【摘要】 为了解新疆乌恰泉华地震前后泉水细菌群落的变化,采用微生物纯培养方法结合16S rRNA基因序列系统发育分析法对地震前后泉水样品进行研究。结果表明,地震前和地震后可培养菌落的数目、菌群结构和优势菌都存在差异。地震前,25株菌分属于11个科12个属17个种,多数菌落归属于变形菌门γ亚群(Gammaproteobacteria)(82.63%),其中优势菌株为窄食单胞菌属某种。RB25(Stenotrophomonassp.RB25)(56.86%)和不动杆菌属某种.RB11(Acinetobactersp.RB11)(24.31%);地震后,27株菌分属于14个科17个属21个种,总细菌数量减少,但生物多样性提高,变形菌门α亚群(Alphaproteobacteria)(49.64%)上升为优势类群,优势菌株为根瘤菌属某种.RA42(Rhizobiumsp.RA42)(28.21%)。该研究为泉水微生物的映震研究积累了资料。更多还原

【Abstract】 Spring water,which is one of the most active parts of the earth′s crust media,can actually and sensitively reflect the stress in the crust.Wuqia Sinter(40°25′07″-40°25′39″ N,75°09′37″-75°09′58″ E) lies in the linkage of the Tianshan Mountains and Kunlun Mountains in Wuqia County of Xinjiang,which is an earthquake-prone area.Wuqia Sinter is a very infrequent karst landform that is closely related to spring water.The sampling site(40°25′30″ N,75°09′58″ E) is the largest spring of Wuqia Sinter,approximately 146 km from the epicenter.In this study,we examined the spring bacterial community composition from Wuqia Sinter during the pre- and post-earthquake stages by using traditional microbiological culturability methods followed by 16S rRNA phylogenetic classification.Our objective was to preliminarily investigate the variation of a spring bacterial community from Wuqia Sinter under earthquake action.The results revealed that the culturable community number,community composition and the dominant microbes differed during these two stages.On R2A media,the culturable bacteria numbers corresponded for the pre- and post-earthquake stages were 13.15×102 CFU/mL and 2.00×102 CFU/mL,respectively.And on NA media,the culturable bacteria numbers corresponded for the pre- and post-earthquake stages were 7.88×102 CFU/mL and 0.87×102 CFU/mL,respectively.The culturable bacteria counts decreased significantly(P < 0.01) after the earthquake.R2A agar,a low-nutrient medium,is more suitable to culture the microbial in an oligotrophic water environment.Overall,52 CFU(25 from the pre-earthquake spring water and 27 from the post-earthquake spring water) were selected from the terminal positive dilution steps for analysis.Phylogenetic analysis of the bacterial 16S rRNA gene sequences showed that all isolates fell into one of the following six bacterial lineages: Actinobacteria,Alphaproteobacteria,Bacteroidetes,Deinococcus-Thermus,Firmicutes and Gammaproteobacteria.The following genera were detected in both the pre- and post-earthquake samples: Acinetobacter,Bacillus,Bosea,Brevundimonas,Deinococcus,Micrococcus,Rhizobium and Roseomonas.Additionally,the genera Lysobacter,Nocardiopsis,Stenotrophomonas and Streptomyces were no longer present after the earthquake,while Aeromonas,Arthrobacter,Flavobacterium,Kocuria,Mycetocola,Pedobacter,Planomicrobium,Rothia and Staphylococcus only appeared during the post-earthquake stage.Some strains had higher adaptability,which could exist in both the pre- and post-earthquake stages,including Rhizobium sp.RA42,Brevundimonas sp.RB44,Brevundimonas sp.RA61,Bosea sp.RA62,Roseomonas sp.RB63,Acinetobacter sp.NB115,Micrococcus sp.NB52,Deinococcus sp.RA45 and Bacillus sp.RA23.In the pre-earthquake stage,25 pre-earthquake colonies grouped into 17 phylotypes,and the majority of isolates were affiliated with the Gammaproteobacteria(82.63%),including two numerically dominant organisms,Stenotrophomonas sp.RB25(56.86%) and Acinetobacter sp.RB11(24.31%),which disappeared after the earthquake.While in the post-earthquake stage,27 post-earthquake colonies formed 21 phylotypes,the abundance of total bacterial decreased,but bacterial diversity was higher.The predominant groups among the post-earthquake isolates were Alphaproteobacteria(49.64%),including the numerically dominant Rhizobium sp.RA42(28.21%).Strains Stenotrophomonas sp.RB25,Acinetobacter sp.RB11 and Rhizobium sp.RA42 are likely to be as indicator strains during the pre- and post-earthquake period in Wuqia of Xinjiang,China.The results obtained in this study should provide a preliminary assessment of the responses of the spring microbial population in Wuqia Sinter to earthquakes,which will accumulate data for reflecting earthquake analysis of spring microorganisms.更多还原