Non-disruptive matrix turnover is a conserved feature of biofilm aggregate growth in paradigm pathogenic species

Here, we show that, to accommodate growing cellular biomass, newly produced Psl is deposited over existing Psl at the periphery of biofilm aggregates. We demonstrated that <i>V. cholerae</i> employs a similar mechanism with its biofilm matrix EPS, VPS. In addition, we found that the protease LasB is present in the biofilm matrix, resulting in degradation of CdrA to lower molecular weight cell-free forms. We then show that the released forms of CdrA are retained in the matrix and remain functional. Together, our findings support that the <i>P. aeruginosa</i> biofilm matrix is dynamic during the course of aggregate growth and that other species may employ similar mechanisms to remodel their matrix.