부산대학교 도서관

The efficiency of microbial volatilization of mercury was examined using bacterial strains isolated from Chesapeake Bay, a major estuary of the eastern seaboard of the United States, and one strain isolated from the Cayman Trench, a deep ocean site. Volatilization of mercury was studied under both aerobic and anaerobic conditions. The mechanism of mercury volatilization was determined to be plasmid mediated in two of the strains tested, but appeared to be chromosomally mediated in one strain of Pseudomonas fluorescens. The percent of mercury volatilized under aerobic conditions from media containing 10 mg HgCl[SUB2]/liter ranged from 21.5-87.2% within 24 h. Incubation under anaerobic conditions resulted in 12.7-78.1% volatilization of the mercury. Mercuric reductases associated with the plasmids were shown to be responsible for volatilization of mercury. Aerobic volatilization of mercury was observed to be more efficient than anaerobic volatilization. Furthermore, methylation of mercury was found to be a phenomenon separate from volatilization, with only two of the bacterial strains proving capable of producing methylmercury under either aerobic or anaerobic conditions. It is concluded that bacteria can mobilize mercury in the marine environment and may be potential agents for recycling mercury from mercury-laden wastes. [ABSTRACT FROM AUTHOR]