Abstract: Inorganic phosphate-solubilizing bacteria were isolated from soil of five different alpine grassland types in the Eastern Qilian Mountains of the Qinghai-Tibetan Plateau,west of China.Physiological and biochemical characteristics were investigated to understand their potential utilization.Three phosphate-solubilizing bacteria strains and nitrogen fixation bacteria,wp1,wp2 and wp3 possess strong inorganic phosphorus solubility.Results also show that three bacteria have positive response to oxidase and catalase,but negative response to gelatin,nitrate reduction and V.P..The wp1 can use glutamic acid and extractum carnis on the tested nitrogen source,but wp2 cannot use cysteine and ammonia chloride.The wp3 can use glutamic acid,cystine and catalase.When pH>9,wp1 and wp3 grow declined,but wp2 grows well.Both wp2 and wp3 are tolerant to salt concentration in excess of 3% (NaCl),while wp1 is tolerant to 6% NaCl.

Key words: Alpine grasslands, Phosphate-solubilizing bacteria, Isolate, Physiological and biochemical characteristics

摘要： 使用传统的微生物分离培养法,对5种不同类型的高寒草地土壤中无机磷溶解菌进行了分离培养,并对优势溶磷细菌生理生化特征进行测定,以期为其开发利用提供依据。结果表明:从不同类型的高寒草地土壤中分离和筛选出28种固氮、溶磷细菌,其中wp1,wp2和wp3菌株溶磷能力较强,其氧化酶、接触酶反应均呈阳性,对明胶、硝酸还原和V.P.均呈阴性;对供试氮源wp1仅可以利用谷氨酸和牛肉膏,wp2不能利用胱氨酸和氯化铵,wp3可以利用谷氨酸、胱氨酸、牛肉膏;当pH>9时,wp3和wp1生长开始下降,wp2仍表现生长良好;当氯化钠浓度大于3%,wp2和wp3生长受到胁迫,大于6%时,wp1生长受到胁迫。

关键词: 高寒草地, 溶磷菌, 分离, 生理生化特征