Characterization of Copper-Resistant Agrobacterium Isolated from Legume Nodule in Mining Tailings

A copper-resistant bacteria CCNWSX2332 was isolated from root nodules of Lespedeza cuneata growing in a gold mining tailing region in northwest of China. The specific growth rate of the strain was 0.62 μh⁻¹ in the presence of 2.0 mM Cu²⁺ in TY liquid media, and the maximum copper accumulation of whole cell reached 147.03 μM Cu²⁺ per gram (dry weight) after 4 h incubation. A partial sequence of the copper resistance gene copA was amplified from the strain, and the phylogenetic analysis based on 16S rDNA sequence showed that CCNWSX2332 belonged to Agrobacterium, and it had 100% similarity with Agrobacterium tumefaciens type strain IAM13129^T.