Verification of molecular mass and purity of compound B, as determined by MALDI-TOF MS analysis (main figure) and SDS-PAGE (figure insert). Lanes 1 and 2, molecular mass marker (in kilodaltons) and purified paenibacillin, stained with Coomassie blue G-250; lane 3, purified paenibacillin, overlaid with soft agar containing Lactobacillus plantarum ATCC 8014 after incubation.