Comprehensive Analysis of Soil Bacterial Diversity and Structure in Terra Nova Bay of Victoria Land

Abstract

For several decades, terrestrial environments in Antarctica had been believed as sterilized habitats without any life forms because of the extreme conditions. However, some studies nowadays have started to report the unexpected high diversity of bacteria and their community is complex in these harsh environments. In this study, we investigated the bacterial community and diversity in soil samples collected near the Terra Nova Bay of Victoria Land. Total 42 terrestrial soil samples with depths of 0-3 cm and 3-10 cm were collected in February of 2011. Measured values of soil parameters were pH ranged from 5.19 to 9.27 and water content ranged from 1.3% to 19.3%. By the 16S rRNA genes amplicon sequencing using pyrosequencing method, 67,007 sequence reads were obtained and 7,007 OTUs defined by 97% similarity cutoff were detected. Fifty onedivisions in phylum level were recognized, where the phyla of Actinobacteria (21.7%), Proteobacteria (13.7%), Acidobacteria (10.8%) and Cyanobacteria (10.7%) were dominant. Bacterial community structures were corresponded to the habitat locality. Interestingly, diverse phylotypes of Cyanobacteria with 190 OTUs were detected. Furthermore, the most dominant OTUs were assigned as Nostoc calcicola with 1,341 sequence reads and Microcoleus vaginatus with 1,005 sequence reads, which belonged to the phylum Cyanobacteria. These findings can provide new insights regarding the cyanobacterial community structure and their ecological roles in this ecosystem.