| 摘要: |
| 【目的】研究不同条件下复合菌系的秸秆分解能力和酶活性，评价该复合菌系的功能稳定性及适应性，为进一步完善该复合菌系的筛选技术及其应用提供理论依据。【方法】以复合菌系GF-20为研究对象，在不同温度和pH值条件下连续继代培养，测定所得复合菌系的滤纸分解特性、玉米秸秆降解率、发酵液pH 值、纤维素酶和半纤维素酶活性，以评价复合菌系的功能稳定性。【结果】在温度4～30 ℃、pH 6.0～9.0时，经过15代的继代培养，复合菌系GF-20在培养的108～140 h可分解滤纸纤维素，玉米秸秆降解率保持在30%以上，发酵液pH值随发酵时间的延长趋近于中性， pH 调节能力良好，纤维素酶活性为1.22～2.34 U/mL，半纤维素酶活性为12.82～14.23 U/mL。【结论】复合菌系GF-20可在较大的温度和pH范围内保持较高的纤维素和半纤维素酶活性，能发挥秸秆降解作用，具有良好的开发潜力和应用前景。 |
| 关键词: 玉米秸秆 复合菌系GF-20 纤维素分解 纤维素酶活性 pH适应性 |
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| 基金项目:国家科技支撑计划项目（2011BAD16B13，2012BAD04B04，2013BAD07B04）；国家玉米产业技术体系项目（CARS-02-63）；内蒙古农业大学引进人才科研启动基金项目（YJ 2014-5） |
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| Effect of temperature and pH on the stability of a composite microbial system GF-20 for efficient degradation of corn stalk at low temperature |
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Qinggeer,GAO Julin,YU Xiaofang,et al
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| Abstract: |
| 【Objective】This study analyzed the straw decomposition and enzyme activities of composite strains under different conditions and evaluated the function stability and applicability to help develop screening methods and applications.【Method】With composite microbial system GF-20 as the object,continuous subcultures under different temperatures and pH were conducted,and decomposition of filter paper,corn stalk degradation ratio,pH value,cellulose and xylanase enzyme activities were measured to evaluate stability of the composite microbial system.【Result】At the temperature of 4-30 ℃ and pH of 6.0-9.0,the microbial community GF-20 could decompose cellulose filter paper in 108-140 h with corn straw degradation rate of higher than 30% after 15 generations of successive culturing.The pH value tended to be neutral with the increase of fermentation time and the system had good pH adjusting ability.The cellulase and xylanase activities ranged in 1.22-2.34 U/mL and 12.82-14.23 U/mL.【Conclusion】The composite microbial community GF-20 would maintain high cellulose enzyme activities and degradation ability over a wide range of temperature and pH,and it has good application prospect. |
| Key words: corn stalk composite microbial community GF-20 decomposition of filter paper cellulase activity pH stability |
