Probing the Surface-Attached In Vitro Microbial Biofilms with Atomic Force (AFM) and Scanning Probe Microscopy (SPM)

Abstract

AbstractBacterial adhesion on to the various biotic or abiotic surfaces and subsequent biofilm formation paves the path of microbial contamination in various clinical and industrial environments. The mode of biofilm formation and propagation depends on various factors such as availability of nutrient sources, ambient environmental conditions such as temperature, pH, salinity, and coping with the presence of various antimicrobials of the surroundings. Biofilm formation is a cell density dependent signaling mechanism under extreme stress conditions for survival of microorganisms. They consist of proteins, nucleic acids, polysaccharides, and lipids that are constantly being exchanged between the neighboring bacterial cells enclosed within a matrix of extracellular polymeric substances (EPS). The mechanism of bacteria–surface interaction can be best described by the advancements of microscopic techniques. This chapter will focus on the recent developments on the diverse and powerful tools such as atomic force microscopy (AFM) and surface probe microscopy (SPM) for understanding the nanoscale adhesive forces dominating the behavior and structure of biofilms and shedding light on the biofilm control strategies within clinical and industrial environments. These newer visualization techniques allow us with the opportunities of observing topographical landscape of bacterial cells through image heights, resolved structures of surface macromolecules, nanomechanical properties of microbial adhesion forces, and mode of receptor–ligand interaction (antibiofilm compounds) at the biofilm interface.