中文摘要：

复合菌系RXS能分泌多种木质纤维素降解酶,为探究这些酶在木薯渣降解中的作用,对RXS的培养时间、酶作用的温度和pH值,以及添加金属离子对酶活性和降解效果的影响进行了研究。结果表明,在培养48 h后,木聚糖酶（Xylanase）、滤纸酶（FPAase）和内切葡聚糖酶（CMCase）酶活性均达到最大值（分别为56.02 U/m L、3.14U/m L和6.78 U/m L）,pH=6.0（FPAase和Xylanase的最适pH值）、温度为55℃（FPAase和CMCase酶活性最高）条件下,RXS酶液处理可使木薯渣的失重率达到18.78%,纤维素和半纤维素质量分数分别由31.46%和20.19%下降到22.12%和12.23%。添加Cu~（2＋）有效地抑制了酶液中FPAase和Xylanase的酶活性,木薯渣几乎不降解,纤维素和半纤维素组分质量分数基本不发生变化;分别添加Co~（2＋）和Zn~（2＋）时,对3种酶均有一定程度的抑制,木薯渣失重率仅为3.29%和4.70%;分别添加Fe~（2＋）、Mg~（2＋）时,FPAase酶活性被抑制,Xylanase与CMCase共同降解底物,木薯渣失重率分别达12.77%和15.81%,纤维素和半纤维素质量分数明显降低。研究表明,Xylanase与CMCase是复合菌系中降解木薯渣的关键酶,其协同作用可使木薯渣有效降解。

英文摘要：

The paper is inclined to present the results of its investigation of the microbial consortium RXS,which can secrete a variety of lignocellulose degrading enzymes,mainly including cellulases and hemicellulases. In order to investigate the functions of the said enzymes in degradating the cassava residue,we have made detailed exploration of the cultivation time of RXS,the suitable temperature and pH value for the enzymatic activities,along with the functions of metal ions in the degradating process. The results of our study have shown that after 48 h of cultivation,it would be possible for the aforementioned FPAase,Xylanase and CMCase to reach their top levels of 3. 14 U/m L,56. 02 U/m L and 6. 78 U/m L,respectively,with pH value of 6. 0 being optimal for FPAase and Xylanase. On the other hand,it would be possible to find the greatest activity of FPAase and CMCase that may take place at the temperature of 55 ℃. 48 h,55 ℃ and pH = 6. 0 have been selected for the enzymatic reaction. At the same time,we have found that the weight-reduction rate of cassava residue prefers to take place is 18. 78%,whereas the content of cellulose and hemicelluloses tends to reduce from 31. 46% and20. 19% to 22. 12% and 12. 23%,respectively,after RXS secreted enzymes treatment. However,the effects of metal ions on FPAase,Xylanase and CMCase seem to be quite different. Furthermore,since Cu~（2＋）tends to inhibit FPAase and Xylanase activities effectively,with no degradation effects of cassava residue,and no variation of cellulose and hemicelluloses,which implies that CMCase activity may not be great enough for the lignocellulose hydrolysis. Co~（2＋）or Zn~（2＋）are in a position to inhibit the activities of the aforemetioned three enzymes to some extent,with the lower weight loss rate. However,Fe~（2＋）and Mg~（2＋）tend to inhibit FPAase,whereas the remaining Xylanase and CMCase tend to degrade the cassava residue effectively to a weight losing rate of cassava residue by 12. 77% and 15. 81%. In addition,the cellulos