Cylindrospermopsin is an alkaloid toxin, produced by different cyanobacteria. It is considered hepatotoxic, cytotoxic and neurotoxic and has been detected all over the world. The biodegradation of these molecules could be a feasible and economic way to eradicate them. The ability of iron/manganese bacteria to degrade some recalcitrant compounds has been reported. For that reason the aim of the study is to evaluate the toxin´s degradation potential and to determine the expression level of genes related with some xenobiotic degradation pathways.