Fig 4. Effects of the cabA mutation on biofilm formation.

(A and C) Biofilms of the strains were grown for 24 h on 96-well microtiter plate wells containing VFMG-CF supplemented with or without 0.01% arabinose and with various levels of CaCl₂, and quantified using CV staining. (B) Biofilms of the strains were grown with VFMG-CF containing 0.01% arabinose and 10 mM CaCl₂, and quantified as described above. Ampicillin and kanamycin (100 μg/ml for each) were used to maintain plasmids in the strains. JN111 (pJK1113), parent strain; cabA (pJK1113), cabA mutant; cabA (pYM1109), complemented strain. **, P<0.005 relative to the JN111 biofilm. Error bars represent the SD. (D) EPS extracts were prepared from the strains grown on the LBS agar plates supplemented with 0.02% arabinose and resolved on a 4% stacking SDS-PAGE. JN111, parent strain; cabA, cabA mutant.