Cellulases other microbes

Through the techniques of recombinant DNA technology, the expression of one or more cellulase components can be enhanced or deleted [44]. Alternatively, a cellulase component can be expressed in a microbe that does not otherwise make cellulase, to make a pure component. An example of this is Humicola EG5 expressed in Aspergillus oryzae [17]. The resulting pure endoglucanase is free of other cellulase components and more easily controlled in detergent applications. 

In the submerged fermentation process for cellulase production, crystal cellulose and paper pulp are commonly used substrates which are expensive. The solid-state fermentation for cellulase production should use a cheap medium. Because cellulase is an inducible enzyme, the inducer must be included in the medium. Cellulose is the best inducer [45,46] and its hydrolysate (glucose) is the carbon source for microbes to grow therefore, cellulosic material is the basic component in the medium. Complex nitrogen sources are used to supply nitrogen and to regulate the pH value. Other nutrient salts, such as Mn + and Zn etc., should also be involved in the medium. 

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