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Extracellular polymeric substances (EPSs) are natural polymers of high molecular weight secreted by
microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in old ...
s into their environment. EPSs establish the functional and structural integrity of
biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular po ...
s, and are considered the fundamental component that determines the physicochemical properties of a biofilm. EPS in the matrix of biofilms provides compositional support and protection of microbial communities from the harsh environments. Components of EPS can be of different classes of polysaccharides, lipids, nucleic acids, proteins, Lipopolysaccharides, and minerals.


Components

EPSs are mostly composed of polysaccharides (exopolysaccharides) and
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
s, but include other macromolecules such as DNA,
lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids in ...
s and humic substances. EPSs are the construction material of bacterial settlements and either remain attached to the cell's outer surface, or are secreted into its growth medium. These compounds are important in biofilm formation and cells' attachment to surfaces. EPSs constitute 50% to 90% of a biofilm's total organic matter. Exopolysaccharides (also sometimes abbreviated EPSs; EPS sugars thereafter) are the sugar-based parts of EPS. Microorganisms synthesize a wide spectrum of multifunctional polysaccharides including intracellular polysaccharides, structural polysaccharides and
extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...
polysaccharides or exopolysaccharides. Exopolysaccharides generally consist of monosaccharides and some non-
carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may o ...
substituents (such as acetate, pyruvate, succinate, and
phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosph ...
). Owing to the wide diversity in composition, exopolysaccharides have found diverse applications in various food and pharmaceutical industries. Many microbial EPS sugars provide properties that are almost identical to the gums currently in use. With innovative approaches, efforts are underway to supersede the traditionally used plant and algal gums by their microbial counterparts. Moreover, considerable progress has been made in discovering and developing new microbial EPS sugars that possess novel industrial applications. Levan produced by ''
Pantoea agglomerans ''Pantoea agglomerans'' is a Gram-negative bacterium that belongs to the family Erwiniaceae. It was formerly called ''Enterobacter agglomerans'', or ''Erwinia herbicola'' and is a ubiquitous bacterium commonly isolated from plant surfaces, see ...
'' ZMR7 was reported to decrease the viability of rhabdomyosarcoma (RD) and
breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or ...
(MDA) cells compared with untreated cancer cells. In addition, it has high antiparasitic activity against the promastigote of ''
Leishmania tropica ''Leishmania tropica'' is a flagellate parasite and the cause of anthroponotic cutaneous leishmaniasis in humans. This parasite is restricted to Afro-Eurasia and is a common cause of infection in Afghanistan, Iran, Syria, Yemen, Algeria, Mo ...
.'' In the1960s and 1970s, the presence of exopolysaccharides in the matrix of plaques associated with tooth decay was investigated. In the field of paleomicrobiology, dental biofilms and their EPS components provide scientists with information about the composition of ancient microbial and host biomolecules as well as the diet of the host. The minerals, results of biomineralization processes regulated by the environment or bacteria, are also essential components of the EPS. They provide structural integrity to biofilm matrix and act as a scaffold to protect bacterial cells from shear forces and antimicrobial chemicals. The minerals in EPS were found to contribute to morphogenesis of bacteria and the structural integrity of the matrix. For example, in ''Bacillus. subtilis, Mycobacterium smegmatis, and Pseudomonas aeruginosa'' biofilms calcite (CaCO3) contributes to the integrity of the matrix. The minerals also associate with medical conditions. In the biofilms of ''Proteus mirabilis, Proteus vulgaris, and Providencia rettgeri,'' the minerals calcium and magnesium cause catheter encrustation.


EPS and Biofilm


Biofilm Formation

The first step in the formation of Biofilms is adhesion. The initial bacterial adhesion to surfaces involves the adhesin–receptor interactions. Certain polysaccharides, lipids and proteins in the matrix function as the adhesive agents. EPS also promotes cell–cell cohesion (including interspecies recognition) to facilitate microbial aggregation and biofilm formation. In general, the EPS-based matrix mediates biofilm assembly as follows. First, the EPS formation takes place at the site of adhesion, it will be either produced on bacterial surfaces or secreted on the surface of attachment, and form an initial polymeric matrix promoting microbial colonization and cell clustering. Next, continuous production of EPS further expands the matrix in 3 dimensions while forming a core of bacterial cells. The bacterial core provides a supporting framework, and facilitates the development of 3D clusters and aggregation of microcolonies. Studies on ''P. aeruginosa, B. subtilis'', ''V. cholerae'', and ''S. mutans'' suggested that the transition from initial cell clustering to microcolony appears to be conserved among different biofilm-forming model organisms. As an example, ''S. mutans'' produces an exoenzymes, called glucosyltransferases (Gtfs), which synthesize glucans ''in situ'' using host diet sugars as substrates. Gtfs even bind to the bacteria that do not synthesize Gtfs, and therefore, facilitate interspecies and interkingdom coadhesion.


