ORIGINAL PAPER Production of Cellulases through Solid State Fermentation Using Kinnow Pulp as a Major Substrate Harinder Singh Oberoi & Yogita Chavan & Sunil Bansal & Gurpreet Singh Dhillon Received: 27 February 2008 / Accepted: 15 May 2008 # Springer Science + Business Media, LLC 2008 Abstract A study was conducted to appraise the potential of using kinnow pulp for production of cellulases by Trichoderma reesei Rut C-30. Out of the different combi- nations tried out, dried kinnow pulp supplemented with wheat bran in the ratio of 4:1 resulted in the highest filter paper cellulase (FPase) activity of 13.4 IU/gds whereas endo-1,4-β-glucanase (CMCase) activity was found to be best when kinnow pulp was supplemented with wheat bran in the ratio 3:2 using Mandel Weber (MW) medium. β- glucosidase activity of 18 IU/gds was again found to be maximum in treatment involving 3:2 ratio of kinnow pulp to wheat bran in MW medium. However, supplementing kinnow pulp with wheat bran in 3:2 using water as medium resulted in an FPase:β-glucosidase ratio of nearly 1:1 which is considered to be most appropriate for achieving ideal saccharification efficiency in case of pretreated lignocellulosic material. Thus, this study involved the utilisation of kinnow pulp for production of cellulases and demonstrated that a substrate which does not find any commercial significance and causes environmental pollu- tion due to its poor disposal holds promise as a substrate for production of cellulases. Keywords Cellulases . Kinnow pulp . Wheat bran . Trichoderma reesei Rut C-30 . Saccharification . FPase activity . β-glucosidase activity Introduction Cellulases are industrially important enzymes having application in diverse industries such as textile, paper and pulp and food industry. In food industry, cellulases in combination with pectinases have helped in better extrac- tion and clarification of fruit juices (Bhat 2000; Shah 2007). Cellulases are well known for industrial applications and are indispensable for ethanol production from lignocellulo- sics. They contribute 22.5–43.4% to the total cost of cellulosic ethanol production when procured from external sources (Ryu and Mandels 1980; Wooley et al. 1999) but the cost is drastically reduced once the in-house produced enzymes are used for saccharification purpose (Kadam 1996). Solid state fermentation (SSF) can be of special interest in processes where crude fermented product could be used directly as enzyme source. This is partly because processes involving SSF have lower energy requirements, produce less wastewater and are environmentally friendly as they resolve the problem of solid wastes disposal (Pandey 2003). Currently, industrial demand for cellulases is being met by production methods using submerged fermentation (SmF) processes, employing genetically mod- ified strains of Trichoderma. The cost of production in SmF systems is however high and it is uneconomical to use them in many of the processes such as enzyme production which necessitates reduction in production cost by deploying alternative methods such as SSF. While the production cost of cellulases in the crude fermentation by SmF was about $20/kg, it was only $0.2/kg when in situ SSF was used (Tengerdy 1998). Although an economical and high- yielding process, SSF suffers from certain drawbacks such as control of pH during growth and metabolism of the organism and operational problems during scale up. Tolan and Foody (1999) have described about the different facets Food Bioprocess Technol DOI 10.1007/s11947-008-0092-8 H. S. Oberoi (*) : S. Bansal : G. S. Dhillon Central Institute of Post Harvest Engineering and Technology, P.O. PAU, Ludhiana 141 004, India e-mail: hari_manu@yahoo.com Y. Chavan Sant Longowal Institute of Engineering and Technology (SLIET), Sangrur, Punjab, India