Fingertprinting and Diversity of the Intestinal Bacterial Community of Crisp Grass Carp and Dang-zai Grass Carp (Ctenopharyngodon idellus) with PCR-DGGE
Abstract：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.
