Authors: Pieter Monsieurs Hugo Moors Rob Van Houdt Paul J Janssen Ann Janssen Ilse Coninx Max Mergeay Natalie Leys
Publish Date: 2011/06/25
Volume: 24, Issue: 6, Pages: 1133-1151
Abstract
The soil bacterium Cupriavidus metallidurans CH34 contains a high number of heavy metal resistance genes making it an interesting model organism to study microbial responses to heavy metals In this study the transcriptional response of strain CH34 was measured when challenged to sublethal concentrations of various essential or toxic metals Based on the global transcriptional responses for each challenge and the overlap in upregulated genes between different metal responses the sixteen metals were clustered in three groups In addition the transcriptional response of already known metal resistance genes was assessed and new metal response gene clusters were identified The majority of the studied metal response loci showed similar expression profiles when cells were exposed to different metals suggesting complex interplay at transcriptional level between the different metal responses The pronounced redundancy of these metal resistant regions—as illustrated by the large number of paralogous genes—combined with the phylogenetic distribution of these metal response regions within either evolutionary related or other metal resistant bacteria provides important insights on the recent evolutionary forces shaping this naturally soildwelling bacterium into a highly metalresistant strain well adapted to harsh and anthropogenic environments
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