Release of the periplasmic penicillinases from Escherichia coli by toluene

Summary More than 80% of the chromosomally and R factor mediated, periplasmic penicillinases of Escherichia coli K-12, strains G11a1 and D1-R1, are released into the medium upon treatment with the membrane damaging agents toluene (50 l/ml) or polymyxin B (10 g/ml) within 10 min of incubation at 37°C. A concomitant release of protein (27 to 34%), but not of the cytoplasmic -galactosidase (<5%) occurs.