内蒙古草原羊草根际联合固氮菌的分离鉴定及其生理生化特性研究

作者从内蒙古锡林郭勒草原优质牧草－羊草根际分离筛选出两株根际联合固氮菌。根据形态特征和生理生化特性，菌株Ａ－１属催娩克雷伯氏菌，菌株Ｂ－１８属肺炎克雷伯氏菌肺炎亚种。对其进行生理生化特性，培养特性，固氮酶活性，氧浓度对固氮酶活性影响等方面的研究。结果表明，菌株均在微好氧条件下固氮活性最高，在Ｈｉｌｌ无氮培养基上３０℃恒温培养，其固氮酶活性分别在１８和１６小时左右达到最高峰。

Isolation and Characteristics of N_2-fixers From Rhizosphere of Plant Leymus chinensis in the Rangeland of Inner Mongolia

Two strains with higher nitrogen-fixation activities among the six strains of N2fixers, have been isolated from the soil of Leymus chinensis rhizosphere in the grassland Inner mongolia. According to the characteristics of morphological character and physiobiochemistry of the strains, the strain A-1 belongs to the Klebsiella axytaca, the other one B-18 belongs to the Klebsiella pneumoniae subsp. pneumoniae. The two strains have higher nitrogenase activity under the condition of low pressure of oxygen.