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

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.

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

Mesophilic anaerobic cellulolytic 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 cellulosome components in cultures were analyzed.The results indicated that the maximum cellulase 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,cellobiose 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.