African Journal of Biochemistry Research Vol.1 (4), pp. 048-053, September 2007 Available online at http://www.academicjournals.org/AJBR © 2007 Academic Journals Full Length Research Paper Xylanase production by Penicillium chrysogenum (PCL501) fermented on cellulosic wastes Okafor, U. A. 1 , Emezue, T. N. 1 , Okochi, V. I. 1 ; Onyegeme-Okerenta, B. M. 1 and Nwodo- Chinedu, S. 2 * 1 Department of Biochemistry, College of Medicine, University of Lagos, PMB 12003 Idiaraba, Lagos, Lagos State, Nigeria. 2 Department of Biological Sciences, College of Science and Technology, Covenant University, KM 10 Idiroko Road, Canaan Land, PMB 1023 Ota, Ogun State, Nigeria. Accepted 20 August, 2007 Xylanase production by Penicillium chrysogenum PCL501, newly isolated from wood-wastes, was monitored at 24 h intervals for a period 168 h in media containing four different carbon sources (oat- spelt xylan, wheat bran, sawdust, and sugarcane pulp). The highest xylanase activity of 6.47 Units mL -1 was obtained at 96 h in media containing wheat bran whereas media containing sugarcane pulp gave a peak value of 1.39 Units mL -1 at 144 h. Sawdust and xylan gave a peak xylanase activity of 1.35 and 0.79 Units mL -1 respectively at 120 h. Maximum protein released in xylan-containing media was 0.38 mg mL -1 . Higher protein yield was obtained in media containing the agro-wastes, with wheat bran giving the highest value of 1.14 mg mL -1 . The maximum specific xylanase activities were 2.59, 8.52, 16.06, and 9.36 Units mg Protein -1 for sawdust, sugarcane pulp, wheat bran and xylan respectively. Out of the three agro-wastes used in this study, wheat bran holds the greatest promise for cost-effective production of the xylanase enzyme. The carbon source is the highest inducer of the enzyme in the fungus. Key words: Penicillium chrysogenum PCL501, agro-wastes, wheat bran, sawdust, sugarcane pulp, xylanase. INTRODUCTION Xylanolytic enzymes are receiving increasing attention because of their potential applications in improving diges- tibility of animal feed (Wong et al., 1988), pulp bleaching (Rifaat et al., 2005) and bioconversion of lignocelluloses into feed-stocks and fuels (Kim et al., 2000). Principal xylanolytic enzymes are endo--xylanases (EC 3. 2. 1. 8), which attack the main chain of xylans, and -xylosi- dases (EC 3. 2. 1. 37), which hydrolyze xylooligo- saccharides into D-xylose. Several studies have shown that the xylanases are co-induced in response to xylan or natural substrates containing hemicellulose or even by pure cellulose (Atev et al., 1987; Ganju et al., 1989; Kadowaki and Souza, 1997). The use of waste plant materials as carbon sources in fermentation media is being studied as a cost-effective strategy for the prod- uction of the enzymes. Xylanases have been produced by Candida utilis using apple pomace (Villas-Boas et al., *Corresponding author. E-mail: sncresearch@yahoo.com. Tel: +234-(0)802- 862-6605. 2002) and by Pleurotus species using banana wastes (Reddy et al., 2003). Xylan-rich natural substrates such as sawdust (Yu et al., 1987), corncob (Bennett et al., 1998), wheat bran (Seyis and Aksoz, 2005), sugar beet pulp (Tuohy et al., 1993), and sugarcane pulp or baggase (Prabhu and Maheshwari., 1999) have been used to stimulate xylanase production by different organisms. Many filamentous fungi secrete high levels of plant cell wall hydrolyzing enzymes such as cellulases and xyla- nases into their culture media, and are employed for the hydrolysis of ligncellulosic materials (Berry and Paterson, 1990). In a search for microorganisms capable of degra- ding lignocelluloses in our environment, cellulolytic micro- fungi, including a strain of Penicillium chrysogenum (PCL501), were isolated from decomposing wood-wastes and characterized (Nwodo-Chinedu et al., 2005). The fungus grows effectively and produces extracellular pro- teins with cellulase activities in basal media containing cellulose, sawdust and sugarcane pulp (Nwodo-Chinedu et al., 2005; Nwodo-Chinedu et al., 2007a; Nwodo-Chine- du et al., 2007b). In this study, the effect of different agro- wastes on the production of xylanase enzyme (EC 3. 2.