Bacterial Extracellular Polysaccharides Involved in Biofilm Formation

Abstract

Extracellular polymeric substances (EPS) produced by microorganisms are a complex mixture of biopolymers primarily consisting of polysaccharides, as well as proteins, nucleic acids, lipids and humic substances. EPS make up the intercellular space of microbial aggregates and form the structure and architecture of the biofilm matrix. The key functions of EPS comprise the mediation of the initial attachment of cells to different substrata and protection against environmental stress and dehydration. The aim of this review is to present a summary of the current status of the research into the role of EPS in bacterial attachment followed by biofilm formation. The latter has a profound impact on an array of biomedical, biotechnology and industrial fields including pharmaceutical and surgical applications, food engineering, bioremediation and biohydrometallurgy. The diverse structural variations of EPS produced by bacteria of different taxonomic lineages, together with examples of biotechnological applications, are discussed. Finally, a range of novel techniques that can be used in studies involving biofilm-specific polysaccharides is discussed.

In vitro characterization of aggregation and adhesion properties of viable and heat-killed forms of two probiotic Lactobacillus strains and interaction with foodborne zoonotic bacteria, especially Campylobacter jejuni

“…EPS are produced by many bacterial species from various ecological niches and have been described as cement for biofilm formation (Vu et al, 2009). Data obtained in this study suggest that autoaggregation of Lb.…”

The Structure- and Metal-dependent Activity of Escherichia coli PgaB Provides Insight into the Partial De-N-acetylation of Poly-β-1,6-N-acetyl-d-glucosamine

“…1C). Structural alignment of the N-terminal domain with the CE4 peptidoglycan deacetylase PgdA from Streptococcus pneumoniae (SpPgdA) (25) shows strong conservation of both the canonical (␤/␣) 7 fold and the active site, with RMSDs of 2.6 Å (over 141 equivalent C␣ atoms) and 0.6 Å (over 11 equivalent C␣ atoms), respectively (Fig. 2, A and B).…”

“…The extracellular matrix facilitates the adherence between bacteria and the surfaces they colonize while also providing protection against environmental stresses, a diffusion barrier against antibiotics, and isolation from the innate immune system (4,5). The composition of the extracellular matrix can be quite diverse, but exopolysaccharides are a key component for the development and structural integrity of most biofilms (6,7). A wide variety of medically important biofilm-forming bacteria produce partially de-N-acetylated poly-␤-1,6-N-acetyl-D-glucosamine (dPNAG) 5 exopolysaccharides, also referred to as polysaccharide intercellular adhesin.…”

Phaeobacter gallaeciensis genomes from globally opposite locations reveal high similarity of adaptation to surface life

“…Extracellular polysaccharides represent a major factor contributing to surface attachment (Danhorn and Fuqua, 2007;Vu et al, 2009). Variation in its composition, as indicated by unique genes and gene combination, might facilitate hostspecific association of P. gallaeciensis (Skorupska et al, 2006).…”