Phytochemicals in biofilm inhibition

Abstract

Microbial biofilms are a collection of cells adhering to a substrate and are encased in a matrix of self-produced extracellular polymeric substances (EPSs). Biofilm development is a complicated process that is dependent on various factors such as substrate surface properties, temperature, pH, bacterial strain, etc., and it necessitates the coordinated expression of many different genes. Biofilms form on a variety of biotic and abiotic surfaces, and once formed, these biofilms show a dramatic increase in their physical and chemical resistance with increased protection toward antimicrobial agents, detergents, and sanitizing agents. In industry, besides cleaning and hygiene issues biofilm formation can cause energy loss by clogging, reduced heat transmission, and impaired flow. Moreover, the presence of biofilm in food contact surfaces can act as a source for cross-contamination, leading to intoxications or infections and thereby putting human health at risk. As decontamination of biofilm from food contact surfaces using traditional sanitizers is time-consuming, cost-intensive, and corrosive, industries today are looking forward toward more efficient alternatives. Certain plant-derived molecules like plant phenolics, flavonoids, terpenes, quinones, etc., have been reported to have biofilm inhibition properties, and they do so either by impairing the cell–cell signaling (quorum sensing), substrate surface modification, or by cell inactivation. This chapter deals with the biofilm inactivation by plant phytochemicals, along with its mode and mechanism of action.