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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|
|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)|
|Appears in:||Thesis - Biology|
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