Organic acids production as a possible mechanism of uptake of Cs by mushrooms

Guido-Garcia, F.; Sakamoto, Fuminori  ; Kozai, Naofumi   ; Grambow, B.

Cs was released from FNPP in 2011 and is one of the main concerns due to its half-life and prevalence in forests. Here, Cs can be taken and accumulated by different organisms, e.g. mushrooms. This can result in mobilization through the environment. Elucidating the mechanisms by which cesium is taken from soil by mushrooms is key to understand its environmental behavior. In soil, Cs can be tightly fixed to clay minerals thus its bioavailability is poor. Organic acids and siderophores produced by mushrooms may remove Cs from mineral surfaces making it bioavailable. To assess this, different strains of fungi were chosen from a ~1000 collection that has been previously tested for Cs accumulation capacity. Organic acids were analyzed by GC-MS and HPLC-ICP-MS from different strains with different accumulating capacities. These were then tested in cesium desorption experiments using key minerals, and compared to a commercial siderophore.