Production of Cellulolytic Enzymes

BioEnergy Science Center, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA 

Department of Biochemicai Engineering and Biotechnology, Indian Institute of Technology Delhi, New Deihi, india 

Desirable Attributes of CeUulase for Hydrolysis of Cellulose Strategies Used for Enhanced Enzyme Production 

2 Process Methods Economic Outlook Future Prospects References 

Bioprocessing of Renewable Resources to Commodity Bioproducts, First Edition. Edited by Virendra S. Bisaria and Akihiko Kondo. 

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The filamentous fungi investigated showed coinduction of cellulolytic and xylanolytic enzymes. During growth on cellulose, products from the hydrolysis of cellulose also induced production of xylanolytic enzymes, and during growth on xylan, products from the hydrolysis of xylan also induced the production of cellulolytic enzymes. 

Recently Lan et al. (2013) smdied the production of cellulolytic enzymes by Trichoderma viride in a rotating fibrous-bed bioreactor (RFBB) and compared its performance with that of an STR. It was envisaged that the immobilization of T. viride mycelia on solid support of polypropylene cloth would eliminate some of the difficulties associated with the use of STRs (such as disintegration of the mycelia by the impeller, fouling of the pH and temperature probes, and clogging of the sample... 

In the treatment of cellulose pulps one essential criterion for a suitable enzyme preparation is that its cellulase activity should be as low as possible, or preferably absent completely. As even extremely low cellulase activities may ruin pulp quality, Trichoderma enzyme preparations are unlikely to be suitable for these applications. Many bacterial and fungal enzymes with low cellulase activity have been shown to be suitable for treatment of pulps 14, 15, 16,17), Regulation of the often synchronous production of cellulolytic and hemicellulolytic enzymes in micro-organisms is not well understood, and is further complicated by substrate cross-specificity of these enzymes. Enzymes with both endoglucanase and xylanase activity have been reported for bacteria 18, 19) and fungi 20, 21, 22), In addition to selection of strain and... 

Because of its ability to produce and secrete the complete set of cellulolytic enzymes, thus making it particularly potent in hydrolyzing the cellulose polymer to glucose monomers, the soft-rot fungus Trichoderma, in particular T. reesei has been the focus of cellulase research for decades (8). The preferred substrates used by most researchers for cellulase production are pure celluloses such as Avicel, Solka-floc, and cotton (9). Cellulase production by Trichoderma is controlled by a complex metabolic regulation (10-12). Cellulose acts (indirectly) as an inducer for the production of cellulases. Expression of cellulases is furthermore subject to repres-... 

Teunissen MJ, Smits AA, Op den Camp HJ, Huis in t Veld JH, Vogels GD (1991) Fermentation of cellulose and production of cellulolytic and xylanolytic enzymes by anaerobic fungi from ruminant and non-ruminant herbivores. Arch Microbiol 156 290-296 Tielens AG, Rotte C, van Hellemond JJ, Martin W (2002) Mitochondria as we don t know them. Trends Biochem Sci 27 564-572... 

Figure 4 Comparative analysis of glucose and gluconic acid production from cellulose demonstrating inhibition of cellulolytic enzymes by cellulose hydrolysis products...

Panagiotou G, Kekos D, Maoris BJ, Christakopoulos P. (2003). Production of cellulolytic and xylanolytic enzymes by Fusariwn oxysporum grown on com stover in solid state fermentation. Ind Crops Prod, 18, 37-45. 

Siinivasan K, Murakami M, Nakashimada Y, Nishio N. (2001). Efficient production of cellulolytic and xylanolytic enzymes by the rumen anaerobic fungus, Neocallimastix frontalis, in a repeated batch culture. J Biosci Bioeng, 91, 153-158. 

A wild strain Aspergillus terreus isolated from wood drifted ashore in India (Araujo and D Souza, 1980) exhibits an increased production of 3-glucosidase as compared with other known producers of cellulases. Therefore, in our studies of cellulases we concentrated on this organism. We first determined the effect of cultivation conditions on the properties and production of individual enzymes of the cellulolytic complex (D Souza and... 

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