Fig. 4

Measurement of antioxidant enzyme activities. Measurement of catalase (CAT, (a)) and superoxide (SOD, (b)) activities in wild-type M. alhagi (WT), ΔprkA (prkA deletion mutant), and CΔprkA (complement of ΔprkA). Three independent biological experiments were conducted to measure the CAT and SOD activities. The error bars indicate standard deviations. The significance of differences is shown at the P < 0.05 level (t-test). Different lowercase letters mean significant difference between two columns