Isolation Of Halomonas Sp. And Diversity And Abundance Of AnAOB In Badain Jaran Desert Lake

Badain Jaran desert is located in Alashan Plateau of the Inner Mongolia Autonomous region,which is the second largest desert in China.There are numerous of megadunes and lakes in the Badain Jaran desert,where a wide variety of microbes live.The purpose of this study is to discover the culturable Halomonas sp.strains and uncultured anaerobic ammonia oxidizing bacteria?AnAOB?by means of pure cultivation and molecular biology methods.In this study,halophilic bacteria strains were isolated from Badain Lake?West?by means of pure cultivation.The AnAOB community structures and abundance in eight sediment samples were analyzed by molecular biology methods.The methods and results were as follows:?1?In this study,21 moderate halophiles were isolated from Badain Lake?West?through dilution-plate method,which have semblable morphological features with Halomonas strains.According to the phylogenetic analysis results,3 of them showed99%identity to Halomonas lutescens Q1U.In addition,18 moderate halophiles had the 99%similarity with Halomonas stevensii S18214.Antagonistic analysis indicated that there was antagonistic relationship among 21 isolates.It is likely that there are some substances that can inhibit the pathogenic bacteria of the genus Halomonas.?2?Using the method of Clone Library Sequence?CLS?,as well as Mothur and Canoco software,the presence of AnAOB was detected in all 8 sediment samples,but with low and different diversity level.One known genus Candidatus Brocadia,four potential new genera and individual unknown sequences were found in the research region.RDA result demonstrated that concentration of Ca²⁺,Mg²⁺,NO₃^-,Cl^-,moisture content and salinity are the main influence factors to An AOB community diversity.?3?Using the method of q PCR,the abundance of An AOB was detected in all 8sediment samples.The lowest gene abundance was 2.97×10² copies/g,and the abundance of AnAOB in other 7 samples ranged from 1.51×10⁴².65×10⁵ copies/g.There were significant differences in the abundance of AnAOB among 8 sediment samples.Correlation analysis result indicated that the abundance is positively related to NH₄⁺,and negatively related to CO₃^2-,Na⁺as well as salinity.