Significance of EPS in Biofilms

Afterwards, as biofilm becomes established, EPS provides physical stability and resistance to mechanical removal, antimicrobials, and host immunity. Exopolysaccharides and environmental DNA (eDNA) contribute to viscoelasticity of mature biofilms so that detachment of biofilm from the substratum will be challenging even under sustained fluid shear stress or high mechanical pressure. In addition to mechanical resistance, EPS also promotes protection against antimicrobials and enhanced drug tolerance. Antimicrobials cannot diffuse through the EPS barrier, resulting in limited drug access into the deeper layers of the biofilm. Moreover, positively charged agents will bind to negatively charged EPS contributing to the antimicrobial tolerance of biofilms, and enabling inactivation or degradation of antimicrobials by enzymes present in biofilm matrix. EPS also functions as local nutrient reservoir of various biomolecules, such as fermentable polysaccharides. A study on ''V. cholerae'' in 2017 suggested that due to osmotic pressure differences in ''V. cholerae'' biofilms, the microbial colonies physically swell, therefore maximizing their contact with nutritious surfaces and thus, nutrient uptake.


Function

Capsular exopolysaccharides can protect pathogenic bacteria against desiccation and
predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...
, and contribute to their
pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a g ...
icity. Sessile bacteria fixed and aggregated in
biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular po ...
s are less vulnerable compared to drifting
plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...
ic 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 Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can ...
in their natural environments. Furthermore, the EPS layer acts as a nutrient trap, facilitating
bacterial growth 250px, Growth is shown as ''L'' = log(numbers) where numbers is the number of colony forming units per ml, versus ''T'' (time.) Bacterial growth is proliferation of bacterium into two daughter cells, in a process called binary fission. Providing ...
. The exopolysaccharides of some strains of lactic acid bacteria, e.g., Lactococcus lactis subsp. cremoris, contribute a gelatinous texture to
fermented milk products Fermented milk products or fermented dairy products, also known as cultured dairy foods, cultured dairy products, or cultured milk products, are dairy foods that have been fermented with lactic acid bacteria such as '' Lactobacillus'', '' Lacto ...
(e.g.,
Viili Viili (Finnish) is a mesophilic fermented milk product found in the Nordic countries, particularly Finland. Viili is similar to yoghurt or kefir, but when left unmixed, its texture is malleable, or "long". The metabolism of the bacteria used in t ...
), and these polysaccharides are also digestible. An example of the industrial use of exopolysaccharides is the application of
dextran Dextran is a complex branched glucan ( polysaccharide derived from the condensation of glucose), originally derived from wine. IUPAC defines dextrans as "Branched poly-α-d-glucosides of microbial origin having glycosidic bonds predominantly C- ...
in panettone and other breads in the bakery industry. Apart from negative contributions of EPS in biofilms, EPS can also contribute to some beneficial functions. For example, ''B. subtilis'' has gained interest for its probiotic properties due to its biofilm which allows it to effectively maintain ''a favorable microenvironmnet in the gastrointestinal tract. In order to survive the passage through the upper gastrointestinal tract'', ''B. subtilis'' produces an extracellular matrix that protects it from stressful environments such as the highly acidic environment in the stomach. In ''B. subtilis'', the protein matrix component, TasA, and the exopolysaccharide have both been shown to be essential for effective plant-root colonization in ''Arabidopsis'' and tomato plants. It was also suggested that TasA plays an important role in mediating interspecies aggregation with streptococci.


