Abstract
The extracellular matrix of microbial biofilms has traditionally been viewed as a structural scaffold that retains the resident bacteria in the biofilm. Moreover, a role of the matrix in the tolerance of biofilms to antimicrobials and environmental stressors was recognized early in biofilm research. However, as research progressed it became apparent that the biofilm matrix can also be involved in processes such as bacterial migration, genetic exchange, ion capture and signalling. More recently, evidence has accumulated that the biofilm matrix can also have catalytic functions. Here we review foundational research on this fascinating catalytic role of the biofilm matrix.