FIGURE 2.

Effect of proteinase K and DNase I on structure maintenance of the biofilms formed by Aeromonas. (A) After forming the biofilms of various Aeromonas strains, either proteinase K (100 μg/mL) or DNase I (100 units/mL) was added to the medium to examine the disintegration of the biofilms. Since Mg²⁺ is required for the expression of DNase I activity, the effect of adding Mg²⁺ alone was also examined as a control experiment in the absence of DNase I. (B) Degradation of eDNAs and proteins in the ECMs by the addition of DNase I (DNase+) and proteinase K (PK+), respectively, was verified by agarose gel electrophoresis (upper panel) and SDS-polyacrylamide gel electrophoresis (lower panel), respectively. The arrowhead indicates proteinase K (PK). The protein bands in the SDS-polyacrylamide gel were visualized with fluorescence reagent (Oriole Fluorescent Gel Stain; Bio-Rad, Hercules, CA, United States).