Ecology

Exopolysaccharides can facilitate the attachment of
nitrogen-fixing bacteria Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmo ...
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 A nutrient cycle (or ecological recycling) is the movement and exchange of inorganic and organic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cycli ...
in
ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...
s. It also allows for successful invasion and
infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...
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 Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...
,
lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...
,
nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow t ...
, and
cadmium Cadmium is a chemical element with the Symbol (chemistry), symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12 element, group 12, zinc and mercury (element), mercury. Li ...
. The
binding affinity In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a mo ...
and metal specificity of EPSs varies, depending on polymer composition as well as factors such as
concentration In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', '' molar concentration'', ''number concentration'', ...
and pH. In a geomicrobiological context, EPSs have been observed to affect
precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...
of minerals, particularly
carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate ...
s. EPS may also bind to and trap particles in biofilm suspensions, which can restrict dispersion and element cycling.
Sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...
stability can be increased by EPS, as it influences cohesion, permeability, and
erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...
of the sediment. There is evidence that the
adhesion Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can ...
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 have a large impact on
biogeochemical cycling A biogeochemical cycle (or more generally a cycle of matter) is the pathway by which a chemical substance cycles (is turned over or moves through) the biotic and the abiotic compartments of Earth. The biotic compartment is the biosphere and th ...
.
Predator-prey Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
interactions between biofilms and bacterivores, such as the soil-dwelling nematode Caenorhabditis elegans, had been extensively studied. Via the production of sticky matrix and formation of aggregates, Yersinia pestis biofilms can prevent feeding by obstructing the mouth of C. elegans. Moreover,
Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic– facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. a ...
biofilms can impede the slithering motility of C. elegans, termed as 'quagmire
phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (biology), morphology or physical form and structure, its Developmental biology, developmental proc ...
', resulting in trapping of C. elegans within the biofilms and preventing the exploration of nematodes to feed on susceptible biofilms. This significantly reduced the ability of predator to feed and reproduce, thereby promoting the survival of biofilms.


Novel Industrial Use

Due to the growing need to find a more efficient and environmentally friendly alternative to conventional waste removal methods, industries are paying more attention to the function of bacteria and their EPS sugars in bioremediation. Researchers found that adding EPS sugars from
cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, bl ...
to wastewaters removes heavy metals such as
copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...
,
cadmium Cadmium is a chemical element with the Symbol (chemistry), symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12 element, group 12, zinc and mercury (element), mercury. Li ...
and
lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...
. EPS sugars alone can physically interact with these heavy metals and take them in through biosorption. The efficiency of removal can be optimized by treating the EPS sugars with different acids or bases before adding them to wastewater. Some contaminated soils contain high levels of polycyclic aromatic hydrocarbons (PAHs); EPSs from the bacterium ''Zoogloea'' sp. and the
fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately fr ...
'' Aspergillus niger'', are efficient at removing these toxic compounds. EPSs contain
enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
s such as
oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ...
and hydrolase, which are capable of degrading PAHs. The amount of PAH degradation depends on the concentration of EPSs added to the soil. This method proves to be low cost and highly efficient. In recent years, EPS sugars from marine bacteria have been found to speed up the cleanup of oil spills. During the Deepwater Horizon oil spill in 2010, these EPS-producing bacteria were able to grow and multiply rapidly. It was later found that their EPS sugars dissolved the oil and formed oil aggregates on the ocean surface, which sped up the cleaning process. These oil aggregates also provided a valuable source of nutrients for other marine microbial communities. This let scientists modify and optimize the use of EPS sugars to clean up oil spills.


List of Extracellular polymeric substances

* acetan (''Acetobacter xylinum'') * alginate (''Azotobacter vinelandii'') *
cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wa ...
(''Acetobacter xylinum'') * chitosan (''Mucorales spp.'') * curdlan (''Alcaligenes faecalis'' var. ''myxogenes'') * cyclosophorans (''Agrobacterium'' spp., ''Rhizobium'' spp. and ''Xanthomonas'' spp.) *
dextran Dextran is a complex branched glucan ( polysaccharide derived from the condensation of glucose), originally derived from wine. IUPAC defines dextrans as "Branched poly-α-d-glucosides of microbial origin having glycosidic bonds predominantly C- ...
(''Leuconostoc mesenteroides'', ''Leuconostoc dextranicum'' and ''Lactobacillus hilgardii'') * emulsan (''Acinetobacter calcoaceticus'') * galactoglucopolysaccharides (''Achromobacter'' spp., ''Agrobacterium radiobacter'', ''Pseudomonas marginalis'', ''Rhizobium'' spp. and ''Zooglea' spp.) * galactosaminogalactan (''Aspergillus spp.'') * gellan (''Aureomonas elodea'' and ''Sphingomonas paucimobilis'') * glucuronan (''Sinorhizobium meliloti'') * N-acetylglucosamine (''Staphylococcus epidermidis'') * N-acetyl-heparosan (''Escherichia coli'') * hyaluronic acid (''Streptococcus equi'') * indican (''Beijerinckia indica'') * kefiran (''Lactobacillus hilgardii'') * lentinan (''Lentinus elodes'') * levan (''Alcaligenes viscosus'', ''Zymomonas mobilis'', ''Bacillus subtilis'') * pullulan (''Aureobasidium pullulans'') * scleroglucan (''Sclerotium rolfsii'', ''Sclerotium delfinii'' and ''Sclerotium glucanicum'') * schizophyllan (''Schizophylum commune'') * stewartan (''Pantoea stewartii subsp. stewartii'') * succinoglycan (''Alcaligenes faecalis'' var. ''myxogenes'', '' Sinorhizobium meliloti'') *
xanthan Xanthan gum () is a polysaccharide with many industrial uses, including as a common food additive. It is an effective thickening agent, emulsifier, and stabilizer that prevents ingredients from separating. It can be produced from simple suga ...
(''Xanthomonas campestris'') * welan (''Alcaligenes'' spp.)


