不同微生物降解木质纤维素效率和过程的对比研究

Comparative study on the efficiency and process for lignin-degradation of different ligninolytic organisms

在固态秸秆上培养黑曲霉M1M15M19、黄孢原毛平革菌、杂色云芝和草菇VT53,优化营养条件和培养方式,测定秸秆降解过程中木质纤维酶类和秸秆成分的变化。结果表明,4菌株降解木质素的最佳碳氮比均为1 g秸秆中加入0.4 g葡萄糖和0.006 g氯化氨。单菌株降解时,黄孢原毛平革菌对木质素的降解效果最好,32 d固态培养后,木质素降解率为37.2%;多菌株联合降解时,先接黄孢原毛平革菌后接杂色云芝方式下的降解效果最好,32 d固态培养后,木质素降解率为51.3%;4株微生物都可产生漆酶(Laccase,Lac)、锰依赖过氧化物酶(Manganese-dependent peroxidase,MnP)、术质素过氧化物酶(Ligmin peroxidase,Lip)、纤维素酶(Cellulase,Cel)、半纤维素酶(Hemicellulase,Hcel)等木质素降解酶类(黑曲霉M1M15M19、黄孢原毛平革菌不产生Lac)。Lac、MnP、Lip是影响木质素降解的关键性酶类,Cel、Hcel是纤维素和半纤维素降解的关键性酶类,且酶活性越高,降解率越大。纤维素和半纤维素的降解优先于木质素;秸秆降解过程中产生还原性糖类,碳元素含量减少。研究表明,采用先接黄孢原毛平革菌后接杂色云芝的方式处理秸秆32 d时降解效果最好,可使木质纤维素发生生物高效降解。

The article is to introduce its author＇s comparative study on the efficiency and process for lignin-degradation of different ligni- nolytic organisms. In our study, we have cultivated 4 strains of lignin-degradation ligninolytie organisms （that is, Volvariella volvacea VT53 ; Phanerochaete chrysosporium ; Coriolus versicolor ; Aspergillus niger M1M15M19） on the solid straw by alone or double consociation with the purpose of optimizing nutrition condition and process of lignin-degradation. At the same time, we have also analyzed variations of main compositions in the straw and the activities of ligninolytic enzymes secreted by microbe. The results of our study have shown that it is the optimal carbon nitrogen ratio to add 0.4 g glucose and 0.006 g ammonium chloride to 1 g straw. In addition, Phanerochaete Chrysosporium proves to be the best one for lignin degradation by only one strain. 32 days solid-eulturation would help the rate of degradation to reach 37.2 % . On the other hand, the best way is to cultivate P. chrysosporium first and C. versicolor later by means of double strains＇ consociation, which can be expected to help the degradation rate of lignin to achieve 51.3% in the solid-cultivation 32 days later. Moreover, the strains can all secrete the ligninolytie enzymes, such as lacease, manganese-dependent peroxidase, lignin peroxidase, eellulase and hemicellulase in the process of lignin-degradation, which is crucial in affecting the biodegradation of lignin, cellulose and hemicellulose. Furthermore, the higher enzymatic activities, the higher biodegradation rate of the compositions of the straw. Thus, it can be concluded that biodegradation of cellulose and hcmicellulose proves to be superior to that of lignin. At the same time, some reducing sugar can also be produced with carbon reduced after the biodegradation.