以選擇性溫度培養法（Selective temperature method），自土壤、稻草、落葉及堆肥中分離得嗜高溫及耐高溫真菌共12 種，其中6種具水解纖維素的能力，而以嗜熱毛殼菌（Chaetomium thermophije var. thermophile）之水解能力最強。若以濾紙做為碳源誘導嗜熱毛殼菌產生纖維素水解酵素，則第20天可測得較高之活性。酵素作用之最適酸鹼值（pH）及溫度分別為：CMCase: pH6, 65℃; Avicelase: pH5.5, 55℃;β-glucosidase: pH5.5, 65℃及FPA: pH5.5, 60℃。上述各酵素在30℃至60℃之間穩定性較佳，對pH值之穩定範圍為4 至7之間。將嗜熱毛殼菌與不分解濾紙的疏毛腐質黴（Humicola lanuginose）混合培養以後，測得濾紙之減少重量校單獨培養時多，而且酵素之活性亦有變化：如CMCase活性單獨培養大於混合培養，β-glucosidase 活性混合培養為單獨培養之5至10倍，而FPA活性混合培養大於單獨培養。以濾紙為水解基質時，單獨培養與混合培養之酵素水解產物皆為葡萄糖，然而以酸處理纖維素（Acid-swollen cellulose）為水解基質時，單獨培養之水解產物為葡萄糖及纖維貳糖（cellobiose），而混合培養之水解產物則為葡萄糖。纖維貳糖可誘導疏毛腐質黴產生β-glucosidase，而且，氮源對此誘導作用影響甚鉅。

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.