Multi-time Scale Variation Characteristics Of Spring Microbial Community In Urumqi No.10 Spring And Its Response To Earthquake

The earthquake monitoring and prediction is one of the unsolved scientific problems in the present world.Microorganisms have the property of environmental anticipation,which can rapidly perceive and adapt environmental change during evolution.It is worth to deeply study whether monitoring groundwater microorganisms can become a new tool to monitor crustal activity.Surrounding the scientific problem on "Abnormal reactions of spring microbial community and metabolism before and after the earthquake",this paper will continuously investigate the spring microbial communities in Urumqi No.10 Spring.Our objectives are to reveal the stability and change of the sensitive community structures and activities,and to extract qualitative and quantitative information of microbial abnormal reaction,and last to explore the relationship between these changes and the earthquake.Firstly,the seasonal and annual changes of twelve hydrogeochemical characteristics of in Urumqi No.10 Spring were studied and results showed that some abnormal values were recorded and these changes may be related to the happenings of earthquake.Next,the bacterial population abundance in the spring water were compared on the scale of a year,different seasons and different years.Results from these comparisons showed that no significant changes were found within a year,but significant changes were found in different seasons within a year with the tendency of summer>autumn>spring>winter;and significant changes were also observed in different years.The analyses of bacterial population structure in the spring water displayed that the bacterial populations represented by T-RFs sizes of 91bp,129bp,305bp,165bp,454bp were the most predominant populations in the ecological system of Urumqi No.10 Spring,and of them,the two populations represented by T-RFs sizes of 129bp and 305bp were the relatively stable indigenous bacteria.By combining the hydrogeochemical characteristics and the change of bacterial abundance,we found the concentration or content of F-,Rn and CH4 were the mainly influence factors for the change of bacterial abundance in spring water in the summer,autumn and winter.The community structure,activity and metabolic function of spring microbial were also analyzed based on the hydrogeochemical parameters and four typical earthquake cases during our detection period by using molecular method,Terminal Restriction Fragment Length Polymorphism(T-RFLP),and phenotype analysis method,BIOLOG-ECO.The results showed that the microbial communities represented by T-RFs sizes of 91bp,129bp,305bp,454bp were the common communities in the four earthquake cases,which may be earthquake-sensitive bacteria because of abnormal fluctuation during the pre-and post-earthquake.And these bacteria could be used to detect the occurrence of earthquake.RDA analysis indicated that Gas,EC were the key influencing factors affecting the change of bacterial community.Results from the BIOLOG-ECO showed that the microorganism in the spring could utilize glycidyl-L-glutamic acid as the main carbon source,and D-galactose acid-y-lactone and galacturonic acid were the mainly sensitive carbon sources affecting the different carbon metabolism.Overall,the results obtained in this study will provide a new monitoring index and idea for the earthquake monitoring and prediction,then provide complement and reference for improving the accuracy of earthquake prediction,and lay a basis for trying to monitor crust activities with microbial community.