Microbial Biopolymers: The Exopolysaccharides

Microorganisms produce several biopolymers. Of these, intracellularly produced polyhydroxyalkanoates (PHAs) and extracellularly produced exopolysaccharides (EPS) are gaining importance over the other biopolymers. These naturally produced polymers can replace plant-based or petroleum-derived polymers. There are innumerable reports and reviews on the production of PHA and EPS by several bacteria, fungi, actinomycetes, and algae. This chapter briefly gives an introduction to PHA and provides recent developments in the genetic and metabolic pathways for the synthesis of microbial EPS. Different strategies used for fermentative production and various means of downstream processing are discussed. Possible ways to minimize the cost of production and downstream processing are covered in this chapter. Applications of these EPS in various fields such as agriculture, cosmetics, foods, medical and healthcare industry, mining, oil recovery, packaging, pharmaceuticals, printing and textile industry, wastewater treatment, etc., are presented. The potential of these polymers indicates that these microbial cell factories can be exploited for the better of mankind.