Fig. 2. Effects of l-lysine on the O2− content, MDA content and SOD activity of M. aeruginosa cells. Cells were treated with 0.5, 3.0, 5.0, 6.5, and 8.0 mg L−1l-lysine. M. aeruginosa without l-lysine treatment served as a control. Data presented are expressed as the mean ± standard deviation. Significant differences between the test and control groups are indicated by asterisks, * when p < 0.05, and ** when p < 0.01.
