First approach to the microbial diversity in the James Ross Archipelago, Antarctica

GUILLERMO FERNANDEZ; ELIANA SOTO RUEDA; LAURA BORGNINO; KARINA LECOMTE; CECILIA MLEWSKI

Congreso; Congreso ISME Latinoamérica 2019; 2019

The Antarctic benthic areas that receive sufficient solar radiation are covered by microbialmats. For thousands of years these microorganisms were challenged to extremeconditions, such as low temperatures, freezing-thawing periods, high UV-irradiation,elevated salinity and low nutrient concentrations. In this context, many of them developadaptations and in consequence potential microorganisms belonging to endogenous taxa and organisms not identified yet, can still be discovered.The terrestrial vegetation in the James Ross Archipelago is limited to lichens andbryophytes, whereas microbial benthic mats are composed of algae and cyanobacteria.However, no studies of the microbial diversity -using high-throughput sequencing technologies as well as the analysis of mineral precipitation and fossil mats record in theselakes- have been conducted. For these reason, in a first step, we focused on the study of the bacterial diversity of three microbial mats corresponding to two lakes in James RossIsland and one in Vega Island. We used 16S rDNA amplicon secuencing by Illumina Miseq analysis. Preliminary results show that Proteobacteria was the most abundant phylum, inboth island but differences were found in Bacteroidetes, Cyanobacteria and Actinobacteria phyla. These differences in abundance could be related to the physicochemical characteristic of the lakes like pH (8.5 to 10.2), the concentration of organic matter vs inorganic carbon content and trace metal concentration.This multidisciplinary study will contributes to a better understanding of Antarctic lake systems and can be used as a baseline dataset for further studies investigating the impact of climate changes in these pristine ecosystems.