Production and Mode of Action of Novel Endoglucanase Disintegrating Native Cellulose

Avicel可吸附内切葡聚糖酶（MW. 128，000）和Avicel-不可吸附的内切葡聚糖酶（MW.用凝胶过滤和离子交换层析从突变体140号和突变体191号的培养物中纯化得到63，000）。这两种酶对pH和温度都很稳定，能迅速降低CM-纤维素的粘度。Avicel可吸附内切葡聚糖酶具有较强的滤纸粉碎活性，并与里氏木霉纤维素酶制剂在微晶纤维素的水解中表现出较强的协同作用。通过扫描电子显微镜观察到这种内切葡聚糖酶从表面一层一层地分解Avicel原纤维，产生具有暴露的链端的薄切片。Avicel非吸附性内切葡聚糖酶对滤纸和Avicel无崩解活性，与T. reesei纤维素酶水解微晶纤维素的能力优于前者。因此，内切葡聚糖酶分为两种类型，Avicel崩解型和非崩解型。

The Avicel-adsorbable endoglucanase (MW. 128,000) and the Avicel-unadsorbable endoglucanase (MW. 63,000) were purified from the culture filtrates of mutant No. 140 and mutant no.191, using gel filtration and ion exchange chromatography. Both enzymes were satble to varying pH and temperature and could rapidly decrease the viscosity of CM-cellulose. The Avicel-adsorbable endoglucanase showed intensive filter-paper-disintegrating activity and a highly synergistic effect with the cellulase Preparation of Trichoderma reesei in the hydrolysis of microcrystalline cellulose. This endoglucanase was observed via scanning electron microscopy to disintegrate Avicel fibrils layer by layer from the surface, yielding thin sections with exposed chain ends. The Avicel-unadsorbable endoglucanase showed no disintegrating activity on filter paper and Avicel and a less synergistic effect with the T. reesei cellulase in hydrolyzing microcrystalline cellulose than did the former enzyme. Endoglucanase was therefore divided into two types, Avicel-disintegrating and -nondisintegrating.