Nature and Science 2013;11(5) http://www.sciencepub.net/nature 133 Screening Of Bacterial Strains For Beta-Mannanases Production In Solid State Fermentation Oladipo O. Olaniyi 1* , Festus O. Igbe 2 ,Temitope C. Ekundayo 1 and Kehinde J. Ayantola 1 1 Department of Microbiology, Federal University of Technology, P.M.B 704, Akure, Nigeria. 2 Department of Biochemistry, Federal University of Technology, P.M.B 704, Akure, Nigeria. *Corresponding author: Email: microladit@yahoo.com ABSTRACT: This study was carried out to screen bacterial strains of agricultural wastes origin for β-mannanases production in solid state conditions. The eight bacterial strains obtained from stock culture were screened for mannanase production in solid state condition. The strains with different codes were classified as Klebsiella edwardsii 1A, Bacillus substilis BS, K. edwardsii 2B, K. edwardsii X1, K. edwardsii X5, K. edwardsii X4, K. edwardsii X3 and B. polymyxa BP. Solid substrate fermentation was carried out in Erlenmeyer flask using Mandels and Weber’s medium as the moistened agent. Βeta-mannanase activity was determined by dinitrosalicylic acid method, while protein was determined by Lowry method. In the screening exercise conducted, all the 8 bacterial strains displayed mannanase activity which ranged 87.958 to 103.200 U/ml, while protein content ranged from 4.347 to 9.722mg/ml with the highest mannanase activity and protein content lied on isolate 1A. The optimal β-mannanase activities was achieved at 18 hrs of incubation for bacterial strains 1A and BP, 24 hrs for BS, X1 and X4, 30 hrs for 2B and X5, while X3 exhibited two activity peaks which was at 18 and 36 hrs of incubation. The optimal fermentation time for bacterial growth estimation was obtained at 12 hrs for 1A, 2B and X1, 18 hrs for BS, X5, X4 and BP, while 24 hrs was the best fermentation time for X3. In this study, the screened bacterial strains evaluated for mannanase production from agro-wastes elaborated considerable mannanase activity and this could be exploited for economic uses. [Oladipo O. Olaniyi, Festus O. Igbe, Temitope C. Ekundayo and Kehinde J. Ayantola. Screening Of Bacterial Strains For Beta-Mannanases Production In Solid State Fermentation. Nat Sci 2013;11(5):134-140]. (ISSN: 1545-0740). http://www.sciencepub.net/nature . 20 Key words: Bacterial strains, beta-mannanase, solid state fermentation, screening INTRODUCTION Lignocellulose is the major structural component of plant cell walls and is mainly composed of lignin, cellulose and hemicellulose, and represents a major source of renewable organic matter. The chemical properties of the components of lignocellulosics make them a substrate of enormous biotechnological value (Malherbe and Cloete, 2003). Large amounts of lignocellulosic “waste” are generated through forestry and agricultural practices, paperpulp industries, timber industries and many agro-industries and they pose an environmental pollution problem. However, the huge amounts of residual plant biomass considered as “waste” can potentially be converted into various different value-added products including biofuels, chemicals, and cheap energy sources for fermentation, improved animal feeds and human nutrients. Lignocellulytic enzymes also have an significant applications and biotechnological potential for various industries including chemicals, fuel, food, brewery and wine, animal feed, textile and laundry, pulp and paper, and agriculture (Bhat, 2000; Sun and Cheng, 2002; Beauchemin et al., 2003; Howard et al., 2003). There is a considerable interest in the biological degradation of lignocelluloses as the most abundant reusable resource in nature and its potential for industrial application (El-Naggar et al., 2006). The main carbohydrate constituents of lignocellulosic materials (cellulose, mannan, and xylan) consist of chains of β-1,4-linked pyranosyl units, which can be substituted in various forms. The β- 1,4-glycosidic bonds within the polysaccharide backbones are hydrolyzed by cellulases, mannanases, and xylanases. Cellulase can degrade beta-1,4-bond between glucose and glucose, mannanase can degrade beta-1,4-bond between mannose and mannose, xylanase degrade beta-1,4-bond between xylose and xylose (Sachslehner et al., 1998). Various mannanases from Streptomyces sp. (Takahashi et al., 1984), Bacillus subtilis (Zakaria et al., 1998), Sclerotium (Athelia) rolfsii (Sachslehner and Haltrich, 1999), Bacillus stearothermophilus (Zhang et al., 2000), Aspergillus awamori (Kurakake and Komaki, 2001), Trichoderma harzianum (Ferreira and Filho, 2004) and B. subtilis WY34 (Jiang et al., 2006) have been purified and characterized, and some genes from B. subtilis and B. stearothermophilus encoding mannanases were also cloned, sequenced and expressed (Ethier et al., 1998). Endo β-D- mannanase (EC 3.2.1.78, mannan endo-1,4-β- D- mannosidase) cleaves randomly within the-1,4-β-D- mannan main chain of galactomannan, glucomannan, and mannan (McCleary, 1988). There has been an increasing interest in the potential application of β- mannanases in the industry, because these enzymes