Isolation of Thermophilic Fungi and Celluiase Activity of Chaetomium Thermophile

• Main Author: 劉桂郁
• Other Authors: 簡秋源
• Format: Others
• Language: zh-TW
• Published: 1987
• Online Access: http://ndltd.ncl.edu.tw/handle/48660432414315603782

碩士 === 國立臺灣師範大學 === 生物學系 === 75 === 　　By using the selective temperature method, some of thermophilic and thermotolerant fungi were isolated fromvarious substrata, such as soil, straw, compost and leaf. The relative ability of these fungi to degrade cellulose was detected using an agar-diffusion method and chaetomium theunophile var. theunophile possessed the highest cellulolytic ability. The usage of filter paper as carbon source, C. theunophile produced extracellular cellulase. The optium pH values and temperatures for cellulase activity were: CMCase: pH 6.0, 65℃; Avicelase: pH 5.5, 55℃; β-glucosidase: pH 5.5, 65℃; FPA: pH5.5, 60℃.These enzymes were stable in the range pH 4-7 and 30℃-55℃. More decomposition of filter paper was caused by C. theunophile in combination with the non-cellulolytic Humicola lanuginosa than by C. theunophile alone. Mixed culture of C. theunophile and H. lanuginosa in liquid medium with filter paper produced cellulase which showed different activity from that of C. theunophile. β-glucosidase from mixed culture were five to tenfold over β-glucosidase from C. theunophile alone and FPA from mixed culture was higher than FPA from C. theunophile alone. with filter paper as substrate, the hydrolytic product of cellulase from mixed culture and C. theunophile alone was glucose. With acid-swollen cellulose as substrate, the hydrolytic product of cellulase from mixed culture was glucose and the hydrolytic products of cellulase from C. theunophile alone were cellobiose and glucose. The β-glucosidase synthesis of H. lanuginosa was induced by cellobiose and affected by ammonium nitrogen.