• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.45-51
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• 1989

A major problem in the enzymatic hydrolysis of lignocellulosic substrates is the very strong bonding of cellulase to lignin and even cellulose in the hydrolysis residues. This phenomenon inhibits recycle of the cellulase which is a major expense of the enzymatic hydrolysis process. In this paper, autohydrolyzed wood was delignified by two-stage with a 0.3% Na OH extraction and oxygen-alkali bleaching and was subjected to enzymatic hydrolysis with cellulase. Also, an improved almost quantitative recycle process of cellulase enzyme was discussed. In enzyme recovery by affinity method. the first recycling showed relatively high hydrolysis rate of 97.4%. Even at the third recycle. hydrolysis rate was 86.7 percents. In the case of cellulase recovery by ultrafiltration method, first 2 recycling treatments resulted very high hydrolysis rate(97.0-97.7%). Even the third recycling showed about 94.2%. Authoydrolysis of oak wood followed by 2-stage delignification with alkali and oxygen-alkali produced a substrate for enzymatic hydrolysis that allowed almost quantitative recycle of cellulase.

• Journal of the Korean Wood Science and Technology
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• v.19 no.1
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• pp.14-21
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• 1991

Steam-exploded woods were delignified by two-stage with a 0.3% NaOH extraction and oxygen-alkali bleaching and were subjected to the enzymatic hydrolysis with cellulase enzyme. Also, an improved almost quantitative recycle process of cellulase enzyme was discussed. In enzyme recovery by affinity method, The first recycling showed relatively high hydrolysis rate of 96.4%. Even at the third recycle, hydrolysis rate was 87.0 percents. In the case of cellulase recovery by ultrafiltration method, first 2 recycling treatments resulted in very high hydrolysis rates, 96.8% and 95.0%, respectively. Even the third recycling showed about 93.6%. Steam-explosion treatment of oak wood followed by 2-stage delignification with alkali and oxygen-alkali produced a excellant substrate for the enzymatic hydrolysis that allowed almost quantitative recycle of cellulase.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.268-274
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• 2002

Enzymatic hydrolysis of waste office paper was evaluated using three commercial cellulases, Acremonium cellulase, Meicelase, and Cellulosin T2. Varying the enzyme loading from 1 to 10% (w/w) conversion of waste office paper to reducing sugar was investigated. The conversion increased with the increase in the enzyme loading: in the case of enzyme loading of 10% (w/w), Acremonium cellulase yielded 79%conversion of waste office paper, which was 17% higher compared to Meicelase, 13% higher than that of Cellulosin T2. Empirical model for the conversion (%) of waste office paper to re-ducing sugar (x) was derived from experimental results as follow, x = $kE^{m}t^{(aE+b)}$ where k, m, a, and b de-note empirical constants. E indicates initial enzyme concentration.

• Journal of Forest and Environmental Science
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• v.37 no.1
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• pp.52-61
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• 2021

Decay fungi can decompose plant debris to recycle carbon in the ecosystem. Still, they can also be fungal pathogens, which can damage living trees and/or wood material and cause a large amount of timber loss. We isolated and identified basidiomycetous fungi from the decayed bark of Mongolian oak wrapped with sticky roll traps. The degrading enzyme activities were then tested for all fungal isolates. The decay ability of selected isolates was assessed based on the weight loss of wood discs after inoculating with culture suspension of decay fungi under the different humidity levels. A total of 46 basidiomycetous fungal isolates belonged to 12 species, and 10 genera were obtained from Jong Myo (16 isolates), Chang Kyung palace (7 isolates), Cheong Gye (10 isolates), and Gun Po (13 isolates). Gymnopus luxurians was the most dominant fungus in the present study, and this species distributed in all survey sites with 9 isolates in Jong Myo, followed by 3 isolates in Chang Kyung palace, while Cheong Gye and Gun Po had only 1 isolate each. Among 46 isolates, 44 isolates secreted at least one enzyme, while 25 isolates produced both cellulase and phenol oxidase enzymes, and 2 isolates produced neither. The assessment of decay ability by artificial inoculation indicated that the weight loss of wood discs was significantly influenced by humidity conditions when inoculated with bark decay fungi. The percent weight losses by G. luxurians inoculation in RH of 90-100% and RH of 65-75% were 4.61% and 2.45%, respectively. The weight loss caused by Abortiporus biennis were 6.67% and 0.46% in RH of 90-100% and RH of 45-55%, respectively. The humidity reduction approach should be applied for further studies to control the growth and spread of bark decay fungi on the trunks wrapped with sticky roll traps.