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

FERNÁNDEZ G; SOTO RUEDA E; BORGNINO BIANCHI, LC; LECOMTE K.L.; MLEWSKI EC

Valparaiso

Congreso; I ISME Latin America; 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 taxaand 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 sequencingtechnologies 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 ofthe 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 Miseqanalysis. Preliminary results show that Proteobacteria was the most abundant phylum, inboth island but differences were found in Bacteroidetes, Cyanobacteria and Actinobacteriaphyla. These differences in abundance could be related to the physicochemicalcharacteristic of the lakes like pH (8.5 to 10.2), the concentration of organic matter vsinorganic carbon content and trace metal concentration.This multidisciplinary study will contributes to a better understanding of Antarctic lakesystems and can be used as a baseline dataset for further studies investigating the impactof climate changes in these pristine ecosystems.