부산대학교 도서관

The Lonar crater is an unusually well-preserved meteorite impact structure that is located in one of the largest volcanic provinces on Earth (i.e., the Deccan Traps in India). The diversity of endoliths in Lonar crater basalts or Deccan flood basalts is not known. Here, the phylogenetic diversity of endolithicBacteriaandArchaeainhabiting basalts retrieved from four discrete sampling sites on the Lonar crater walls and the lake-bed was assessed using culture-independent molecular methods. Taxonomic classification of 16S rRNA gene sequences from all four basalt samples revealed similarities as well as dissimilarities in the presence or absence of several prokaryotic taxa. Cluster analysis of Denaturing gradient gel electrophoresis fingerprints and UniFrac analysis of clone library sequences suggested substantial variations in bacterial and archaeal diversity between crater-wall and lake-bed sites. Although sequences affiliated to the bacterial phylaActinobacteria,AcidobacteriaandChloroflexiwere relatively more abundant in crater-wall basalts than in lake-bed basalts; the reverse was observed for sequences related toProteobacteria,Firmicutes,CyanobacteriaandBacteroidetes.Archaeain crater-wall and lake-bed basalt libraries were almost completely represented byThaumarchaeotaandEuryarchaeota, respectively. Diversity indices and richness estimates suggested the diversity of endolithicBacteriato be higher than that ofArchaeain the Lonar crater basalts. A substantial number of clone library sequences did not affiliate with extantBacteriaandArchaea. The detection of several putative lineages associated with C, N and S cycling suggests that the Lonar crater basalts are colonized by metabolically diverse prokaryotic communities involved in biogeochemical cycling of major elements. [ABSTRACT FROM AUTHOR]