Optimization of conditions for removal of 137Cs by Rhodococcus erythropolis CS98 immobilized in agarose hydrogel

Abstract

Several microorganisms reportedly accumulate cesium. Among these microorganisms, Rhodococcus erythropolis CS98 shows the highest accumulation. We previously showed that agarose gel was more suitable for immobilization of the CS98 strain than calcium alginate gel and poly(vinyl alcohol) gel. In this study, we optimized the conditions for removal of 137Cs from artificial contaminated water by the CS98 strain immobilized in agarose gel. The optimum ammonium acetate concentration, pH, temperature of the contaminated water, and cell density in the agarose gel were 5 mM, 8.5, 20-40 ｰC, and 3.6 ﾗ 109 cells per 2 mL of gel, respectively.