Characterization of cesium uptake mediated by a potassium transport system of bacteria in a soil conditioner

Abstract

We found that bacteria in a commercial soil conditioner sold in Ishinomaki, Miyagi, exhibited concentrative and saturable cesium ion (Cs +) uptake in the natural range of pH and temperature. The concentration of intracellular Cs + could be condensed at least a few times higher compared with the outside medium of the cells. This uptake appeared to be mediated by a K + transport system, since Cs + uptake was dose-dependently inhibited by potassium ion (K +). Eadie-Hofstee plot analysis indicated that the Cs + uptake involved a single saturable process. The maximum uptake amount (J max) was the same in the presence and absence of K +, suggesting that Cs + and K + uptakes were competitive with respect to each other. These bacteria might be useful for bioremediation of cesium-contaminated soil. © 2014 The Pharmaceutical Society of Japan.