Effect of heterologous protein expression on Escherichia coli biofilm formation and biocide susceptibility

Abstract

Escherichia coli is recognized as an excellent model for biofilm studies and one of the favourite hosts for recombinant protein expression. This work assesses the influence of heterologous protein production on biofilm formation and susceptibility to chemical treatment. Biofilm formation by two E. coli strains was compared using a flow cell system. One strain contained the commercial pET28A plasmid and the other a plasmid derivative with the same backbone but containing the enhanced green fluorescent protein (eGFP) gene. The susceptibility of biofilms to the biocide benzyldimethyldodecylammonium chloride (BDMDAC) was also assessed. It was found that the eGFP-expressing strain formed thicker biofilms with a higher cell density than the non-producing strain. Biofilms of both strains were neither completely inactivated nor removed by biocide treatment. Similar inactivation efficiencies were obtained, although biofilm cohesion was higher for the nonproducing strain.