Browsing by Author "Abraha, Berhanu"

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    The Effect of Some Physico-chemical Factors on the Production and Activity of Cellulase and B-Glucosidase from Cladosporium SP . BDCC-3
    (Addis Ababa,University, 1990-06) Abraha, Berhanu; A. Gashe, Berhanu (PhD)
    Conditions for the produC"tion, rele8se ... nd ... ctivi. y ot cellulases and B-Glucosidase tro", (11'1"os orium sp. »OCC:-J were investig8 ed. Comparisons !IIade- betwPt"n different carbon !'Iource-s lind their concenTrations for maxi1!lum prorlu~tjon of cellulas8s and aGlucosidase depicted 1 CHC 0.5' Avicel. 1.5'd.-c-I'11ulose. 0.5' filter paper .. nd 0 . 5 cotton to be op timum. From the nitrogen sources used . potassium nitr ate was found to be the nost utilizable by Clados orium 5p. BDCC-J. The OPti~um conce ntrations of nitrate for maximum production of the enzy~p.s were 1'. 1%. 2%. 2% and 1% i n CHC. Avical . -.. -cellulose . filter paper and cotton containing media. r espectively. The most appropri ate de terQent for the release of cellulases and B- Glucosidase was O.J Tween-SO . The enzymes had a wide range of pH . However . t hey were most active at pH 5.0 and 60°C. All enzymes l os t activity when i n cubate~ at 700C for 2 hours. Thus five different optimized media were f ormulated. These were:- 1. Optimized CMe medium 2 (OCI'1-2) containing 1" CHC. 1% KNO) and 0.1% Tween - 80 plus the basal medium 2 . Optimized Av icel medium 2(0 ~M -2) conta ining 0 .5" Avicel. 1% KNOJ and 0.1" Tween - 80 plus the basal medium. J . Optimized .. -Cellulose medium '-(0':' H-2 ) containing 1 . 5% ~ -Cellulose. 2% KNO) and 0.1% Tween - 80 plus the basal medium . 4 . Optimized filter paper medium 2(OFM-2) containinq 0.5% FP . 2 KNO) and 0.1 Tween - 80 plu~ the baSAl medium . 5. Optimized cotton medium 2(OCOH - 2) con t a ining 0.5 cotton. 1% KNOJ and 0.1% Tween - SO plus thp basal medium . The fungus produced maximum level o f CMC - al'le . Avicelase and ~~ -cell usl ese after 6 days o f incubAti on while Fp- asp, co t tonase and .a-Glucosidase were produced J to 6 d~ys later. Cl adosporium sp . BDCC- J produced Cx (cmc-8s e ) much hi.ghpr than CI ( ~v ice'8 s e . ~-'7 - cellulase. FP-ase . cottonase) and R-Glucosidase. A comparative study of free . cytoplasmic and membrane bound enzymes showed that cellulases were extracellular while a-Glucosidase was CytoplAsmic .