Production and Mode of Action of Novel Endoglucanase Disintegrating Native Cellulose

Avicel可吸附的内切葡聚糖酶(MW.128,000)和Avicel不可吸附的内切葡聚糖酶(MW.经凝胶过滤和离子交换层析，从突变株140号和突变株191号的培养滤液中分离纯化出63,000个菌株。两种酶均能适应不同的pH和温度，并能迅速降低CM-纤维素的粘度。Avicel可吸附的内切葡聚糖酶具有较强的滤纸裂解活性，并与里氏木霉纤维素酶制剂在降解微晶纤维素方面具有很强的协同效应。这种内切葡聚糖酶通过扫描电子显微镜观察，从表面一层又一层地分解Avicel原纤维，产生带有裸露链端的薄片。Avicel不可吸附的内切葡聚糖酶对滤纸和Avicel没有解离活性，与里氏木霉纤维素酶在降解微晶纤维素方面的协同作用不如前者。因此，内切葡聚糖酶分为两种类型，即Avicel-崩解和-非崩解。

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.