The Pediococcus pentosaceus ACCEL bacteriocin was purified to electrophoretical homogeneity by cell adsorption-desorption and Superose 12 fast performance liquid chromatography (FPLC). The purified bacteriocin, with a molecular mass of 17.5 kDa and an N-terminal sequence of -KYYGNGVTXGKHSXXVDXG-, belongs to class IIa and is designated pediocin ACCEL. It was inactivated by various proteases and stable at pH 2.0-6.0 and <100 degrees C. More than 80% activity was left even after 15 min of heating at 121 degrees C and pH 2.0-4.0. Gram-positive food-borne pathogens were inhibited by this bacteriocin, but Gram-negative ones were not. According to the storage stability study, the purified pediocin was stable at pH <6.0 and low temperature. No significant change in bactericidal activity was observed after freeze-drying and subsequent 1-month storage at room temperature.