Metagenomic analysis of microbial biodiversity of of Horseshoe island, Antarctic

The Antarctic continent is an extreme habitat that stands out with its arid climate, high altitude, very windy structure and low temperature values. The adaptation of microorganisms to polar conditions requires metabolic and cellular adaptation mechanisms especially in the field of biotechnology, together with their secondary metabolites, microorganisms with these adaptation mechanisms hold important place. In this study, it has been aimed to the microbial diversity of Antarctic Horseshoe island to the literature by metagenomic analysis of water, sediment and soil samples taken from this region. DNA was isolated from environmental samples and sequenced in Illumina NovaSeq 6000 after amplification of V3-V4 regions of 16S rRNA gene. The obtained sequence data were analyzed in the QIIME 2 program and divided into taxonomic groups. According to taxonomic results of the water sample, it was determined that mostly present taxa at the phylum level are Pseudomonadota and Bacteriodota; at the class-level are Gammaproteobacteria, Bacteriodia and Alphaproteobacteria; at the family level are Pseudoalteromonadaceae, Flavobacteriaceae and Rhodobacterales; and at the genus level are Pseudoalteromonas, Polaribacter, Sulfitobacter and Psychrobacter. The results of analysis of the sediment sample showed presence of Bacteroidota, Pseudomonadota, Verrucomicrobiota and Actinobacteria at the phylum level; Bacteroidia, Gammaproteobacteria and Verrucomicrobiae at the class level; Flavobacteriaceae, Rubritaleaceae and Comamonadaceae at the family level; and Ilumatobacter, Flavobacterium and Maribacter at the genus level. Analysis in the soil sample demonstrated that presence of Bacillota, Bacteriodota and Pseudomonadota at the phylum level; Bacteroidia, Bacili and Clostridia at class level; Chitinophagaceae, Bacteroidaceae and Lachnospiraceae at the family level; and Bacteroides, Lactobacillus and Prevotella at the genus level. The highest rate of alpha diversity was observed in the soil sample, while the lowest amount was determined in the water sample. The similarity of microorganism diversity among the samples was calculated as beta diversity and no significant similarity was found between each other. With this study, the microbial biodiversity of marine water, sediment and soil samples, which were collected from the Antarctic Horseshoe Island, were metagenomically revealed for the first time.