RNA Isolation from P. aeruginosa

Total RNA was isolated from the P. aeruginosa wild type or mutant strains as formerly explained (Ducret et al., 2020 (link)). Briefly, overnight cultures were diluted to an optical density at 600 nm (OD₆₀₀) of 0.1 and grown for 2 h 30 min in M-LB containing 30 μM TPEN. 0.5 mL of each culture was mixed with 1 mL of RNA Bacteria Protect Reagent (Qiagen) immediately after 2 mM ZnCl₂ induction (t0) and after several time points as indicated in the different figures. Total RNAs were extracted with an RNeasy mini kit (Qiagen) according to the manufacturer’s instructions. 5 μg of total RNA were treated with RQ1 RNase-free DNAse (Promega) for 2 h at 37°C, followed by phenol/chloroform extraction and ethanol precipitation.