纤维素降解菌的筛选与复合菌系的初步构建

目的 针对大庆地区土地盐碱化较严重，盐碱面积较大等现状，从大庆特征性盐碱地区土壤样品中分离出能够降解纤维素的菌株，为降解植物废料以及缓解土壤盐碱化改善土壤环境提供功能菌株。方法 通过刚果红染色法初步筛得到具有纤维素降解能力菌株，进一步用比色法测定其纤维素降解率，同时测定菌株耐盐、耐碱、产酸性能，选择性能优良的3株菌作为纤维素降解菌复合菌系构建菌株，通过耐盐性、耐碱性和纤维素降解率实验测定复合菌系菌株最佳组合，进一步通过上述实验确定复合菌系菌株最佳混合比例。结果 得到由DX-5和DX-9按照2∶3进行组合复合菌系纤维素降解率最高，达到87.96%，且具有较高的耐盐以及耐碱能力。结论 通过实验得到纤维素降解菌的复合菌系，具有较高纤维素降解率以及改善土壤盐碱性能力。

Screening of cellulose degrading bacteria and preliminary construction of composite microbial system

Objective To isolate cellulose-degrading strains from the saline soil in Daqing and provide functional strains for remission of soil salinization and improvement of soil environment. Methods The celluse-degrading strains were preliminarily screened with Congo red staining method; their cellulose degradation rates were determined by colorimetry. The salt tolerance, alkali resistance and acid production of the strains were tested. Three strains were selected as the candidate strains to construct the composite microbial system, the optimal combination and proportion of which were determined through the detection of their salt tolerance, alkali resistance and cellulose degradation rates. Results The composite microbial system consisted of the strains DX-5 and DX-9 in the ratio of 2∶3 demonstrated a high cellulose degradation rate up to 87.96% with high tolerance to salt and alkali. Conclusion A composite microbial system of cellulose degradation was obtained, which had high cellulose degradation rate and the ability to relieve soil salinization.