[Research on the bioaccesibility of HgS by Shewanella oneidensis MR-1]

The biological dissolution and methylation of solid HgS by Shewanella oneidensis MR-1 and influenced factors under laboratory conditions were studied. Results showed that S. oneidensis MR-1 could grow well at the low concentration of Na2S, but its growth was inhibited at the high concentration of Na2S, which mainly happened in the prolonged lag phase. Iron reducing bacteria S. oneidensis MR-1 could access the solid mercuric sulfide, and rapidly promote the biological dissolution and methylation of HgS. In the appropriate range of sulfide to S. oneidensis MR-1, the biological solubility of HgS was enhanced with the increasing concentration of Na2S, but the methylation just promoted at the low Na2S concentration, and it would be inhibited when the concentration is high. In addition, weakly acidic environment was more beneficial to biological dissolution and methylation of HgS than acidic, neutral or alkaline conditions by S. oneidensis MR-1.