Plasmids were electroporated into strain RL08 and selected on Luria–Bertani (LB) agar (Becton Dickinson, Cockeysville, MD) containing 25 μg mL−1 of kanamycin (pBAD35 constructs) or 50 μg mL−1 of ampicillin (pBAD18 constructs) and 34 μg mL−1 of chloramphenicol. All cultures were grown in a 37°C shaker at 250 rpm.