【作者】 李英；

【导师】 宗浩；

【作者基本信息】 四川师范大学 ， 细胞生物学， 2005， 硕士

【摘要】 用以新华滤纸为唯一碳源的选择培养基从土壤、垃圾中初筛到24株产纤维素酶且生长旺盛的细菌,采用刚果红鉴别培养基作进一步识别,获得透明圈较大的菌株6株。在此基础上,进行液体培养,测定酶活,得到1株酶活较高的菌株,定名为ST-3。并对其进行了鉴定,归属为纤维单胞菌属（Cellulomonas）。 对ST-3菌产酶条件进行研究,结果表明:37℃是该菌产酶的最适温度,接种培养24h的菌液于液体发酵培养基中,产酶效果最好。麸皮能够较大幅度促进产酶,有机氮促进产酶的效果优于无机氮,最优的氮源是牛肉膏。用正交实验对产酶条件进行了优化,确定了最优培养基的组成。在最优条件下进行发酵,CMCase的最适产酶时间为22h,FPA为16h。 ST-3所产生的纤维素酶,CMCase作用的最适温度为50℃,最适反应pH值为4.0。FPA作用的最适温度为55℃,最适反应pH值为5.0。无论是CMCase还是FPA,Co²⁺都能显著激活酶活性,Hg²⁺、Ag²⁺、Mn²⁺对酶则有显著的抑制作用。 通过ST-3菌分解纤维素类废弃物和降解垃圾的实验表明,ST-3菌能使以玉米秸杆、小麦秸杆、水稻秸杆、麸皮、菌渣为碳源的发酵培养液中还原糖显著增加,说明该菌能充分降解玉米秸杆、小麦秸杆、水稻秸杆、麸皮、菌渣。其中,对玉米秸杆、麸皮的作用最为明显。对垃圾也能起到一定的降解作用。这对于解决我国当前的环境污染和能源危机都有重要意义。因此,ST-3菌具有一定的应用价值。更多还原

【Abstract】 24 cellulose-decomposing bacteria were isolated from soil and rubbish compost by selective liquid medium with xinhua filter paper as the sole carbon source. We got six colonies surrounded by some distinct zones of clearing in cellulose-congo red ag-ar medium. By measuring the enzyme activity of liquid culture filtrates, we got a strain with higher cell-ulase activity.It was named ST-3 and identified as Cellomonas.The fermentation conditions in shaking flasks were investigated. The highest level of cellulose activity was induced in the mendium containing wheat bran.The efficiency of organic nitrogen sources was better than that of inorganic nitrogen sources, while beef extract was the best organic nitrogen source. The components of the medium were optimized by the method of orthogonal experiment, when ST-3 was cultured under the optimum conditions, the optimal time for CMCase and FPA was 22h and 16h.Properties of cellulose from ST-3 were stuied. The results showed that the optimum temperature and pH for CMCase was 50℃ and 4.0, respectively; FPA was 55℃ and 5. 0. For CMCase and FPA, Co2+ could significantlypromote enzyme activity, while Hg2+、 Ag2+、 Mn2+ could restrain enzyme activity.The experiment that decomposing the cellulose waste and rubbish compost by ST-3 showed that the soluble reducing sugar could be increased significantly in the liquid medium with corn straw、 wheat straw、 rice straw、wheat bran and edible mushroom waste respectivly as the sole carbon source. It proved that ST-3 could decompose them, especially for corn straw and wheat bran.To some degree ST-3 could decompose rubbish compost. It is impotent to solve the environment pollution and energy crisis. Therefore, ST-3 has the utilization value to some extent.更多还原