Culture-dependent and -independent molecular characterization of microbial communities sampled from beneath a high Arctic glacier (John Evans Glacier, Ellesmere Island, Canada)

High numbers of viable bacteria have been detected beneath John Evans Glacier (JEG), an environment that was once thought devoid of life. This study used culture-dependent and culture-independent amplified ribosomosal DNA restriction analysis (ARDRA) of 16S ribosomal RNA genes to characterize subglacial and proglacial microbial communities at JEG. ARDRA analysis revealed a high diversity of bacteria beneath JEG comprising members of the α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Cytophaga-Flavobacteria-Bacteriodes, Actinobacteria and Firmicutes divisions. Many sequenced representatives from culture-dependent analysis were closely related to sequenced representatives from culture-independent analysis, showing reasonable correlation between the two methods. Theoretical 5' terminal fragments of 16S rRNA genes generated from sequenced representatives correlated with 11 terminal fragments detected through terminal restriction fragment length polymorphism analysis of JEG samples from a previous study. These results show that a combination of different characterization techniques is necessary to gain a more comprehensive understanding of environmental samples.