Characteristics of Arsenic Removal by Bacillus cereus Strain W2

抄録

Arsenic removal from contaminated groundwater using microorganisms is a desirable alternative to conventional methods. In this study, Bacillus cereus strain W2, which was isolated from soil in Miyazaki Prefecture, Japan, was examined for its potential to remove arsenic. Strain W2 was capable of removing arsenic from culture medium supplemented with either As(III) or As(V). When grown in medium containing 50.0 mg As (III)/l, strain W2 removed 1.870 mg As per gram of dry cell weight in 12 h. In experiments of arsenic adsorption by dried cells of strain W2, the ratio of As(III) adsorption by strain W2 ranged from 97.3 to 99.1% in solutions containing up to 1.0 mg As/l. Arsenic concentrations in solution decreased to 0.01 mg As/l or lower with initial concentrations of As(III) up to 0.5 mg As/l. The arsenic-removing capacity of strain W2 is higher than marine bacteria and genetically-modified Escherichia coli reported to date. These promising results indicate that strain W2 can be utilized for the bioremediation of arsenic-contaminated water.