Comparison of Bacterial Communities from the Surface and Adjacent Bottom Layers Water of Billings Reservoir

Abstract Here, we describe the microbial diversity and physicochemical properties in freshwater samples from the surface and bottom layer of Billings reservoir in São Paulo state, Brazil. Twenty-two matched samples were characterized using the 16S rRNA gene Illumina MiSeq platform. Taxonomical composition revealed an abundance of Cyanobacteria phyla, followed by Proteobacteria, with 1903 and 2689 known bacterial genera in the surface and deep-water layers, respectively. Shannon diversity index ranging from 2.3 - 5.39 and 4.04 - 6.86 in the surface and bottom layer, respectively. Among the 120 pathogenic genera identified, Flavobacterium was the most predominant genus. Temperature and phosphorus concentration were the most influential factors in shaping the microbial communities of both layers. Predictive functional analysis suggests that the reservoir is enriched in motility genes involved in the flagellar assembly. The overall results present new information on the significantly altered diversity composition of the bacterial community detected in Billings freshwater reservoir.