| The Ebinur Lake Wetland is the largest lake in xinjiang. It also is the most representative terminal typelake wetland of inland river basin in arid areas. The Ebinur Lake wetland is given priority to the lakewetland and set the lake wetland, river wetland and marsh wetland in an organic whole. At the same time, italso has a very special geographical location and ecological niches. Meanwhile, the succession process ofwetland ecosystem causing by the increasing and decreasing of the lake area had become a barometer toreflect the ecological environment improvement and deterioration in the Ebinur Lake Wetland.What’s more,research on different types of wetlands microbial diversity in the Ebinur Lake Wetland is also more less, itis controversial on the problem of whether the microbial community is rich.In this study, total DNA was directly extracted and purified from the soil of three different wetlandtypes, as the lake wetland, river wetland and marsh wetlands in the Ebinur Lake wetland.16S rRNA genewas amplified using bacterial primer set Eubac27F and Eubac1492R. The positive clones containing16SrRNA gene were screened through the process of connection, transformation and blue white spot screening.The16S rRNA gene clone library was constructed. Positive clones were identified by amplified rDNArestriction analysis (ARDRA) using Msp I and Afa I. Further sequencing and phylogenetic analysis wereconducted to elucidate the bacterial diversity and community composition in the Ebinur Lake WetlandNational Nature Reserve.In this study, although about160clones were analysed in each of the library, the coverage was verylower. The results showed that the Ebinur Lake Wetland soil bacterial community has a abundant diversity.The research data showed that the soil procaryote microbiology in the Ebinur Lake Wetland was abundant.The Procaryote microbiology can be classified into the following phyla, such as Chioroflexi, Cyanobacteres,Proteobacteria, Firmicates, Actinobacteria, Bacteroidetes, Verrucomicrob, Gemmatimonadetes,Acidobacteria, Chlamydiae, Deinococcus-thermus, Planctomycetes and so on. Among them, theProteobacteria and Bacteroidetes were the absolute advantage phyla in the Ebinur Lake three different typesof wetlands. In the lake wetland, the most abundant phylum was Proteobacteria, followed by Bacteroidetes.In the river wetland and marsh wetland, the most abundant phylum was Bacteroidetes, followed byProteobacteria. The study of similar sequence alignment showed that the Ebinur Lake Wetland soil had thesequences of the Proteobacteria, it is consistent with the study of soil in salt lakes, Antarctica lakes, and thedeep sea of the Indian Ocean. In other words, the Proteobacteria has the characteristics of halophilic, coldresistance, resistance to high pressure and show a strong global adaptability and variability.The soil procaryote microbiology community structure similarity was extremely low in the EbinurLake Wetland three different wetland types by comparing the wetland prokaryotic microbiologycommunity structure. BRC1, Chlamydiae and TM7were the specific phyla of the lake wetland.Verrucomicrob and Gemmatimonadetes were the specific phyla of the river wetland. Planctomycetes,Deinococcus-Thermus and Chlorobi were the specific phyla of the marsh wetland. It was worthy to noticethat we also found a large number of unclassified bacteria in the community structure. The proportion ofthem in the lake wetland, river wetland and marsh wetland was21.9%,6.0%and11.8%, respectively. Theproportion of sequence was20.6%,8.0%and14.8%. Unclassified bacteria almost became the third largestphylum in addition to the Proteobacteria and Bacteroidetes. The result showed that the Ebinur LakeWetland exist a certain amount of new unknown taxon and classification of bacteria.In this study, the correlation among the prokaryotic microbial community structure change in theEbinur Lake Wetland, the soil physicochemical properties and soil heavy metals were analyzed using SPSSsoftware. The result showed that, available potassium and chromium had a significantly correlation withBacteroidetes, the correlation coefficient was0.991, the significant level were0.021and0.023.Cyanobacteria had a significantly negative correlation with pH, the correlation coefficient was-1.000, thesignificant level was0.013. Meanwhile, Cyanobacteria had a relatively strong correlation with organic matter and available nitrogen. Verrucomicrob and Gemmatimonadetes had a significantly positivecorrelation with organic matter and available nitrogen, the correlation coefficient were0.998and1.000, thesignificant level were0.039and0.014. Danin-Thermus, Planctomycetes and Chlorobi had a significantlypositive correlation with zinc, all the correlation coefficient was1.000, all the significant level was0.020.In conclusion, soil fertility levels, salinity, pH value and soil heavy metals influenced the Prokaryoticmicrobial community structure in the Ebinur Lake Wetland. Moreover, changing of the Prokaryoticmicrobial community structure reflected the soil quality from the side.16S rRNA gene in prokaryotic organisms tend to have multiple copies at the same time, and the genesequence among the copy is not completely consistent. Therefore, the study of prokaryotic microbialmolecular ecology on16S rRNA genes of community diversity analysis will cause a certain degree ofovervalued. zhou and others in Wuhan virus Institute of Chinese academy of sciences detailedly analysedand researched the the copy number of16S rRNA genes and genome internal heterogeneity and found that16S rRNA gene exists heterogeneity and the degree of heterogeneity is different in different regions.In thisstudy, as the number of clones had been analysed were less, the average number of clones representing byeach sequence under the3.61, which is proposed. At the0.03level (97%homology is classified as a OTU),except Proteobacteria, Bacteroidetes and Chioroflexi bacteria, the OTUs of other sequences mostly onlyhad a clone, and under this level because of the heterogeneity of community diversity of16S rRNA geneovervalued rate was5.8%. Therefore, the analysis in this study are in270OTUs OTUs in the actualenvironment community diversity should be254, and the16S rRNA gene heterogeneity mainly focused onthe most abundant phyla. It is the strategy of microorganism to adapt to the Ebinur Lake Wetland soil salineenvironment, has different copy number can exert its functions in different environment to improve itsadaptability. In short,16S rRNA genes has different degree of heterogeneity in different community types,advantage community is higher and it is not obvious on the microbial community structure andcomposition. |
PDF Full Text Request