Extracellular polymeric substance (EPS) matrix (EPS)

The extracellular bacterial biofilm matrix, also known as the extracellular polymeric substance (EPS) matrix, is a complex, self-produced three-dimensional scaffold that encases microbial communities (Flemming & Wingender, 2010). It is composed of a heterogeneous mixture of polysaccharides, proteins, lipids, and extracellular DNA (eDNA), which provide structural stability and facilitate adhesion to surfaces (Donlan, 2002). This matrix acts as a physical and chemical barrier, significantly contributing to antimicrobial recalcitrance by limiting the diffusion of antibiotics and protecting bacteria from host immune cells like macrophages and neutrophils (Karygianni et al., 2020). In clinical contexts, the matrix is a hallmark of chronic infections, such as those found in cystic fibrosis lungs or on indwelling medical devices (Tetz et al., 2009). Therapeutic interventions targeting the matrix involve the use of biofilm-disrupting agents, including enzymes like DNase I to degrade eDNA or glycoside hydrolases to break down polysaccharides, thereby sensitizing the resident bacteria to conventional treatments (Flemming & Wingender, 2010).

Other names

Biofilm matrixExtracellular bacterial matrixExtracellular polymeric substanceMicrobial slimeBiofilm scaffold

Enzymatic degradation of matrix components such as eDNA and polysaccharides, chelation of stabilizing divalent cations (e.g., Ca2+, Mg2+), and inhibition of matrix synthesis pathways to promote biofilm dispersal (Flemming & Wingender, 2010; Tetz et al., 2009).