Fig 6. LXG toxin–antitoxin systems specifically function in biofilms.

(A) Competition assays with the wild-type strain and LXG toxin–antitoxin deletion mutants on three different solid media. (B) Competition assays with the wild-type strain and LXG toxin–antitoxin deletion mutants in liquid shaking culture. Strains were co-cultured for 24 h in liquid MSgg medium with vigorous shaking. (C) Biofilm matrix polymers were required for LXG toxin function. Competition assays were conducted in the ΔepsA–O (top) or ΔtapA–tasA (bottom) mutant backgrounds. Percentages are presented as mean ± standard deviation (n = 3).