User:Susanzc/sandbox

Original - "Extracellular polymeric substance"

Function
The exopolysaccharides of some strains of lactic acid bacteria, e.g., Lactococcus lactis subsp. cremoris, contribute a gelatinous texture to fermented milk products (e.g., Viili), and these polysaccharides are also digestible.

Capsular exopolysaccharides can protect pathogenic bacteria and contribute to their pathogenicity. Attachment of nitrogen-fixing bacteria to plant roots and soil particles, which is important for colonisation of rhizosphere and roots and for infection of the plant, can be mediated by exopolysaccharides as well. An example for industrial use of exopolysaccharides is the application of dextran in panettone and other breads in the bakery industry. Exopolysaccharides also have an important role in endodontic infections.

Edits - "Extracellular Polymeric Substance"

Function
Capsular exopolysaccharides can protect pathogenic bacteria against desiccation and predation, and contribute to their pathogenicity. Bacteria existing in biofilms are less vulnerable compared to planktonic bacteria, as the EPS matrix is able to act as a protective diffusion barrier. The physical and chemical characteristics of bacterial cells can be affected by EPS composition, influencing factors such as cellular recognition, aggregation, and adhesion in their natural environments. Furthermore, the EPS layer acts as a nutrient trap, facilitating bacterial growth.

The exopolysaccharides of some strains of lactic acid bacteria, e.g., Lactococcus lactis subsp. cremoris, contribute a gelatinous texture to fermented milk products (e.g., Viili), and these polysaccharides are also digestible. An example for industrial use of exopolysaccharides is the application of dextran in panettone and other breads in the bakery industry.

Ecology
Exopolysaccharides can facilitate the attachment of nitrogen-fixing bacteria to plant roots and soil particles, which mediates a symbiotic relationship. This is important for colonization of roots and the rhizosphere, which is a key component of soil food webs and nutrient cycling in ecosystems. It also allows for successful invasion and infection of the host plant.

Bacterial extracellular polymeric substances can aid in bioremediation of heavy metals as they have the capacity to adsorb metal cations, among other dissolved substances. This can be useful in the treatment of wastewater systems, as biofilms are able to bind to and remove metals such as copper, lead, nickel, and cadmium. The binding affinity and metal specificity of EPS varies depending on polymer composition, as well as environmental factors such as concentration and pH.

In a geomicrobiological context, EPS has been observed to affect precipitation of minerals, particularly carbonates. EPS may also bind to and trap particles in biofilm suspensions, which can restrict dispersion and element cycling. Sediment stability can be increased by EPS, as it influences cohesion, permeability, and erosion of the sediment. There is evidence that the adhesion and metal-binding ability of EPS affects mineral leaching rates in both environmental and industrial contexts. These interactions between EPS and the abiotic environment allow for EPS to largely impact biogeochemical cycling.

Susan Chen (talk) 20:59, 8 October 2017 (UTC)