Three‐year survey of sulfate‐reducing bacteria community structure in C arnoulès acid mine drainage ( F rance), highly contaminated by arsenic

A 3‐year survey on sulfate‐reducing bacteria ( SRB ) was conducted in the waters of the arsenic‐rich acid mine drainage ( AMD ) located at C arnoulès ( F rance) to determine the influence of environmental parameters on their community structure. The source ( S 5 station) exhibited most extreme conditions with p H lowering to ~1.2; iron, sulfate, and arsenic concentrations reaching 6843, 29 593, and 638 mg L −1 , respectively. The conditions were less extreme at the downstream stations S 1 (p H ~3.7; iron, sulfate, and arsenic concentrations of 1114, 4207, and 167 mg L −1 , respectively) and COWG (p H ~3.4; iron, sulfate, and arsenic concentrations of 854, 3134, and 110 mg L −1 , respectively). SRB community structures were characterized by terminal restriction fragment length polymorphism and library analyses based on dsrAB genes. The predominant dsrAB sequences detected were most similar to the family D esulfobulbaceae . Additionally, certain phylotypes could be related to spatio‐temporal fluctuations of p H , iron, and arsenic species. For example, D esulfohalobiaceae ‐related sequences were detected at the most acidic sample (p H 1.4) with high iron and arsenic concentrations (6379 and 524 mg L −1 , respectively). New dsrAB sequences, with no isolated representatives, were found exclusively in COWG . This study gives new insights on SRB community dynamics in AMD systems.