Comparison Of Bacterial Community Structure Characteristics Between Constructed Wetland And Natural Wetland

In recent years,with the development of economy,environmental problems such as river pollution,wetland destruction and global warming are becoming prominent,people should pay more attention to environmental problems.Water resource is a very important resource,the problem of water shortage caused by water pollution is more serious.Constructed wetland as a low cost sewage treatment technology that imitates natural wetland has been widely used.Natural wetland is a natural formation unique ecosystem with microbial diversity between water ecosystem and land ecosystem,it has been destroyed by human and its area is gradually shrinking.The stability of the constructed wetland and the natural wetland ecosystem were related to the diversity of the microbial community structure.The microbial community structure could monitory and exam the wetland function.In this paper,the structure of the bacterial community and the distribution and abundance of the methane anaerobic oxidizing bacteria in the constructed and natural wetlands were studied by high throughput sequencing technology.The relationship between the bacterial community structure and environmental factors of artificial wetlands and natural wetlands provide theoretical support for watershed management,wetland protection and greenhouse gas control.Constructed wetland(Baitapu River Estuary Wetland)were investigated the effects of plant types,sewage water quality and sampling depth on bacterial communities and the distribution of bacterial communities in Phragmites communis and Typha orientalis Presl.The results shown that the richness and diversity of bacterial communities grown around Phragmites communis'rhizosphere were higher than that of Typha orientalis Presl,so the rhizosphere of Phragmites communis was more suitable for bacterial survival.Correspondingly,with the increasing of sampling depth in same kind plant,the richness and diversity of rhizosphere bacteria was decreased.Additionally,the similarity analysis of bacterial communities shown that the distributions of bacterial communities in one plant were more similar than that in different plants.There were 13 phylum were found in plant's rhizospheres.The predominant microbes were Proteobacteria,Acidobacteria,Chloroflexi and Firmicutes with their relative abundance reaching as high as 55~78%.There were more than 20 class were found in plant's rhizospheres,in which the relative abundance of Alphaproteobacteria,Betaproteobacteria,Deltaproteobacteria,Gammaproteobacteria,Bacilli and Acidobacteria took up above 50%.Bettaproteobacteria was the main group in class level.Therefore,the major factors influencing the richness and diversity of microbial communities were nutrient content,plant types,sampling depth and temperature.In addition,the distribution of Anaerobic methane oxidation was found in constructed wetlands.and the 16S rRNA gene abundance of M.oxyfera-like bacteria was 1.7±0.28×10~5~3.7±0.43×10~5copies/g,the Shannon index was changed from1.05 to 1.21.The abundance of M.oxyfera-like bacteria was highest in 5cm depth of Phragmites communis,and the abundance of M.oxyfera-like bacteria was the lowest in 10cm depth of Lotus.Natural wetlands(Reed Sea Beach Scenic Spot(WH)?LiaoHe Wetland Forest Park(LH)?Waterside city wetland park(SX)?Moon Bay Wetland Park(YY)?Red Beach(HT)?Crane of reed and sea(GH))were investigated the effects of sampling sites and sampling depth on bacterial communities and the distribution of bacterial communities.The results shown that the richness and diversity of bacterial communities from lowest to highest was Moon Bay Wetland Park,Crane of reed and sea,Red Beach,Waterside city wetland park,LiaoHe Wetland Forest Park and Reed Sea Beach Scenic Spot,so the soil of Reed Sea Beach Scenic Spot was more suitable for bacterial survival.Correspondingly,the richness and diversity of rhizosphere bacteria was abundant in 30~40cm sampling depth.Additionally,the similarity analysis of bacterial communities shown that the distributions of bacterial communities in nearly sampling sites were more similar than in distantly sampling sites.There were 14 phylum were found in natural wetlands.The predominant microbes were Proteobacteria,Acidobacteria,Chloroflexi,Bacteroidetes and Gemmatimonadetes with their relative abundance reaching as high as 70~85%.There were more than 20 class were found in plant's rhizospheres,in which the relative abundance of Alphaproteobacteria,Betaproteobacteria,Deltaproteobacteria,Gammaproteobac-teria,gemmatimonadetes,Acidobacteria,Anaerolineae and Nitrospira took up above 60%,Bettaproteobacteria and Deltaproteobacteria was the main group in class level.Therefore,the major factors influencing the richness and diversity of microbial communities were sampling sites and sampling depth.In addition,the distribution of Anaerobic methane oxidation was found in natural wetlands,and the 16S rRNA gene abundance of M.oxyfera-like bacteria was3.8±0.49×10~3~9.9±0.46×10~4copies/g,the Shannon index was changed from 0.85 to 1.38.The abundance of M.oxyfera-like bacteria was highest in Red Beach,and the abundance ofM.oxyfera-like bacteria was the lowest in Reed Sea Beach Scenic Spot.To compare the bacterial community structure of constructed wetland and natural wetland,We founded the number of OTU and the richness and diversity of constructed wetlands was higher than natural wetlands.M.oxyfera-like bacteria were distributed in constructed wetlands and natural wetlands.The abundance of M.oxyfera-like bacteria 16S rRNA genes in constructed wetlands was higher than natural wetlands.