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Title: Xylanase production by the termite associated fungus, Termitomyces sp. and its role in the termite nest
Authors: Jemaneh, Zeleke
Keywords: Termitomyces sp
Termite Comb
Date Added: 21-Sep-2007
Abstract: A xylanase producing symbiotic fungus Termitomyces sp. was isolated from the termite mound around Nazareth found in Rift Valley area of Ethiopia. The culture was prepared from sporodochia found on the termite comb. Termitomyces sp. was slow grower (4.2cm in 2 weeks) than another termite associated fungal sp. Xylaria (9 cm/10 days). 405μg reducing sugar, 8.27U xylanase, 1.56% total nitrogen and 29.4mg soluble protein were analyzed in one gram of comb. pH and moisture content of the comb were 4.5 and 52.7% respectively. Termitomyces sp. produced xylanase more (42.2U/g) in SSF using wheat bran as carbon source than SmF (0.007U/ml) on xylan medium. The fungus produced xylanase on wheat bran, termite comb, wheat straw, bean straw and sugar cane bagasse using SSF. At 58% moisture level and 10 days of incubation, the highest level of xylanase produced on termite comb (52.24U/g) followed by wheat bran (37.37). No growth was observed on Avicell on SSF and CMC in SmF. Comb extract and yeast extract enhances enzyme production by 27.2% and 22% respectively, but xylose, glucose, sucrose, and lactose strongly repressed the enzyme production. The xylanase exhibited maximum activity at 55-600C and at pH 5.5, but it retained more than 85% of its activity in the pH range 4.5-6.5. The enzyme was stable up to 550C for 30 minutes incubation. Termitomyces xylanase was stimulated by Zn2+. However, it was inhibited by Mn2+, Fe3+, and Cu2+. Those properties make this enzyme potentially attractive for industrial applications like animal feed supplement and biopulping of wood.
Description: A Thesis submitted to the School of Graduate Studies of Addis Ababa University in Partial fulfillment of the Requirement for the Degree of Master of Science in Biology (Applied Microbiology)
URI: http://hdl.handle.net/123456789/139
Appears in:Thesis - Biology

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