Vitamin e

Pseudomonas aeruginosa PAO1 and phzS::Tn strains were grown overnight in LB broth. The bacterial suspension was diluted to a density of 2 × 10⁸ CFU ml⁻¹ (0.5 McFarland density) by sterilized NS. The pyocyanin and 5‐Me‐PCA intermediate were extracted from cultures of P. aeruginosa PAO1 and phzS::Tn, and dissolved in NS as above. Before CAP treatment, 0–30 μl pigment solution was added into bacterial suspension, and then the suspension was exposed to CAP for 30 s and followed 1 h of incubation at room temperature. After that, the survival of bacterial cells was determined through the plate dilution method as described (Yang et al., 2020 (link)).
To further compare the anti‐CAP abilities of pyocyanin and its intermediates, the pure pyocyanin and PCA reagents were purchased from Sigma‐Aldrich. The vitamin E (MedChemExpress) was purchased and served as a positive control. All reagents were separately prepared as 10mM stock solution with sterilized DMSO or PBS solution and stored at −20°C. During CAP treatment assay, pyocyanin, PCA, or vitamin E solution was added to bacterial suspension at different concentrations (0, 10 nM, 1 µM, 100 µM). Then, the mixture was treated by CAP device, and the survival bacterial cells were determined.