Authors: Anne Fahy Ludovic Giloteaux Philippe Bertin Denis Le Paslier Claudine Médigue Jean Weissenbach Robert Duran Béatrice Lauga
Publish Date: 2015/01/16
Volume: 70, Issue: 1, Pages: 154-167
Abstract
To gain an indepth insight into the diversity and the distribution of genes under the particular evolutionary pressure of an arsenicrich acid mine drainage AMD the genes involved in bacterial arsenic detoxification arsB ACR3 and arsenite oxidation aioA were investigated in sediment from Carnoulès France in parallel to the diversity and global distribution of the metabolically active bacteria The metabolically active bacteria were affiliated mainly to AMD specialists ie organisms detected in or isolated from AMDs throughout the world They included mainly Acidobacteria and the nonaffiliated “Candidatus Fodinabacter communificans” as well as Thiomonas and Acidithiobacillus spp Actinobacteria and unclassified Gammaproteobacteria The distribution range of these organisms suggested that they show niche conservatism Sixteen types of deduced protein sequences of arsenite transporters 5 ArsB and 11 Acr3p were detected whereas a single type of arsenite oxidase AioA was found Our data suggested that at Carnoulès the aioA gene was more recent than those encoding arsenite transporters and subjected to a different molecular evolution In contrast to the 16S ribosomal RNA 16S rRNA genes associated with AMD environments worldwide the functional genes aioA ACR3 and to a lesser extent arsB were either novel or specific to Carnoulès raising the question as to whether these functional genes are specific to high concentrations of arsenic AMDspecific or sitespecificThe authors acknowledge financial support from the Aquitaine Regional Government Council France and the ANR RARE project no 07BLAN0108 LG was partly supported by a doctoral grant from the Ministère de l’Enseignement Supérieur et de la Recherche France
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