Structure and functional characteristics of bacterial biofilms in fluid processing operations.

Bacterial biofilms create a number of serious problems for industrial fluid processing operations. Mechanical blockages, impedance of heat transfer processes, and biodeterioration of the components of metallic and polymeric systems result in billions of dollars in losses each year. Product spoilage and possible risks to public health are also consequences of biofilm-mediated contamination. Fundamentally, these biofouling activities can be described in terms of the physicochemical properties that are associated with bacterial metabolism and biofilm development. Treatment of biofouling is also complicated by the unique structural attributes of biofilms: extracellular polymeric substances create diffusional barriers to antimicrobial agents, protecting labile cellular targets from both oxidizing and nonoxidizing compounds. The mechanisms associated with the initial events of bacterial adhesion to engineered surfaces and subsequent fouling of biofilm formation are poorly understood. However, studies of bacterial biofilm architecture have been greatly facilitated by the application of confocal laser microscopy, scanning or transmission electron microscopy, and Fourier transform infrared spectroscopy. This paper reviews the genesis of biofilm formation and describes the influence of structure on biofouling activities in industrial fluid handling systems.