Genome-resolved metagenomics reveals novel archaeal and bacterial genomes from Amazonian forest and pasture soils

Abstract

Amazonian soil microbial communities are known to be affected by the forest-to-pasture conversion, but the identity and metabolic potential of most of their organisms remain poorly characterized. To contribute to the understanding of these com-munities, here we describe metagenome-assembled genomes (MAGs) recovered from 12 forest and pasture soil metagenomes of the Brazilian Eastern Amazon. We obtained 11 forest and 30 pasture MAGs (≥50% of completeness and ≤10 % of contamina-tion), distributed among two archaeal and 11 bacterial phyla. The taxonomic classification results suggest that most MAGs may represent potential novel microbial taxa. MAGs selected for further evaluation included members of Acidobacteriota, Actinobac-teriota, Desulfobacterota_B, Desulfobacterota_F, Dormibacterota, Eremiobacterota, Halobacteriota, Proteobacteria, and Thermopro-teota, thus revealing their roles in carbohydrate degradation and mercury detoxification as well as in the sulphur, nitrogen, and methane cycles. A methane-producing Archaea of the genus Methanosarcina was almost exclusively recovered from pasture soils, which can be linked to a sink-to-source shift after the forest-to-pasture conversion. The novel MAGs constitute an impor-tant resource to help us unravel the yet-unknown microbial diversity in Amazonian soils and its functional potential and, con-sequently, the responses of these microorganisms to land-use change.