SDS-polyacrylamide gel electrophoresis and fluorography of total cell extracts radiolabeled with [3H]palmitic acid. The loaded samples correspond to 0.1 U (0.1 U: quantity of cells in 100 μl of L. lactis culture at an optical density at 600 nm of 1). (A) Overproduction of PmpA in L. lactis. Lanes 1 and 2, NZ9000 (control strain without pJIM2080) noninduced and induced by nisin, respectively; lanes 3 and 4, MG-Pnis::pmpA (NZ9000 with pJIM2080) noninduced and induced by nisin, respectively. (B) Visualization of pmpA mutation. Lane 1, MG1363; lane 2, MG-pmpA.