Radionuclide remediation is becoming an increasingly serious environmental problem, posing threat to biotic life. Biosorption is a technology for the treatment of wastewater containing metal ions. In this work, the biosorption of strontium ions (Sr2+) to baker's yeast and the effect of gamma-ray radiation on the biosorption process were investigated at different experimental conditions. The experimental results fitted well to the Langmuir and Freundlich model isotherms before and after the gamma-ray radiation (r(2) > 0.985), and the maximum biosorption capacity values were q(max) > 33.0 mg g(-1) at 30 degrees C. Negative values of Delta G(0) and positive values of Delta H-0 were observed indicating, the spontaneous and endothermic nature of Sr2+ biosorption on baker's yeast, respectively. The biosorption kinetics followed a pseudo-second-order equation at different experimental temperatures (r(2) > 0.999), the calculate results of the strontium sorption capacity at equilibrium (q(e,cal)) increased about 0.4-1.0 mg g(-1), after gamma-ray irradiated. The activation energy of baker's yeast biosorption to Sr2+ decreased 0.79 kJ mol(-1) after gamma-ray radiation. The gamma-ray radiation affects the amide bands of proteins and leads to a decrease of the isoelectric point from pH of 2.55 to 2.25 and an increase in the electronegativity of the cells wall. In summary, an appropriate gamma-ray radiation condition not only has no negative effects, but also can enhance its biosorption capacity slightly of Sr2+ to baker's yeast. (C) 2014 Elsevier B.V. All rights reserved.