Regeneration Wet Ground Cattails Rhizosphere Bacterial Diversity Studies

Abstract:In recent years, the technology to reuse reclaimed water largely solved the contradiction between supply and demand of water resources in Beijing, but its unique water features COD concentration is low, high nitrogen and phosphorus content, including volatile organic components of antibiotics and halogenated hydrocarbon will inevitably affect the urban water ecological environment. At present, the constructed wetlands have become a important measure to purifying water quality and promote water ecological restoration. Microorganisms as the main driving force of water purification, plays an irreplaceable role in the degradation of pollution. This study based on the typical stream wetland which supplied by reclaimed water, using T-RFLP and clone library construction technology to analysis the community of bacteria and ammonia oxidizing bacteria and their response to environmental factors of rhizosphere of cattail. The results show that:(1) Bacteria samples digestioned by Msp I and Hha I enzyme in T-RFLP can reveal a higher abundance. Eight points of rhizosphere bacteria sample in the study area is divided into four groups, including16types of advantage T-RFs.66bp as a major advantage bacterium group showed a trend of first reduce and then increase, it is closely related to water quality variation. Occasional groups exist or not and its abundance can obviously reflect the effects of reclaimed water quality on bacteria groups, the group II and III groups has different distribution pattern, and the group Ⅰ and Ⅳ have similar distribution pattern. From the point of environmental response, both group Ⅰ and Ⅳ have closely relationship with the biological cycle of TOC and the heavy metal; The group Ⅱ do not have the same distribution pattern with existing environmental factors; The group Ⅲ has a close relationship with the biological circulation of phosphorus, ammonia and DO; Different environmental parameters make different influence for the space distribution of bacterial community structure.(2)16S rDNA clone library of bacterial includes11groups of bacteria, the most advantage group is Proteobacteria, and Bacteroidetes, Firmicute, Acidobacteria, Verrucomicrobia, Gemmatimonadetes, Planctomycetes, Chloroflexi, Spirochaetes, Chlorobi, Cyanobacteria, another13.57%clone have not blast the specific species.(3) The eight cattail rhizosphere AOB community can be divided into4types, including11types of advantage T-RFs,52bp is the most advantage T-RFs types of group II;68bp is the most advantage T-RFs type of group Ⅳ.The downstream water quality isin favour of68bp bacteria growth. All of the4groups haveoccasional groups, more occasional groups appear in water environment, just affected by the water quality characteristics of reclaimed water. Then the advantage and occasional groups will reduce with the purificationof water quality, diversity and abundance of the group II is higher; And the superiority and the occasional of the group III is reduced affected by hydrating significantly; After the large space purification scale (>3000m), the group IV find more than advantages and occasional. The group Ⅲclose to the biological cycle of ammonia nitrogen, Cd, pH and TDS; The group I take part in the cycle of heavy metal, nitrogen and phosphorus. The group Ⅱ and Ⅳ do not have the same pattern with the existing environmental factors.(4) Phylogenetic analysis of amoA clone library of cattail rhizosphere AOB shows that AOB community is mainly contained Nitrosospira and Nitrosomonas, Nitrosospira as the dominant fungi genera, mainly participate in nitrification in the aquatic ecosystems nitrogen cycle.