FIG. 2.

Colonization of squid pens by a WT and a TCP⁻ mutant strain of V. cholerae. (A) Biofilm development over a 96-h period. Biofilm biomass was estimated by measuring the fluorescence from gfp-tagged cells (expressed as relative fluorescence units [RFUs]). (B) Chitinase activity associated with biofilm cells of the WT and TCP⁻ mutant strains during the colonization of squid pens. Specific activities of units of chitinase activity (U, described as the amount of enzyme that released 1 pmol of 4MU per min under the assay conditions) per RFU are shown. (C) Immunodetection of TcpA, the TCP pilin subunit, in biofilm cells in the course of 96 h and in planktonic cells at 24 h (Plank). (D) Immunodetection of TcpA in cultures grown under TCP-inducing conditions (AKI medium) or grown for 24 h in the absence of a chitinous surface in NG2 mineral medium with lactate and NH₄Cl (L/N) or with colloidal chitin (CollCh), and in LB medium.