Figure 5. Enzymatic activity of chitinase is required for regulation of Fn biofilm formation.

(A) Effect of exogenously added chitinase on biofilm formation in the negatively-charged TC plates. EC₅₀s of exogenous chitinase to WT, chiA and chiB mutants were determined to be 0.65, 0.18, and 0.21 μg/ml, respectively (n = 6). (B) Effect of exogenous chitinase on biofilm formation in the positively-charged amine plates. EC₅₀s of chitinase to WT, chiA and chiB mutants were determined to be 87.46, 0.17, and 0.15 μg/ml, respectively (n = 6). (C) Detachment of Fn biofilms after exposure to proteinase K, chitinase and DNase I (50 μg/ml) in the TC plates. Untreated control CV₅₇₀ values were 0.149±0.032, 0.588±0.012, and 0.585±0.017 for Fn WT, chiA and chiB mutants, respectively. *P<0.01 and **P<0.001 compared to control without enzyme treatment (n = 6).