Diversity of mercury resistance determinants among Bacillus strains isolated from sediment of Minamata Bay.

Thirty mercury-resistant (Hg R) Bacillus strains were isolated from mercury-polluted sediment of Minamata Bay, Japan. Mercury resistance phenotypes were classified into broad-spectrum (resistant to inorganic Hg(2+) and organomercurials) and narrow-spectrum (resistant to inorganic Hg(2+) and sensitive to organomercurials) groups. Polymerase chain reaction (PCR) product sizes and the restriction nuclease site maps of mer operon regions from all broad-spectrum Hg R Bacillus were identical to that of Bacillus megaterium MB1.