Characterization of the metabolically modified heavy metal-resistant Cupriavidus metallidurans strain MSR33 generated for mercury bioremediation

Environmental decontamination of polluted sites is one of the main challenges for sustainable development. Bioremediation is an attractive technology for the clean-up of polluted waters and soils [1]-[6]. Mercury is one of the most toxic elements in the environment [7], [8]. Metal mining, fossil combustion and the chloralkali and acetaldehyde industries have raised mercury levels in water bodies and soils. Mercury enters from industrial sources mainly as Hg2+ into the environment [9]-[11]. Physicochemical and biological processes have been applied for mercury removal from contaminated environments. Physicochemical processes for heavy metal removal such as ion exchange and precipitation treatment procedures result in large volumes of mercury-contaminated sludge and are of high cost [12]-[13]. As an alternative to physicochemical processes, bacteria have been applied for the remediation of mercury pollution [1], [3], [10], [14]. The biological processes for mercury removal are of low cost, simple and environmentally friendly [10]. Mercury-polluted sites are often contaminated with other heavy metals [15]. Therefore, bacteria with resistance to several heavy metals may be useful for remediation.