Functional diversity of archaea in Brazilian Pantanal soda lakes and their role in nutrient cycling

Abstract

The Pantanal is the largest tropical wetland in the world and acts as an important reservoir of biodiversity, as well as performing essential functions in water retention and the dynamics of biogeochemical cycles. The soda lakes of this region are rare ecosystems, considered extreme environments due to severe abiotic conditions. Information related to the structure and functioning of microbial communities in these lakes are still incipient. Several groups of the Archaea domain are known for their ability to colonize extreme environments and to perform crucial functions in these ecosystems, but there are still no detailed studies on the diversity and functional potential of these microorganisms in Pantanal soda lakes. This work proposes to investigate the Archaea communities in these environments and their role in nutrients cycling, especially carbon (C) and nitrogen (N). For this, we will try to understand the ecological interactions between the microorganisms related to these cycles, from taxonomic and functional approaches. To understand the dynamics of these communities, phytoplankton and sediment samples will be evaluated in dry and rainy times through a comparative metagenomic analysis. The archaeal communities in adjacent soils to the lakes will also be explored, in order to evaluate possible influences on the microbial composition of the soda lakes. Finally, the enrichment technique will be used to isolate ammonia oxidizing archaea cultures and recover partial and/or complete microbial genomes, allowing the discovery of new taxa involved on N cycle. The results obtained in this research and other related projects will lead us to a general understanding of these poorly explored ecosystems, providing information that will contribute to the development of public policies aiming sustainable management of the Pantanal. (AU)