Exopolysaccharides Production by Lactic Acid Bacteria

Exopolysaccharides (EPSs) are high molecular weight and biodegradable polymers. They are biosynthesized by a wide range of bacteria. Lactic acid bacteria (LAB) are also able to produce EPSs. EPSs can be classified into two groups. These are homopolysaccharides and heteropolysaccharides. Homopolysaccharides are polymers which are composed of one type of monosaccharide. Heteropolysaccharides are polymers of repeating units. They are composed of two or more types of monosaccharides. Producer microorganisms don’t use the bacterial EPSs as energy sources. EPSs have been used in the production of several fermented foods such as thickeners, stabilizers, emulsifiers and gelling or water-binding agents. In addition, EPSs have some positive effects on health. These are to have antitumor effects, immune-stimulatory activity and to lower blood cholesterol. Incubation temperature and time, growth medium, acidity of growth medium and type of strain have an impact on EPSs production. In this review, EPSs production by LAB, including chemical composition, structure, biosynthesis, genetics and application of EPSs produced by LAB is discussed.