Biodiversity Of Bacteria And The Effect Of Probiotics On It In Three Aquaculture Models

The biodiversity of bacteria in three aquaculture models at Shaotan Reservoir, Wuhan, was studied using 16S rDNA clone library. The effect of Rhodopseudomonas palustris and Bacillus subtilis on the biodiversity of bacteria in three aquaculture models was studied using the same method. The aquaculture models, namely, MSH1, MSH2 and MSH3, was determined by the percentage of fish in the water:grass carp, Ctenopharyngodon idella, silver carp, Hypophthalmichthysmolitrix, bighead carp, Aristichthys nobilis, puddlefish, Polyodon spathala and Carassiusauratus gibelio.The results showed:1. The sequences from the 16S rDNA clone library belonged to more than 10 phyla of bacteria:Proteobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, Verrucomicrobia, Actinobacteria, Acidobacteria, Chloroflexi, Fusobacteria, OP 10 Etc,2. The diversity analysis showed that the diversity index of MSH2 was superior than those of MSH1 and MSH3, while the diversity index of MSH3 was superior than that of MSH1. In other words, the diversity of bacteria in water increased with the increase of fish species diversity.3. The rich bacterial biodiversity was contained in the pond water which Mainly stocked grass carp. Proteobacteria was the first dominant microorganisms in the 3 models (26%,22% and 42%), Betaproteobacteria was the Advantage subgroup (10%,10% and 22%), Bacteroidetes was the second dominant microorganisms (18%,22% and 26%).4. After Rhodopseudomonas palustris and bacillus subtilis was put in the pond water, Firmicutes appeared in the clone library.5. The dominant bacterial phyla in the clone libraries of 3 time points was the same with the control group, which was Proteobacteria, Bacteroidetes and Cyanobacteria. The proportion of the 3 dominant bacterial phyla in NO.8 and NO.9 increased over time. It illustrated Rhodopseudomonas palustris and bacillus subtilis made the colony structure single, and the dominant bacterial phyla became more advantage.