Some properties of a crude cellulosic enzyme from Aspergillus niger ATCC 6275 cultivated on palm cake
สมบัติบางประการของเอนไซม์จาก Aspergillus niger ATCC 6275 ที่เลี้ยงบนกากปาล์ม
Saowaluck Jitbunjerdkul, Asst. Prof., D. of Food Tech., F. of Agro-Industry, PSU.
Susumu Oi, Prof., Microbiological Chemistry Laboratory, F. of Sci., Osaka City U., Osaka, Japan
Corresponding e-mail : jsaowalu@ratree.psu.ac.th
Grant : JSPS
Published : Songklanakarin J Sci Technol 2000, 22(2) : 235-240
Key words : palm cake, palm waste, cellulase, enzymatic hydrolysis,
crude enzyme preparation
The properties of a crude enzyme preparation from Aspergillus niger ATCC 6275 cultivated
on palm cake were investigated. The carboxymethyl cellulase (CMCase) had an optimum pH of 3.5, whereas the xylanase and b-glucosidase showed an optimum pH of 4.0. Optimum temperature of the CMCase, xylanase and b-glucosidase activities was 55, 50 and 60oC, respectively. Thermal stability of the crude enzyme was up to 40oC for 1 h. At temperatures of 70oC and 75oC, CMCase of the crude enzyme showed a relative activity of about 27% and 15%, respectively. About 3% of the b-glucosi-dase activity was retained above 70oC. The crude enzyme preparation was used for hydrolysis of palm cake and two commercial substrates (cellulose powder and CMC). It was found that the crude enzyme from Aspergillus niger ATCC 6275 was most active on CMC and the hydrolysis extent was 63% as reducing sugar.
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