Predictive prokaryotic functional metagenomics applied on an acid mine drainage affected environment

Abstract

In San Luis, Argentina, the acid mine drainage of an abandoned gold mine is released into LaCarolina stream. In previous studies, we determined that physicochemical parameters and botheukaryotic and prokaryotic diversity are affected by the presence of this mine in the study area. Likewise, we stablished specific relations between physicochemical parameters and microbialtaxonomic groups. The aim of the present study is to determine the prokaryotic functionaldifferences among samples according to the location in the study area. Twelve sediment samplesfrom the mine (7) and from the stream (5), before and after receiving the drainage, were selected to16S rRNA gene amplicon sequencing (MR DNA, TX, USA) on MiSeq platform (Illumina).PICRUSt software (www.picrust.github.io) was used to predict metagenome functional contentfrom 16S rRNA marker gene using KEGG Orthology (KO) database. Principal Component Analysiswas performed to visualize the distribution of functions and samples. This analysis showed thatfunctions such as environmental adaptation, biosynthesis of secondary metabolites, cellularprocesses and signaling, protein biosynthesis, energy metabolism, cell motility and geneticinformation processing were present to a greater extent in the samples taken from the south andlateral galleries of the mine, characterized by high heavy metal concentrations and low pH values.Cell communication function was associated to stream and main gallery samples, which werecharacterized by normal parameters. These results indicate that extreme conditions make tomicroorganisms to maintain an active metabolism, while cell communication is associated to normalconditions, where it is expected to find stable consortia.