Diversity Of Community Structure And Function In Sediment Bacteria From Shrimp Polycultural Ecosystems

Study on the shrimp polycultural ponds in Ningbo City, Zhejiang province. Themanagement modes of specifications and the technical maturity of aquaculture, have beenforming in the region, especially polyculture pattern of shrimp. It is the predominant orientationof health aquaculture in the future. Quantitative and qualitative analyses of bacterial floraassociated with sediment are investigated. The main results are detailed as follows:1. In order to understand the relationship between microbial enzyme activation andenvironmental factors in the sediment, six shrimp ponds were tested with the organic content,the total phosphorus, total nitrogen, microbial activity and alkaline phosphatase activity fromMay2011to Oct, in Ningbo city. The results showed that APA was significantly correlatedwith FDA, the same as the total nitrogen (ɑ=0.05) and the total phosphorus was significantlycorrelated with FDA(ɑ=0.05), but there were no correlation with environmental factors. So itmakes sense that sturdy on the relations with them.2. Study on The fluctuation of bacterial and environment factors in the sediment fromMay2012to Sept, besides that, a large amount of work also has been done to identify bacterialmakeup. The results from ponds showed:(1) The number of heterotrophic bacterial fromsediment increased to peak in Aμg, but the number of bacillus and vibrio went up to peak inJuly. the number of heterotrophic bacterial range from (45±2.3)×105to (110±5.9)×105cfu/g, thenumber of bacillus and vibrio range from (50±11.2)×104to (106±5.8)×104cfu/g and0to(23±2.7)×103cfu/g.(2) The organic content was significantly correlated with heterotrophicbacterial, but negatively with the total phosphorus. What’s more, number of bacillus wassignificantly correlated with that of vibrio.(3) The dominant bacteria was bacillus at50%approximately. The diversity index of Shannon—Wiener showed: the diversity index ofheterotrophic bacteria in polycultural pond was higher.3. The circulation from carbon, nitrogen and phosphorus is that centre discussed theeffect of microbe from the sediment. The results from ponds showed:(1) In terms of metaboliccarbon, there were a lot of species and numbers of the bacteria that metabolic amylum andglutin.(2) In terms of metabolic nitrogen, on the side of species richness, the nitrate-reducingbacteria, nitrifying bacteria and ammonifying bacteria sorted from most to least, but the biomassof nitrate-reducing bacteria was most, The second was nitrate-reducing bacteria. There were veryfew species of denitrifying bacteria (3) In terms of metabolic phosphorus, a few species and quantities of bacteria were found in experiment. On the whole, the Species richness andquantities of bacteria metabolicing phosphorus were low.