肠和后肠的DGGE图谱的相似性远大于氹仔草鱼.脆化草鱼和氹仔草鱼的肠道群落PCR-DGGE指纹图谱有助于这2种草鱼产品的跟踪和销售.%The determination of geographical origin is a demand of the traceability system of import-export food products, and 16S ribosomal rRNA (rDNA) PCR-DGGE fingerprinting based on fish intestinal microbia has been considered to trace the fish sources. For this purpose, PCR-DGGE technology were used to detect the variation in bacterial community structures in the intestinal contents and intestinal wall of Crisp grass carp (CGC)(Ctenopharyngodon idellus) from Zhongshan and Dang-zai grass carp (DGC)(C. idellus) from Maoming district. The V3 region of bacterial 16S rDNA from fish was amplified by PCR and was analyzed by DGGE. It's demonstrated in the DGGE profiles of intestinal contents that there were 17 bands in the CGC and 15 bands in the DGC, 11 bands co-exiting in both CGC and DGC. The results of molecular identification of specific bands showed that specific bacteria of CGC included uncultured bacteria GU301246.1, FJ675051.1 and GU293197.1, specific bacteria of DGC included uncultured bacteria AY578409.1 and GU301246.1. It's demonstrated in the DGGE profiles of intestinal wall that there were 18, 19 and 16 bands in the foregut, midgut and hindgut of CGC, and 18, 13 and 13 bands in the foregut, midgut and hindgut of DGC. There were 6 bands co-exiting in the foregut, midgut and hindgut of CGC and 3 bands co-exiting in the foregut, midgut and hindgut of DGC. The intestinal wall DGGE profiles displayed that similarities between foregut and midgut, midgut and hindgut, foregut and hindgut of CGC were followed respectively by 50.5%, 54.3% and 33.2%, and those of DGC were 36.1%, 47.7% and 15.4%, respectively. The similarity among the foregut, midgut and hindgut in the DGGE fingerprint clustering of CGC was much larger than that of DGC. The results of this paper demonstrated that PCR-DGGE method could be a traceability tool which provides grass carp products with a unique fingerprinting and makes it possible to trace back the CGC and DGC to their original location.