Microbial Community of the Arctic Soil from the Glacier Foreland of Midtre Lovenbreen in Svalbard by Metagenome Analysis

Abstract

Recent successions of soil microorganisms and vegetation have occurred in the glacier foreland because of glacier thawing. In this study, whole microbial communities including bacteria, archaea and eukaryotes from the glacier foreland of Midtre Lovenbreen in Svalbard were analyzed by metagenome-sequencing using the Ion Torrent Personal Genome Machine (PGM) platform. Soil samples were collected from two research sites (ML4 and ML7) with different exposure time from the ice. A total of 2,798,108 and 1,691,859 reads were utilized for microbial community analysis based on the metagenomic sequences of ML4 and ML7, respectively. The relative abundance of microbial communities at the domain level showed a high proportion of bacteria (about 86-87%), whereas archaeal and eukaryotic communities were poorly represented by less than 1%. The remaining 12% of sequences were found to be unclassified. Predominant bacterial groups included Proteobacteria (40.3% for ML4 and 43.3% for ML7) and Actinobacteria (22.9% and 24.9%). Major groups of Archaea included Euryarchaeota (84.4% and 81.1%), followed by Crenarchaeota (10.6% and 13.1%). In the case of eukaryotes, both ML4 and ML7 samples showed Ascomycota (33.8% and 45.0%) as the major group. These findings suggest that metagenome analysis using the Ion Torrent PGM platform could be suitably applied to analyze whole microbial community structures, providing a basis for assessing the relative importance of predominant groups on bacterial, archaeal and eukaryotic microbial communities in the Arctic glacier foreland of Midtre Lovenbreen with high resolution.