Studies On Anammox Bacteria Diversity、 Abundance And Influence Of Environmental Factors In Xilin River Wetland

Anammox process which is driven anammox bacteria plays an important role for biogeochemical cycle of nitrogen. Xilin River Wetland is a typical inland river wetland in Inner Mongolia plateau semi-arid region. It has special functions in keeping the banlance of grassland ecosystem and inheriting grassland culture. However, the study on anammox in Xilin River is still blank.This paper select the Xilin River wetland as a study area. The soil/sediments samples were collected along the gradient from the river center, the river-beside, the riparian low-floodplain, the riparian up-floodplainto oxbow lakes. Physical and chemical properties of sample were measured by classical methods. By extracting DNA from the samples and constructing anammox bacteria 16S rRNA gene clone library technique, we stuudied the diversity, community structure and distribution of anammox bacteria. Anammox bacteria abundance in samples was measured by real-time fluorescence quantitative PCR. And we analyed anammox bacteria 16S rRNAgene community structure and environmental factors by canoco soft.The major results are as follows:Physical and chemical properties of five samples are different.Each sample has different diversity and community structure. Brocadia genus is dominant,45.1%of total sequences.On the basis of the anammox 16S rRNA gene clone library, "Candidatus Brocadia" was the most common anammox genus in Xilin River wetland. Phylogenetic analysis of the anammox bacterial 16S rRNA genes indicated that sequences of the "Candidatus Brocadia" cluster showed82%to 99%to the 16S rRNA genes of "Candidatus Brocadia fulgida", sequences of the "Candidatus Kuenenia" cluster showed 81%to 97%identity to the 16S rRNA gene of "Candidatus Kuenenia stuttgartiensis", sequences of the "Candidatus Anammoxoglobus" cluster showed 81%to 98%identity to the 16S rRNA gene of "Candidatus Anammoxoglobus propionicus," and only one sequence of the "Candidatus Jettenia" cluster showed 83%identity to the 16S rRNA gene of "Candidatus Jettenia asiatica".The abundance of the anammox bacteria in the samples ranged froml.llxl04copies to 2.73x105copies per gram of dry weight. Correlation analysis showed that the abundance of ammonia content, water content of anammox bacteria is significant positive,and the pH is significantly negative.