Question

Diversity surveys and evolutionary relationships of aoxb genes in aerobic arsenite-oxidizing bacteria

Answer 1

We then explored the genetic diversity of this gene in order :

(i) to identify conserved structural and functional domains

(ii) to compare AoxB and 16S rRNA phylogenies to evaluate whether phylogenetic information

(III)-oxidizing bacteria can be inferred from the aoxB gene

Answer 2

Explanation:

A new primer set was designed to specifically amplify ca. 1,100 bp of aoxB genes encoding the As(III) oxidase catalytic subunit from taxonomically diverse aerobic As(III)-oxidizing bacteria. Comparative analysis of AoxB protein sequences showed variable conservation levels and highlighted the conservation of essential amino acids and structural motifs. AoxB phylogeny of pure strains showed well-discriminated taxonomic groups and was similar to 16S rRNA phylogeny. Alphaproteobacteria-, Betaproteobacteria-, and Gammaproteobacteria-related sequences were retrieved from environmental surveys, demonstrating their prevalence in mesophilic As-contaminated soils. Our study underlines the usefulness of the aoxB gene as a functional marker of aerobic As(III) oxidizers.