高效纤维素分解菌复合系的筛选构建及其对秸秆的分解特性

选以高温期的堆肥样品为材料，经过多代淘汰及不同系之间的组配，最终筛选构建了一组木质纤维素分解菌复合系，在分别以滤纸、脱脂棉、稻秸和锯末为碳源时，该复合系对天然纤维素含量高的滤纸和脱脂棉分解活性强，对纤维素含量较低、木质素含量相对高的锯末分解率最低。对稻秸的分解试验结果表明，该复合菌系在发酵初期对可溶性糖和淀粉的分解利用率远远高于对纤维素和半纤维素的分解，在整个发酵过程中，稻秸重量的变化与发酵液的pH变化有很大的一致性，发酵前5d内复合系对纤维素的分解活性最高。到发酵结束时，纤维素和半纤维素含量分别降低了7．39％和43．76％，而木质素在整个发酵过程中几乎不分解。

Selection and Construction of Composting Consortia for Degrading Lignocellulose Efficiently and Its Capability of Straw Degradation

A composite consortia with higher capacity of degrading lignocellulose were selected and constructed from different samples of high temperature stage in compost. It was obtained with the principle of compensation of acid and alkali, and by optimization and combination of different systems. The capability of cellulose degradation of microbial community was investigated with filter paper, absorbent cotton , rice straw and sawdust by the way of CMC-Na saccharogenic powder and gravimetry. The result showed that the composite microbial system could directly degrade carbon source with high native cellulose content (such as filter paper and cotton). By contrast that the degradation of sawdust was lower for it had higher content of lignin and lower cellulose. With the rice straw as the sole carbon source to test the degrading capacity, it showed that the microbial system could degrade dissolved sugar and starch more effectively than cellulose and hemicellulose at the initial stage of fermentation. In the first 3 days the content of dissolved sugar and starch reduced 58.5% and 30.44% respectively, and by the end of fermentation they reduced 72.91% and 47.85% respectively. During the whole period of fermentation, the changes of straw weight and pH of fermenting liquer are identical, and in the initial 5 days the microbial system has higher decomposing activity. By the end of fermentation, the contents of cellulose and hemicellulose reduced 7.39% and 43.76% respectively, while the lignin content had little change.