Exopolysaccharide Production by Thermophilic Microorganisms

Abstract

In recent years, the demand for natural polymers for various industrial applications led to increased interest in microbial exopolysaccharide (EPS) production. Several microorganisms have the ability to synthesize extracellular polysaccharides either as soluble or insoluble polymers. Among those, EPS from thermophilic microorganisms are of special interest owing to its advantages such as short fermentation time, better oxygen mass transfer, decreased viscosity of synthesized polymer and the corresponding culture and the non-toxic nature of the polymer allowing applications in food and pharmaceutical industries. Despite this interest, there is very limited knowledge on EPS biosynthesis mechanisms by thermophilic bacteria, as opposed to the vast amount of reports on mesophilic EPS producers. In this chapter, a brief overview of life under extreme environmental conditions especially high temperatures is presented. This is followed by a discussion of thermophilic microorganisms and their adaptation mechanisms, and specifically focuses on the production of EPSs and their ecological and physiological functions. The application areas of industrially important EPSs from various thermophilic producer strains are also mentioned.