Characterization of microcystin-LR removal process in the presence of probiotic bacteria

► Identification of probiotic bacterial removal mechanisms of microcystin-LR - hypothesis of enzymatic degradation. ► No activity against microcystin-LR present in cytosolic fraction of probiotic bacteria. ► Extracellularly located cell-envelope proteinases involved in decomposition of microcystin-LR. ► Proteinase inhibitors limit rate of microcystin removal. ► Glucose dependent correlation between proteolytic activity and microcystin removal.