Fifteen millilitres of the overnight culture was seeded into 1.5 l LB broth and grown in the presence of both anti- biotics. When the culture reached an OD600 of 0.6, 0.2 mM IPTG was added and the induction continued at 37 °C for 3.5 h. Cells were harvested at 5,000g for 15 min...