Study On Microorganism Of MBR Treatment For Aquaculture Waste Water

In this study, aiming emphatically at the characteristic of the membrane biological reactor(MBR) aquaculture waste water treatment process,the microbial community structure and dominant bacteria of the process were researched with molecular biological method,such as terminal restriction fragment length polymorphism(T-RFLP),high-throughput sequencing and analysis of 16 S r DNA sequence. At the same time, an aerobic denitrifier was isolated from MBR. And identify the denitrification performance the strains.The cultured bacteria was analyzed by 16 S r DNA sequence identification.This paper hopes that the research can provide the reference for the MBR reactor bacterial structure research and MBR debugging operation. The results of the study are as follows:(1) Stable operation, the MBR reactor effluent could meet the The first clas s discharge standard from in freshwater aquaculture wastewater discharge of "fres hwater ponds water discharge requirements". Especially, MBR has a good remova l effect for COD(At least 91%) and NH4+-N(At least 91%) from aquaculture was tewater pollutants.(2) The startup process of MBR had microbial succession. The succession o f microbial the demise of both the original dominant populations, but also to e nhance the advantages of the new population.(3) The function of the dominant population status in dynamic change.It sh ows that,the MBR reactor main advantage bacteria in aquaculture wastewater trea tment system are as follows: Pseudomonas sp., Acidobacteria_bacterium, Aeromon as_hydrophila, Azonexus_sp, Candidatus_Halomonas, Candidatus_Microthrix, Chlor oflexi_bacterium, Flavobacterium_cauense, Flavobacterium_sp, Gemmata_sp, Lacto coccus_raffinolactis, Methylosinus_sp, Nitrosomonas_oligotropha, Pythium_ultimum,Rhodoblastus_acidophilus, alpha_proteobacterium, filamentous_bacterium, gamma_proteobacterium, uncultured_delta_proteobacterium, uncultured_soil_bacterium, unc ultured_Saprospiraceae_bacterium, uncultured_Bacteroidetes_bacterium, uncultured_Geothrix_sp, uncultured_Xanthomonadales_bacterium.(4) Microbial species were abundant in the inoculation period and the stable running period of MBR, Similar levels of microbial diversity was 0.97, the result of similarity indices analysis as follows : OUT(Operational Taxonomic Unit s) 345,Ace 1249,Chao 782, Shannon3.05, Simpson 0.1661.(5) 9 strains were identified from the MBR reactor by of 16 S r DNA sequ ence analysis, It shows that, Pseudomonas sp, Raoultell-a terrigena, Exiguobacter ium acetylicum, Klebsiella ornithinolytica, Klebsiella sp, Enterobacter ludwigii, un cultured Raoultella sp, uncultured Klebsiella.sp, Prototheca wickerhamii, Raoultell a planticola, arthrobacter sp, Arthrobacter nicotianae.(6) Demonstrated the existence of a la-rge number of uncultured microorgani sms in MBR, Separation and identification of microorganisms is only a small pa rt of microbiology.(7) The method of acclimating aerobic denitrifying bacteria is studied from activated sludge by MBR system on treatment of aquaculture waste water.One str ain aerobic denitrifying bacteria, was isolated from the activated sludge. It was identified as pseudomonas sp based on its biochemical/morphological characteristi cs and physiological analysis of its 16 Sr RNA sequence. The denitrifying capabilit y of the strain was studied in batch culture under aerobic condition. The results showed that the nitrate in the culture could be efficiently removed by the strain.Denitrification process of the mainly occurred in the exponential phase. The stra in had obvious effect on nitrate removal. It had good removal effect on nitrate,ammonia nitrogen from aquaculture wastewater.