text: EPSs are mostly composed of polysaccharides (exopolysaccharides) and proteins, but include other macromolecules such as DNA, lipids and humic substances.  EPSs are the construction material of bacterial settlements and either remain attached to the cells 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 polysaccharides or exopolysaccharides. Exopolysaccharides generally consist of monosaccharides and some non-carbohydrate substituents (such as acetate, pyruvate, succinate, and phosphate). 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 ZMR7 was reported to decrease the viability of rhabdomyosarcoma (RD) and breast cancer (MDA) cells compared with untreated cancer cells. In addition, it has high antiparasitic activity against the promastigote of Leishmania tropica. 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 () 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.