The aim of this work is to select filamentous fungal strains isolated from saw dust, soil, and decaying wood with the potential to produce xylanase and cellulase enzymes. A total of 110 fungi were isolated. Fifty-seven (57) of these fungi were isolated from soil samples, 32 from sawdust, and 19 from decaying wood. Trichoderma and Aspergillus had the highest relative occurrence of 42.6% and 40.8%, respectively. Trichoderma viride Fd18 showed the highest specific activity of 1.30？U？mg？1 protein for xylanase, while the highest cellulase activity of 1.23？U？mg？1 was shown by Trichoderma sp. F4. The isolated fungi demonstrated potential for synthesizing the hydrolytic enzymes. 1. Introduction Xylan is a noncrystalline complex polysaccharide consisting of a backbone of -D-1, 4-linked xylopyranoside units substituted with acetyl, glucuronosyl, and arabinosyl side chains [1]. Xylans are the main carbohydrate in the hemicellulosic fraction of vegetable tissues and form an interface between lignin and the other polysaccharides. The polysaccharides are mainly found in secondary plant cell walls, and their characteristic of adhesion helps to maintain the integrity of the cellular wall [2]. Cellulose is a linear polymer of D-glucose units linked by 1, 4- -D-glucosidic bond and is crystalline in nature [3]. Cellulose is the main constituent of plants and thus the most abundant biopolymer on earth comprising approximately 35–50% of plant dry weight [4]. Hydrolysis of xylan and cellulose are essential steps towards the efficient utilization of lignocellulosic materials in nature. Lignocellulosic waste forms a large proportion of solid waste in our cities, thus constituting an environmental problem. Studies have shown that conventional waste treatment strategies have failed to ameliorate this problem. The use of microbial enzymes in lignocellulosic waste treatment has been shown to be an alternative that is efficient and cost-effective. Therefore, considering the industrial potentials of xylanases and cellulases, and their potential use in lignocellulolytic waste treatment, it becomes imperative to obtain new enzymes and enzyme-producing microbial strains that produce highly active xylanases and cellulases at low cost. Chemical hydrolysis of lignocellulose is accompanied with the formation of toxic components that are toxic to the environment [5], hence the need to explore the use of microorganisms and their enzymes, which have high specificity, mild reaction conditions, negligible substrate loss, and side product generation and are environmentally friendly [6], in
References
[1]
D. C. la Grange, M. Claeyssens, I. S. Pretorius, and W. H. van Zyl, “Degradation of Xylan to D-Xylose by recombinant Saccharomyces cerevisiae coexpressing the Aspergillus nigerβ-Xylosidase (xlnD) and the Trichoderma reesei Xylanase II (xyn2) genes,” Applied and Environmental Microbiology, vol. 67, no. 12, pp. 5512–5519, 2001.
[2]
A. J. Goulart, E. C. Carmona, and R. Monti, “Partial purification and properties of cellulase-free alkaline xylanase produced by Rhizopus stolonifer in solid-state fermentation,” Brazilian Archives of Biology and Technology, vol. 48, no. 3, pp. 327–333, 2005.
[3]
S. B. Leschine, “Cellulose degradation in anaerobic environments,” Annual Review of Microbiology, vol. 49, pp. 399–426, 1995.
[4]
L. R. Lynd, P. J. Weimer, W. H. van Zyl, and I. S. Pretorius, “Microbial cellulose utilization: fundamentals and biotechnology,” Microbiology and Molecular Biology Reviews, vol. 66, no. 3, pp. 506–577, 2002.
[5]
S. Ninawe and B. C. Kuhad, “Use of xylan-rich cost effective agro-residues in the production of xylanase by Streptomyces cyaneus SN32,” Journal of Applied Microbiology, vol. 99, no. 5, pp. 1141–1148, 2005.
[6]
N. Kulkarni, A. Shendye, and M. Rao, “Molecular and biotechnological aspects of xylanases,” FEMS Microbiology Reviews, vol. 23, no. 4, pp. 411–456, 1999.
[7]
H. A. E.-N. Nadia, M. M. El Sayed, G. S. Wafaa, and H. E. S. Gehad, “Purification and partial characterization of extracellular cellulase free xylanase from Streptomyces rochei,” Journal of Applied Sciences Research, vol. 6, no. 9, pp. 1373–1378, 2010.
[8]
D. Haltrich, B. Nidetzky, K. D. Kulbe, W. Steiner, and S. ？upan？i？, “Production of fungal xylanases,” Bioresource Technology, vol. 58, no. 2, pp. 137–161, 1996.
[9]
G. Narasimha, A. Sridevi, V. Buddolla, M. Subhosh Chandra, and B. Rajasekhar Reddy, “Nutrient effects on production of cellulolytic enzymes by Aspergillus niger,” African Journal of Biotechnology, vol. 5, no. 5, pp. 472–476, 2006.
[10]
L. F. Johnson and E. A. Curl, Methods for Research on the Ecology of Soil-Borne Plant Pathogens, Burgess Publishing Company, Minneapolis, Minn, USA, 1972.
[11]
J. L. Barnett and B. B. Hunter, Illustrated Genera of Imperfect Fungi, Burgess Publishing Company, Minneapolis, Minn, USA, 1972.