New Approaches to Target Biofilms

The application of Nanoparticles (NPs) are one of novel promising techniques to target biofilms due to their high surface-area-to-volume ratio, their ability to penetrate to the deeper layers of biofilms and the capacity to releasing antimicrobial agents in a controlled way. Studying NP-EPS interactions could provide deeper understanding on how to develop more effective nanoparticles. "smart release" nanocarriers that can penetrate biofilms and be triggered by pathogenic microenvironments to deliver drugs or multifunctional compounds, such as catalytic nanoparticles to aptamers, dendrimers, and bioactive peptides) have been developed to disrupt the EPS and the viability or metabolic activity of the embedded bacteria. Some factors that would alter the potentials of the NP to transport antimicrobial agents into the biofilm include physicochemical interactions of the NPs with EPS components, the characteristics of the water spaces (pores) within the EPS matrix and the EPS matrix viscosity. Size and surface properties (charge and functional groups) of the NPs are the major determinants of the penetration in and the interaction with the EPS. Another potential antibiofilm strategy is phage therapy. Bacteriophages, viruses that invade specific bacterial host cells, were suggested to be effective agents in penetrating biofilms. In order to reach the maximum efficacy to eradicate biofilms, therapeutic strategies need to target both the biofilm matrix components as well as the embedded microorganisms to target the complex biofilm microenvironment.


EPS in Microalgal Biofilms

EPS is found in the matrix of other microbial biofilms such as microalgal biofilms. The formation of biofilm and structure of EPS share a lot of similarities with bacterial ones. The formation of Biofilm starts with reversible absorption of floating cells to the surface. Followed by production of EPS, the adsorption will get irreversible. EPS will colonize the cells at the surface with hydrogen bonding. Replication of early colonizers will be facilitated by the presence of organic molecules in the matrix which will provide nutrients to the algal cells . As the colonizers are reproducing, the biofilm grows and becomes a 3-dimensional structure. Microalgal biofilms consist of 90% EPS and 10% algal cells. Agal EPS has similar components to the bacterial one; it is made up of proteins, phospholipids, polysaccharides, nucleic acids, humic substances, uronic acids and some functional groups, such as phosphoric, carboxylic, hydroxyl and amino groups. Algal cells consume EPS as their source of energy and carbon. Furthermore, EPS protects them from dehydration and reinforces the adhesion of the cells to the surface. In algal biofilms, EPS has two sub-categories; soluble EPS (sEPS) and the bounded EPS (bEPS) with former being distributed in the medium and the latter being attached to the algal cells. Bounded EPS can be further subdivided to tightly bounded EPS (TB-EPS) and loosely bounded EPS (LB-EPS). Several factors contribute to the composition of EPS including species, substrate type, nutrient availability, temperature, pH and light intensity.


See also

*
Extracellular matrix In biology, the extracellular matrix (ECM), also called intercellular matrix, is a three-dimensional network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide s ...
in multi-cellular organisms * Exopolymer *
Integrin Integrins are transmembrane receptors that facilitate cell-cell and cell-extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle ...
* Sea snot


References


External links


EPS, BioMineWiki
{{Webarchive, url=https://web.archive.org/web/20210108130147/http://wiki.biomine.skelleftea.se/wiki/index.php/Extracellular_polysaccharide , date=2021-01-08 Microbiology terms Bacteria Bacteriology Environmental soil science Membrane biology Biological matter Microbiology Biomolecules Polymers Water treatment