Industrial Crops and Products 34 (2011) 1160–1167 Contents lists available at ScienceDirect Industrial Crops and Products jo ur nal homep age: www.elsevier.com/locate/indcrop Value-addition of agricultural wastes for augmented cellulase and xylanase production through solid-state tray fermentation employing mixed-culture of fungi Gurpreet Singh Dhillon a,b , Harinder Singh Oberoi a , Surinder Kaur b,c , Sunil Bansal d , Satinder Kaur Brar b,∗ a Central Institute of Post Harvest Engineering & Technology (CIPHET), PAU campus Ludhiana, Punjab, India b INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec, Canada G1K 9A9 c Department of Mycology & Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University (BHU), Varanasi-221005, India d Department of Grain Science and Industry, Kansas State University, Manhattan, KS-66506, USA a r t i c l e i n f o Article history: Received 22 November 2010 Received in revised form 30 March 2011 Accepted 6 April 2011 Available online 6 May 2011 Keywords: Agricultural wastes Aspergillus niger Cellulase lignocellulosic biomass Tray fermentation Trichoderma reesei Xylanase a b s t r a c t Solid-state fermentation (SSF) was performed to evaluate the potential of agricultural residues for the production of cellulase and hemicellulase using individual and mixed cultures of Aspergillus niger and Trichoderma reseei. The maximum filter paper (FP) cellulase activity of 13.57 IU/gram dry substrate (gds), 22.89 IU/gds and 24.17 IU/gds and -glucosidase activities of 21.69 IU/gds, 13.58 IU/gds and 24.54 IU/gds were obtained with wheat bran medium at 96 h incubation period with A. niger, T. reseei and mixed- cultures of A. niger and T. reseei, respectively. Mixed-culture SSF using rice straw supplemented with wheat bran in the ratio 3:2 resulted in higher FP cellulase, -glucosidase, endoglucanase (CMCase) and xylanase activities, compared to the activities obtained using mono-cultures. Similarly, higher FP cellulase, -glucosidase, CMCase and xylanase activities of 35.8 IU/gds (96 h), 33.71 IU/gds (96 h), 131.34 IU/gds (120 h) and 3106.34 IU/gds (120 h) were achieved in the tray fermentation using rice straw with wheat bran in the ratio of 3:2. Results of present investigation showed that higher cellulase activity and an optimal combination of cellulase and -glucosidase can be achieved through mixed-culture SSF in trays. The approach of utilizing negative cost agricultural wastes through tray fermentation for cellulase and hemicellulase production is expected to serve the objectives of: (a) management of wastes which would otherwise cause environmental pollution problems; (b) production of hydrolytic enzymes at low cost and; (c) simple technique requiring no sophisticated instruments with practical applications. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Cellulases play a significant role in emerging bio-energy and var- ious other biotechnological processes, such as food, textile, paper and pulp, agriculture, and environment. However, production cost of enzymes is very high and accounts for about 40–60% of the total production cost (Hacking, 1987). According to an estimate, cel- lulases alone contribute 22.5–43.4% to the total cost of cellulosic ethanol production when enzymes are procured from commer- cial sources (Wooley et al., 1999). For this reason, the cost of pure Abbreviations: CMCase, carboxymethyl cellulase; CFW, cauliflower waste; FP cellulase, filter paper cellulase; KP, kinnow pulp; RS, rice straw; PPW, pea-pod waste; SSF, solid-state fermentation; WB, Wheat bran. ∗ Corresponding author. Tel.: +1 418 654 3116; fax: +1 418 654 2600. E-mail addresses: satinder.brar@ete.inrs.ca, garry dhillons@yahoo.com (S.K. Brar). enzyme is considered to be a major obstacle in the widespread com- mercialization of enzymatic lignocellulosic biomass hydrolysis. In the recent years, research efforts have been focused on lowering the cost of enzyme. Utilization of abundant renewable lignocellulosic biomass, especially agricultural waste residues, agro-industrial waste and their by-products as substrates can help to reduce cellu- lase prices (Rodriguez-Couto and Sanroman, 2005). Also the use of cheaper technologies like solid-state tray fermentation can further improve the production economics. SSF technology results in an enzyme preparation, which is more concentrated and hence, best suited for biomass conversion applications (Dhillon et al., 2010). Cellulases are produced by many microorganisms, such as fungi, bacteria and actinomycetes. However, due to high yields, fungi have been commercially exploited for production of these enzymes. Among fungi, Trichoderma and Aspergillus have been widely exploited for their inherent ability to produce cellulases (Duff et al., 1987; Zhang and Lynd, 2004). Bioconversion of ligno- cellulosic waste to soluble sugars relies on the synergistic action of 0926-6690/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.indcrop.2011.04.001