贺兰山东麓引黄灌区土壤中纤维素高效降解细菌的分离筛选

Isolation and Screening of Cellulose-degrading Bacteria in the Soil of Yellow River Irrigation Area at the Eastern Foot of Helan Mountain

为分离筛选出秸秆纤维素高效降解细菌,从而促进宁夏土壤微生物资源开发利用及水稻秸秆降解。本研究以宁夏贺兰山东麓银川平原引黄灌区杨树林下土壤为试材,利用羧甲基纤维素钠培养基对可培养微生物进行分离纯化,测定初筛细菌菌株羧甲基纤维素酶(CMCase)活性及滤纸最高酶活性,开展滤纸条崩解试验、秸秆崩解及降解率试验。结果表明:从土壤中分离纯化出127株细菌;其中纤维素降解能力较强的有13株;不同菌株D/d值、羧甲基纤维素最高酶活性、滤纸酶活性及滤纸条降解能力具有一定差异性,各指标的最大值均不是同一菌株。综合各项指标,确定菌株362、菌株225和菌株402可以用于水稻秸秆的高效降解。

In order to isolate and screen out bacteria which could degrade straw cellulose efficiently,so as to promote the development and utilization of soil microbial resources and rice straw degradation in Ningxia.In this study,the soil under poplar forest in the Yellow River Diversion Irrigation Area of Yinchuan Plain at the eastern foot of Helan Mountain in Ningxia was used as test material.The culturable microorganisms were isolated and purified by using sodium carboxymethyl cellulose medium.The activity of methyl cellulase(CMCase)and the highest enzyme activity of filter paper were determined.The filter paper disintegration experiment,straw disintegration and degradation rate experiment were carried out.The results showed that 127 strains of bacteria were isolated and purified from the soil,and 13 strains had strong cellulose degradation ability among them;the D/d values of different strains,the highest enzyme activity of carboxymethyl cellulose,filter paper enzyme activity and filter paper degradation ability were different,and the maximum values were not the same strain.In conclusion,the strains number of 362,225 and 402 can be used for effecient degradation of rice straw.