Sunday, August 1, 2010
Pacific Concourse (Hyatt Regency San Francisco)
Some studies has suggested the use of autochthonous or indigenous benefic microorganisms for that purposes and therefore an option to the integral management of the microflorae is to know bacterial communities dwelling in both, the gut of cultured organisms. Due to commercial significance, some members of genus Macrobrachium are among the better known fresh water prawns. Although several studies have been developed on the probiotic potential and pathogenicity of some microorganisms, no evidences have been published about the gut-associated bacterial community for this species. Moreover and possibly as a consequent of the lack of this information, there are not culture programs aimed to the production and conservation of prawn. The present work was conducted for studying the gut-associated bacterial florae in the prawn M. carcinus L, employing culture-dependent and independent methods. Metagenomic mgDNA was extracted from gastrointestinal track. Several isolates in different selective media were also obtained from these samples. mgDNA was amplified with universal and Firmicutes-specific primers targeting hypervariable regions of the 16S rRNA gene. After separation of amplicons by DGGE a total of 17 phylotypes were observed with universal primers and 7 with Firmicutes-specific primers. Phylogenetic analysis of sequences obtained from recovered bands showed that 78% of identified taxa classified as Proteobacteria being Pseudomonaceae the predominant family. Other families from the phylum Firmicutes like Staphylococcaceae, Carnobacteriaceae, Streptococcaceae and Moraxellaceae were also identified. Isolated strains were identified as members of the Enterococcaea and Lactobacillaceae families. Finally.
Key words: Macrobrachium carcinus, bacterial community, gut, PCR-DGGE.