Environmental Microanalysis & Monitoring Research Group directed by Dr. Lingxin Chen from YICCAS proposed two strategies to remove Hg(II) pollution from seawater matrix, which contribute to the development of promising technology to remove Hg(II) from the marine environment.

One strategy (Fig. A) is to transform Hg(II) to the relative inert Hg(0) by mer operon harbored in a marine isolate Pseudomonas putida strain SP1. P. putida strain SP1 was determined to completely transform 280 μM HgCl2. By absorbed the lower toxic Hg(0) onto the porous carrier materials, the Hg(II) in the aquatic environment could be removed via the biotransformation of P. putida strain SP1. And, the second strategy (Fig. B) is to adsorb Hg(II) by a genetically engineered surface displayed bacterium Top10/pBATGst, in which the DNA encoding a GST protein from Proteus mirabilis was fused with the DNA encoding Pfa1-based auto surface display system pBAT. Top10/pBATGst could constitutively express the chimeric GST and anchor it onto the cell surface subsequently. The recombinant GST on the cell surface still remained the conformation and function to adsorb Hg(II), Thus, the genetically engineered bacterium Top10/pBATGst could adsorb 97.5% and 96.5% of 100 nM Hg(II) from both lake water and seawater, respectively. And the quantitative recovery of Hg(II) bounded on the cell appeared to be simple, rapid with high efficiency.

The above research findings was published on the SCI journals of Applied Microbiology and Biotechnology (2012, 93:1305–1314) and Journal of Hazardous Materials (2013, 261: 646–652).