Toxoflavin and UV radiation tolerance
Overnight cultures of the PA13 derivatives were sub-cultured and grown for an additional 12 h. A 100-μL aliquot was removed and serially diluted 10-fold, and 10-μL of each culture was spotted on LB agar plates supplemented with 20 μg mL−1 toxoflavin. The spotted plates were incubated at 28°C for 36 h.
For the UV radiation tolerance assays, PA13 derivatives were spotted on LB plates using the above procedure and treated as previously described (Mohammadi et al ., 2012).