厌氧分解纤维素细菌P4-3的产酶特性及其纤维小体组分的定位

Enzyme Production Characteristics of Anaerobic Cellulolytic Bacteria Strain P4-3 and the Location of Cellulosome Components

中温厌氧纤维素分解菌P4-3可产生活性较高、热稳定性较强的纤维素酶。通过检测CMC酶活性,研究了培养时间、温度、培养基初始pH值、碳源和氮源对其产酶的影响。通过破壁处理,检测不同部位粗酶液中的CMC酶、滤纸酶及β-葡萄糖苷酶活性,分析了其纤维小体中三种酶组分的分布和比例。结果显示,利用滤纸和纤维二糖作为底物达到最大酶活的时间分别为144 h和72 h;产酶最佳温度为40℃,pH值为7.5,纤维二糖为最佳碳源,酵母粉为最佳氮源。培养144 h,CMC酶、滤纸酶及β-葡萄糖苷酶在上清液、未破壁菌体悬浮液与破壁菌体悬浮液中的活性比分别为9∶1∶1,14∶4∶3和6∶3∶4。

Mesophilic anaerobic ceUulolytic bacterium strain P4-3 could produce high active and thermal stable cellulase. Effects of culturing period, temperature, initial pH, carbon sources and nitrogen sources on cellulase production of strain P4-3 were analized by detecting the CMCase activity. The activities of CMCase, FPA, and β-glucosidase in crude enzyme solution from supernatant, membrane, and broken cell suspension were determined. Proportion and distribution of cellulo-some components in cultures were analyzed. The results indicated that the maximum ceUulase activity of strain P4-3 appeared after 144 h of culturing with filter paper as substrate, and 72 h with cellobiose as substrate. The optimal temperature, pH, carbon source and nitrogen source for CMCase production were 40℃,pH 7.5, eellobiose and yeast extract. After culturing 144 h, the proportions of CMCase, FPA and β-glucosidase in supernatant, membrane, and broken cell suspension were 9： 1： 1,14： 4：3 and 6： 3： 4, respectively.