纤维素分解菌的分离及产酶条件研究

Study on Isolation of Cellulose-decomposing Microorganisms and its Cellulase-producing Conditions

[目的]寻求最适宜的纤维素分解菌产酶条件。[方法]通过菌种筛选与鉴定试验,研究5种碳源(麸皮、滤纸、葡萄糖、蔗糖和CMC)、5种氮源(蛋白胨、硫酸铵、草酸铵、硝酸铵、柠檬酸)、培养时间、液体发酵培养基初始pH值和5个培养温度(22、263、03、4和38℃)对微生物产酶的影响。[结果]从土壤、牛粪样品中共分离出17株微生物菌株,其中1株T2菌丝密集,菌落在PDA培养基上生长快,经鉴定为木霉菌。T2菌株最适宜的产酶条件是:碳源为麸皮、羧甲基纤维素等纤维素物质、氮源为蛋白胨和硝酸铵、培养时间为3~4 h、液体发酵培养基初始pH值为4~6、培养温度为26~34℃。[结论]T2菌株在30℃下培养时,相应的滤纸酶活力、CMC酶活力最高值分别为10.72和47.52 U/g。

[Objective] The aim of this research was to seek for the optimum cellulase-producing conditions for cellulose-decomposing microorganisnisms. [Method] In the strain screening and identifying tests, the effect of 5 kinds of C resources （bran, filter paper, glucose and CMC）, 5 kinds of N resources （peptone, ammonium nitrate, an^nonium oxalate, ammonium nitrate and Citric acid）, culture time, initial pH of liquid fermentation medium and 5 culture temperatures （22, 26, 30, 34 and 38 ℃ ） on producing cellulase by microorganisms. [ Result] Seventeen strains of cellulose-decomposing microorganisms were isolated from cattle manures and soil, among which, T2 strain had dense mycelium, and its colony could grow faster on the PDA medium and it was identified as trichodenna. The optimum cellulase-producing conditions for T2 strain was follows： with the cellulose matters such as bran and CIVIC as the C and the peptone and ammonium nitrate as the N source, culture time of 3 -4 h, the initial pH of liquid fermentation medium in 4 - 6 and culture temperature of 26 - 34 ℃. [Conclusion] When T2 strain was cultured at 30℃, the highest enzyme activities with the filter paper and CMC as C resources could go up to 10.72 and 47.52 U/g,resp.