Figure 3.

Comparison of wild-type (WT) P. polymyxa WLY78, ∆pep-1 mutant and ∆pep-2 mutant in terms of growth rate, biofilm biomass and EPS content. (A) The growth curves of WT, ∆pep-1 and ∆pep-2 in nitrogen-free liquid medium supplemented with 200 mM glucose and 20 mM NH₄Cl. (B) Biofilm formation of WT, ∆pep-1 and ∆pep-2 after cultivation for 96 h in the same medium as described above. (C) The EPS content of WT, ∆pep-1 and ∆pep-2 in extracellular matrix. (D) The relative content of each component in the extracellular matrix composition of ∆pep-2. Results are representative of at least three independent experiments. Error bars indicate SD. Ns indicates nonsignificant. *** indicates p < 0.001.