[12]
K. H. Domsch, W. Gams, and T.-H. Anderson, Compendium of Soil Fungi, vol. 1, Academic Press, London, UK, 1980.
[13]
E. Lieckfeldt, G. J. Samuels, H. I. Nirenberg, and O. Petrini, “A morphological and molecular perspective of Trichoderma viride: is it one or two species?” Applied and Environmental Microbiology, vol. 65, no. 6, pp. 2418–2428, 1999.
[14]
W. M. Jaklitsch, G. J. Samuels, S. L. Dodd, B.-S. Lu, and I. S. Druzhinina, “Hypocrea rufa/Trichoderma viride: a reassessment, and description of five closely related species with and without warted conidia,” Studies in Mycology, vol. 56, pp. 135–177, 2006.
[15]
M. K. L. Das, J. S. Prasad, and S. K. Ahmad, “Endoglucanase production by paper-degrading mycoflora,” Letters in Applied Microbiology, vol. 25, no. 5, pp. 313–315, 1997.
[16]
M. Mandels and J. Weber, “The production of cellulases,” Advances in Chemistry Series, vol. 95, pp. 394–414, 1969.
[17]
P. Fernandes Franco, H. Malheiros Ferreira, and E. X. Ferreira Filho, “Production and characterization of hemicellulase activities from Trichoderma harzianum strain T4,” Biotechnology and Applied Biochemistry, vol. 40, no. 3, pp. 255–259, 2004.
[18]
M. J. Bailey, P. Biely, and K. Poutanen, “Interlaboratory testing of methods for assay of xylanase activity,” Journal of Biotechnology, vol. 23, no. 3, pp. 257–270, 1992.
[19]
G. L. Miller, “Use of dinitrosalicylic acid reagent for determination of reducing sugar,” Analytical Chemistry, vol. 31, no. 3, pp. 426–428, 1959.
[20]
T. K. Ghose, “Measurement of cellulase activities,” Pure and Applied Chemistry, vol. 69, pp. 257–269, 1987.
[21]
O. H. Lowry, N. J. Rosebrough, A. L. Farr, and R. J. Randall, “Protein measurement with the Folin phenol reagent,” The Journal of Biological Chemistry, vol. 193, no. 1, pp. 265–275, 1951.
[22]
H. Qiao, C. Tian, Y. Luo, J. Sun, and X. Feng, “Diversity of soil microorganisms in natural Populus euphratica forests in Xinjiang, northwestern China,” Frontiers of Forestry in China, vol. 3, no. 3, pp. 347–351, 2008.
[23]
R. Jaime-Garcia and P. J. Cotty, “Crop rotation and soil temperature influence the community structure of Aspergillus flavus in soil,” Soil Biology and Biochemistry, vol. 42, no. 10, pp. 1842–1847, 2010.
[24]
H. Kausar, M. Sariah, H. Mohd Saud, M. Zahangir Alam, and M. Razi Ismail, “Development of compatible lignocellulolytic fungal consortium for rapid composting of rice straw,” International Biodeterioration and Biodegradation, vol. 64, no. 7, pp. 594–600, 2010.
[25]
P. Reanprayoon and W. Pathomsiriwong, “Tropical soil fungi producing cellulase and related enzymes in biodegradation,” Journal of Applied Sciences, vol. 12, pp. 1909–1916, 2012.
[26]
S. P. Gautam, P. S. Bundela, A. K. Pandey, J. Jamaluddin, M. K. Awasthi, and S. Sarsaiya, “Diversity of cellulolytic microbes and the biodegradation of municipal solid waste by a potential strain,” International Journal of Microbiology, vol. 2012, Article ID 325907, 12 pages, 2012.
[27]
K. Vega, G. K. Villena, V. H. Sarmiento, Y. Ludena, N. Vera, and M. Gutierrez-Correa, “Production of alkaline cellulase by fungi isolated from an undisturbed rain forest of peru,” Biotechnology Reseach Journal, vol. 2012, Article ID 934325, 7 pages, 2012.
[28]
R. P. De Vries and J. Visser, “Aspergillus enzymes involved in degradation of plant cell wall polysaccharides,” Microbiology and Molecular Biology Reviews, vol. 65, no. 4, pp. 497–522, 2001.
[29]
M. Yalpani, “Development and prospect in enzymatic biopolymer modification,” in Industrial Polysaccharide, vol. 3, Elsevier, 1987.
[30]
S. Nwodo-Chinedu, V. I. Okochi, H. A. Smith, and O. Omidiji, “Ioslation of cellulolytic microfungi involved in wood waste decomposition: prospects for enzymatic hydrolysis of cellulosic waste,” International Journal of Biomedical and Health Sciences, vol. 1, no. 2, 2005.
[31]
A. Sri Laksmi and G. Narasimha, “Production of cellulases by fungal cultures isolated from forest litter,” Annals of Forest Research, vol. 55, pp. 85–92, 2012.
[32]
K. Chandel, S. Jandaik, V. Kumari et al., “Isolation, purification and screening of cellulolytic fungi from mushroom compost for production of enzyme (cellulose),” International Journal of Current Research, vol. 5, pp. 222–229, 2013.
[33]
I. Khokhar, M. S. Haider, S. Mushtaq, and I. Mukhtar, “Isolation and screening of highly cellulolytic filamentous fungi,” Scholarly Journal of Agricultural Science, vol. 2, pp. 126–129, 2012.
