Study On The Microbial Diversity In The Water Envirenments Of Natural Wetland

Wetlands play great roles in the environments. The microbial diversity is determined by the unique water characteristics and conditions.The samples of this study were collected from wetland along the old course of yellow river in Henan, Yellow River Delta in Shandong, Bai Yang-dian wetland in Hebei province. Microbia were obtained by filtering. Then their stucture and diversity were analysed based on PCR-DGGE.The results were shown as follow:1 The water characteristics of different type wetlands are obviousely different.Microbial cultivation results showed that the total cultivatlbe microbial numbers in Bai Yang-dian wetland were the highest and those along the old course of yellow river were the lowest, among which the numbers of bacteria in all samples were the highest.2 The bacterial diversity in the three wetlands was analysed using molecular biological methods such as PCR-DGGE and 16S rDNA sequencing. The highest diversity of bacteria was detected in Yellow River Delta followed by wetlands in Bai Yang-dian and along the old course of yellow river. Similarity analysis based on DGGE profile indicated that samples from the Yellow River Delta and Bai Yang-dian wetland clustered more closely than those from the old course of yellow river. Almost all the bands were recovered from the DGGE gel and sequenced. Phylogenetic tree based on these sequences showed that nine distinct lineages of bacteria were in the three wetlands belonging to Actinobacteria(8.6%), Cyanobacteria(2.8%), Verrucomicrobia(5.7%), Alphaproteobacteria(2.8%), betaproteobacteria (17.1%),Flavobacterium (2.8%), Bacilli(11.4%), Gammaaproteobacteria(31.4%), Sphingobacteria(8.6%), in which Gammaaproteobacteria were the most bundant community in all the samples, while Gammaproteobacteria,Bacilli and Actinobacteria were generally detected from the three wetlands.3 The diversity and similarity of fungi were analysed using the same metheds as above. The results showed the similar trend as bacteria's. Four major distinct lineages belonging to Chytridiomycetes(16.2%), Ustilaginomycetes(5.4%), Zygomycetes(2.7%) and Urediniomycetes(21.6%) were detected from the samples, in which Urediniomycetes existed in all the wetlands, but distributed in different taxons. Due to unspecific primers used in the fungi PCR, half of the sequences were not belong to fungi. No archeae were detected from all the samples.4 The significant difference in the microbial communities suggested that the types, location, and the water charecteristics in different wetlands formed their unique water environment and strongly influenced their microbial structures.5 Quantification results of functional genes relating with notriogen cycling showed that gene amoA was the most abundant in all the samples. The copies of these functional genes were positively correlated with the contents of NH3-N and total N.