Chapter 11 - Biofilm control with enzymes

Abstract

Microorganisms have the ability to multiply, attach to wet surfaces, and produce a matrix of extracellular polymeric substances (EPS), forming biofilms. The development of biofilms occurs on almost all surfaces (inanimate and living) and can cause serious problems in medical field, food industry, and systems. The multiple layers of cells and EPS confer to biofilms a complex and compact structure that hinders penetration of antimicrobial agents, decreasing their capacity to reach internal layers, and rendering them ineffective. Thus, when microorganisms form biofilms, the resistance to conventional antimicrobial agents increases significantly, and the control of those biofilms becomes hard to achieve. Besides, due to the complexity/heterogeneity of sessile communities, the application of a single strategy is considered insufficient. In this context, there is a need for new strategies, new antimicrobials, and biofilm prevention/control techniques. An ideal antibiofilm strategy should involve approaches to prevent biofilm formation, disintegrate biofilm structure, or remove preformed biofilms. Promising approaches can be based on the application of “green” and biological-based products, such as enzymes. Enzymes are applied in many fields of investigation and are known to be capable of degrading key components of the biofilm matrix. Moreover, it is recognized that the combination of enzymes with other biofilm control agents can enhance their activity. However, enzymes are specific, and to degrade the complex matrix that involves the biofilm, a mixture of enzymes is often necessary. In this chapter, the factors that play a crucial role in the resistance of biofilm-associated bacteria will be addressed. In addition, emergent strategies for biofilm control and eradication will be highlighted. As the use of biofilm-disrupting enzymes appears to be a very promising option to effectively control and eradicate microbial biofilms, a literature review for this strategy will be presented.