Exocellular, microbial polysaccharides.

Publisher Summary This chapter emphasizes on the microbial exopolysaccharides that are produced commercially and those whose potential for commercialization is very likely. The general background of polysaccharides and microbial polysaccharides having antitumor activity is discussed in the chapter. A common feature of bacteria, fungi (yeasts and molds), and higher living organisms is the production of polysaccharides. Morphologically, there are three types: intracellular polysaccharides located inside or as part of the cytoplasmic membrane, cell-wall polysaccharides, and exocellular polysaccharides located outside the cell wall. Some exocellular polysaccharides are found covalently attached to the cell as a true capsule, whereas others are secreted unattached into the growth medium. In some cases, both capsular and unattached exopolysaccharides can be found associated with the same microbe. The expected rising cost of petroleum-derived, synthetic polymers has now elicited interest in natural polymers from replenishable resources. Microbial polysaccharides are also increasingly being used in the recovery of crude oil.