Isolation and characterization of a radiation-resistant bacterium from Taklamakan Desert showing potent ability to accumulate Lead (II) and considerable potential for bioremediation of radioactive wastes.

Abstract

Radioactive wastes always contain radioactive substances and a lot of Pb compound and other heavy metals, which severely contaminate soils and groundwater. Thus, search for radiation-resistant microorganisms that are capable of sequestering Pb contaminants from the contaminated sites is urgently needed. However, very few such microorganisms have been found so far. In the present study, we discovered a novel Gram-negative bacterium from the arid Taklamakan desert, which can strongly resist both radiation and Pb(2+). Phylogenetic and phenotypic analysis indicated that this bacterial strain is closely affiliated with Microvirga aerilata, and was thus referred to as Microvirga aerilata LM (=CCTCC AB 208311). We found that M. aerilata LM can effectively accumulate Pb and form intracellular precipitations. It also keeps similar ability to remove Pb(2+) under radioactive stress. Our data suggest that M. aerilata LM may offer an effective and eco-friendly in situ approach to remove soluble Pb contaminants from radioactive wastes.