Characteristics of Arsenic Removal by Bacillus cereus Strain W2

Abstract

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.

Management of Natural Resources in a Changing Environment

“…After 48 h of incubation, cell mass removed ~55 % and ~56 % of total As when the medium was supplemented with As(III) and As(V) respectively. It seems KUMAs1 could remove As following the same mechanism as hypothesized by Miyatake and Hayashi ( 2009 ) in case of Bacillus megaterium strain UM-123, which could reduce As(V) under aerobic conditions and could also remove As by adsorption. Fig.…”

Copper-resistant, biofilm-forming bacteria for potential use in rehabilitation of copper-contaminated wastewater

“…The mechanism of biosorption by isolate T21 was not determined in this study. However, several reports indicate that B. subtilis sequesters heavy metal both extracellularly and intracellularly (Bai et al, 2014;Pan et al, 2007) while a strain of B. megaterium absorbs arsenic at its cell wall (Miyatake and Hayashi, 2009). Resistance to heavy metal is particularly necessary if the working microorganism is employed in a continuous bioreactor as used in this study.…”

Characteristics of Arsenic-methylation and Arsenic-removal by <i>Bordetella petrii</i> Strain KC42

“…However, as lyophilized cells of strain KC42 and strain UM-123 were unable to reduce As(V) to As(III), As(V) could not be removed from the aqueous solution. Strain KC42 was able to remove both As(III) and As(V) from the culture medium during culture, and the ratio removed was in the region of 70% in culture medium containing 0.5 mg As/L of As(III) 18 . When dried cells were used, strain KC42 was only able to remove As(III).…”