An in situ method for quantifying the strength and thickness of biofilms grown under controlled flow conditions

This study centres around cleaning investigations on biofilms of Escherichia coli and Burkholderia cepacia grown on polyethylene, stainless steel and glass, to detect their adherence behaviour under controlled hydrodynamic conditions. The biofilms were tested using the non-contact technique of Fluid Dynamic Gauging (FDG), which utilises flow data to estimate the adhesive (between biofilm and substrate) and cohesive (between cells and extracellular polymeric substances) strengths, and thicknesses of biofilms. The results suggest that biofilm thickness increases with time and peaks at approximately 14 days with a reduction thereafter. The confocal laser scanning microscopy results confirmed the increase number of dead cells after 21 days, hence contributing to the weakening of biofilms.
Interrupting the flow of media during biofilm development has negligible impact on the thickness but it significantly increases the strength.