ABSTRACT
Cellulose is a chemically stable polymer. Its glycosidic bonds are strong and stable under various reaction conditions. However, cellulose can be degraded in Nature by enzymes as an essential part of the carbon cycle, and non-biologically by acids, alkalis, oxidants, mechanical means, thermal energy and radiations. [1, 2]
In a typical cellulose-degrading ecosystem, a variety of cellulolytic bacteria and fungi work in association with related microorganisms to convert insoluble cellulose to soluble sugars, primarily cellobiose and glucose, which are then assimilated by the cell. [1] For catalyzing this process, the cellulolytic microbes produce a wide diversity of enzymes, known as cellulases. Cellulases catalyze the hydrolysis of the b-1,4-glucosidic linkages in cellulose. They are members of the glycoside hydrolase (GH) families of enzymes that hydrolyze the polysaccharides in plant cell walls. [2] Due to the structural complexity and rigidity of cellulosic
substrates, their efficient degradation generally requires multienzyme systems. Such systems include either a collection of free cellulases or/and multicomponent complexes called cellulosomes.
