Adaptation in Toxic Environments: Arsenic Genomic Islands in the Bacterial Genus Thiomonas

PLoS One. 2015 Sep 30;10(9):e0139011. doi: 10.1371/journal.pone.0139011. eCollection 2015.

Abstract

Acid mine drainage (AMD) is a highly toxic environment for most living organisms due to the presence of many lethal elements including arsenic (As). Thiomonas (Tm.) bacteria are found ubiquitously in AMD and can withstand these extreme conditions, in part because they are able to oxidize arsenite. In order to further improve our knowledge concerning the adaptive capacities of these bacteria, we sequenced and assembled the genome of six isolates derived from the Carnoulès AMD, and compared them to the genomes of Tm. arsenitoxydans 3As (isolated from the same site) and Tm. intermedia K12 (isolated from a sewage pipe). A detailed analysis of the Tm. sp. CB2 genome revealed various rearrangements had occurred in comparison to what was observed in 3As and K12 and over 20 genomic islands (GEIs) were found in each of these three genomes. We performed a detailed comparison of the two arsenic-related islands found in CB2, carrying the genes required for arsenite oxidation and As resistance, with those found in K12, 3As, and five other Thiomonas strains also isolated from Carnoulès (CB1, CB3, CB6, ACO3 and ACO7). Our results suggest that these arsenic-related islands have evolved differentially in these closely related Thiomonas strains, leading to divergent capacities to survive in As rich environments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arsenic*
  • Burkholderiaceae / genetics*
  • Burkholderiaceae / isolation & purification
  • Genome, Bacterial*
  • Water Microbiology*

Substances

  • Arsenic

Grant support

This work was supported by the Université de Strasbourg (UdS), the Centre National de la Recherche Scientifique (CNRS) and the Region Alsace to JF. This study was financed by the EC2CO program (INEE, CNRS), the RARE (ANR 07-BLANC-0118) and the THIOFILM (ANR-12-ADAP-0013) projects. JF and KCF were supported by the Agence Nationale de la Recherche, ANR THIOFILM (ANR-12-ADAP-0013). FA-P was supported by the CNRS (« mise en délégation pour activité de recherche au CNRS »). CB-A is member of the Institut Universitaire de France and was supported by a Projet d’Avenir (Ancestrome, ANR-10-BINF-01-01) grant. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.