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.

https://www.mdpi.com/1420-3049/14/7/2535/pdf

Bacterial extracellular polysaccharides involved in biofilm formation.

Isolation, structural characterization and immunological activity of an exopolysaccharide produced by Bacillus licheniformis 8-37-0-1.

Blends and composites of exopolysaccharides; properties and applications: A review

Optimization of culture medium and modeling of curdlan production from Paenibacillus polymyxa by RSM and ANN.

Chemistry and microbial sources of curdlan with potential application and safety regulations as prebiotic in food and health.

β-1,3-Glucan (curdlan) is a water-insoluble polysaccharide composed exclusively of β-1,3 linked glucose residues. Extracellular curdlan was mostly synthesized byAgrobacterium species andAlcaligenes faecalis under nitrogen-limiting conditions. In this study, we screened the microorganisms capable of producing extracellular curdlan from soil samples. For the first time, we reported Gram-positive bacteriumBacillus sp. SNC 107 capable of producing extracellular curdlan in appreciable amounts. The effect of different carbon sources on curdlan production was studied and found that the yield of curdlan was more when glucose was used as carbon source. It was also found that maximum production was achieved when the initial concentration of ammonium and phosphate in the medium was 0.5 and 1.9 g/L respectively. In this study the curdlan production was increased from 3 to 7 g/L in shake flask cultures.

Kislay Kumar

Papers

Production of extracellular water insoluble β-1,3-glucan (curdlan) fromBacillus sp. SNC07