Fig 4. Arginine supplementation enhances H. influenzae ATP production.

Relative ATP production measured by luminescence (relative light units, RLU), of H. influenzae without supplementation of arginine (black), and with supplementation of 2 g/L (black dotted line), 4 g/L arginine (grey filled line) and 6 g/L arginine (grey dotted line). Luminescence (ATP production) is significantly higher in all concentrations of arginine, compared to no arginine supplementation. Significant differences were determined with a student t-test (*** p ≤ 0.001, ** p ≤ 0.01).