Physiology and genetics of Rhodococcus aetherivorans BCP1 response to Arsenic

Arsenic ranks among the priority metals that are of public health significance. In the environment, the metalloid arsenic mainly exists under two forms: the arsenite [As(III)] and arsenate [As(V)]; the former being more toxic due to its high mobility and stability. Bacteria have developed multiple strategies for arsenic detoxification. Rhodococcus aetherivorans BCP1 is able to cometabolize chlorinated compounds, mineralize a wide range of hydrocarbons1, resist different stress conditions2 and convert tellurite and selenite into less toxic forms3, making this strain an ideal candidate for microbial biotechnology applications. In this study, we assessed the ability of BCP1 to tolerate high concentrations of As(V) during its growth under aerobic conditions. Furthermore, different aspects regarding the arsenic homeostasis and the response of BCP1 to As(V) were investigated: (i) the different capability to convert As(V) into As(III) depending on the initial concentration of arsenate; (ii) the arsenic biosorption; (iii) the effect of arsenic on polyphosphate granule formation and (iv) the genetic/genomic aspects involved in arsenic detoxification. Finally, the detection of electrondense nanoparticles after the incubation with As(V) suggested the ability of BCP1 strain to generate As-based nanostructures.