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Xylanase and Cellulase production by a termite associated Xyiaria species

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dc.contributor.advisor Gessesse, Amare(PhD)
dc.contributor.author Degefu, Tulu
dc.date.accessioned 2018-07-31T07:06:15Z
dc.date.available 2018-07-31T07:06:15Z
dc.date.issued 2006-08
dc.identifier.uri http://etd.aau.edu.et/handle/123456789/10598
dc.description.abstract Xyalaria sp. are known to be associated with termites. However, the benefit the termites get from this association is not yet known. Termites collect wood pieces from the surrounding and collect it in the mound. The wood is then converted to soft spongy mass, called comb. The comb is normally invaded with fungal mycelia. It is well known that termites use cellulose as energy source after degradation to glucose with the help of microbial cellulases in the gut. But lignified celluloses can not be digested by cellulases. We hypothesize that the fungus probably helps to delignify cellulose fiber either directly through lignin degradation or through removal of the hemicellulose that cement the lignin to the cellulose fiber. To test this hypothesis we collected termite comb from Zuway and extracted proteins. The extract showed high xylanase activity (24U/g comb) and no detectable cellulase activity. This indicates that the role of the fungus is probably to remove lignin from the cellulose fiber. The fact that there was no detectable cellulase in the comb indicates that the fungus and the termite are not competing for cellulose. The fungus was isolated from the comb in pure culture. It was then grown m culture usmg submerged fermentation (SmF) and solid·state fermentation (SSF). However, enzyme production in SSF was much higher than in SmF. Maximum enzyme production in SSF using wheat bran was obtained at a substrate to moisture level ratio of 1:0.5 to 1:2. Addition of different sugars to the SSF substrate didn't affect enzyme production, indicating that enzyme production is probably constitutive. The xylanase was optimally active in the pH range of 4 to 6 and at temperature of 40°c. These properties make Xylaria xylanase potentially attractive as animal feed supplements. Key words: Xylaria, Xylanase, Cellulase, Termites en_US
dc.language.iso en en_US
dc.publisher Addis Ababa University en_US
dc.subject Xylaria en_US
dc.subject Xylanase en_US
dc.subject Cellulase en_US
dc.subject Termites en_US
dc.title Xylanase and Cellulase production by a termite associated Xyiaria species en_US
dc.type Thesis en_US


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