Fig 3.

Effects of coculture on the survival of S. meliloti strains expressing different levels of EPS-I and EPS-II. The exoY^Sp or exoY exopolysaccharide-deficient strain, cocultured with a strain overproducing EPS-I (A) or with a strain expressing EPS-II (B), was challenged with H₂O₂. Survival was normalized to the average survival of the wild type. Error bars indicate standard deviations. The lowercase letter “a” above a bar indicates a significant difference from the wild type (P, <0.05); the letter “b” indicates a significant difference between coculture and culture of the exoY strain alone (P, <0.05).