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INTRODUCTION
Cellulases are the enzymes capable of hydrolyzing the cellulose into smaller sugar components. Cellulolytic enzyme is complex of enzymes such as exoglucanase, endoglucanase, and beta glucosidase which plays an important role in the natural biodegradation of lignocellulosic materials (Lynd et al., 2002). The Cellulase enzymes degrade the ß-1,4-glycosidic linkage of cellulose and convert them in to glucose monomers thus overcoming the problems of their complex structure (Gao et al., 2008; Kim et al., 2008; Imran et al., 2017).
These enzymes can be synthesized by the microorganisms on different cellulose containing substrates (Koo, 2001). Filamentous fungi also have the potential of utilizing cellulosic material as the source of carbon and energy and produce cellulase enzyme (Alriksson et al., 2009). In the cellulase production mechanism fungi are used their elongated hyphae to exert mechanical pressure on the cellulose structure and as a result inflicting fungi produced massive supply of cellulase (Sanche, 2009; Idris et al., 2017). Production of cellulases from various fungi and bacteria (Penicillium spp., Aspergillus spp., Trichoderma, Pseudomonas fluorescens, Bacillus subtilis, E. coli, and Serratia marscens) for industrial use is in practice (Henriksson et al., 1999; de Lima et al., 2005; Imran et al., 2011; Sethi et al., 2013; Gunny et al., 2015; Imran et al., 2016; Imran et al., 2018; Imran et al., 2018).
Different types of defined substrates can be used for fermentation however, agro-industrial wastes are also most often used due to their abundant availability and recycling purpose (Acharya et al., 2008; Lu et al., 2010; Gautam et al., 2011). Agricultural waste such as rice straw, coffee husk, corn cobs and corn Stover are also used as substrate (Milala et al., 2005; Sanche, 2009). Cellulases are most attributed and third most widely used industrial enzymes. Different methods are in practice for cellulase production and Solid state fermentation (SSF) is one of the most commonly used method for its production. SSF is cost effective and time saving method as reported by Brijwani and Vadlani, (2011). About 3.5 billion tons of Cellulase is produced annually by the solid state fermentation method. The advantage of exploitation of SSF is to get lowest cost fermentation system and likelihood to use it at industrial scale (Graminha et al., 2008).
These enzymes are used in processing of...