Distinct taxonomic and functional composition of soil microbiomes along the gradient forest-restinga-mangrove in southeastern Brazil

Soil microorganisms play crucial roles inecosystem functioning, and the central goal in microbialecology studies is to elucidate which factors shapecommunity structure. A better understanding of therelationship between microbial diversity, functionsand environmental parameters would increase ourability to set conservation priorities. Here, the bacterialand archaeal community structure in AtlanticForest, restinga and mangrove soils was described andcompared based on shotgun metagenomics. Wehypothesized that each distinct site would harbor adistinct taxonomic and functional soil community,which is influenced by environmental parameters. Ourdata showed that the microbiome is shaped by soilproperties, with pH, base saturation, boron and ironcontent significantly correlated to overall communitystructure. When data of specific phyla were correlatedto specific soil properties, we demonstrated thatparameters such as boron, copper, sulfur, potassiumand aluminum presented significant correlation withthe most number of bacterial groups. Mangrove soilwas the most distinct site and presented the highesttaxonomic and functional diversity in comparisonwith forest and restinga soils. From the total 34microbial phyla identified, 14 were overrepresented inmangrove soils, including several archaeal groups.Mangrove soils hosted a high abundance of sequencesrelated to replication, survival and adaptation; forestsoils included high numbers of sequences related tothe metabolism of nutrients and other composts; whilerestinga soils included abundant genes related to themetabolism of carbohydrates. Overall, our finds showthat the microbial community structure and functionalpotential were clearly different across the environmentalgradient, followed by functional adaptationand both were related to the soil properties