台湾假单胞菌的分离、鉴定及其对难溶性磷酸盐的溶解特性

Isolation, identification of Pseudomonas taiwanesis and its bio-solubilization of insoluble phosphates

为了获得能高效转化土壤中难溶性磷酸盐的溶磷微生物,从武汉市园林科学研究所里的车前草根际土样中,根据溶磷圈的大小筛选出一株溶磷能力较强的细菌P2。经形态学、生理生化特征和系统进化分析,确定菌株P2归属于台湾假单胞菌(Pseudomonas taiwanensis)。经条件优化后,菌株P2溶解磷酸三钙的最大溶磷量(以PO 3-4计)可达到1267.89 mg/L,约为优化前的1.43倍。菌株P2对磷酸氢钙、羟基磷灰石、磷酸铝、磷酸铁和磷矿粉也有不同程度的溶解,溶磷量分别达到1752.58、1644.33、67.01、46.39、72.16 mg/L。高效液相色谱分析显示磷的溶出率与培养液中总有机酸浓度之间存在正相关性。菌株P2可明显提高土壤中的有效磷含量,具有良好的微生物肥料应用前景。

In order to find phosphorous-solubilizing microorganisms that can efficiently convert insoluble phosphates in soils,a strain named as P2 with better phosphorus-solubilizing ability was obtained from soil samples collected from the rhizosphere of plantain in Wuhan Institute of Landscape Science according to the diameters of solubilization halos in NBRIP medium.The morphology,physiological and biochemical characteristics,phylogenetic analysis based on 16S rDNA gene sequence show that Strain P2 falls into Pseudomonas taiwanensis.The highest soluble phosphate(PO 3-4)content of Ca 3(PO 4)2 dissolved by P2 under the optimal conditions is 1267.89 mg/L,about 1.43 times of that under non-optimized conditions.Strain P2 can also release soluble phosphorous from CaHPO 4,hydroxyapatite,AlPO 4,FePO 4 and ground phosphate rock,with the concentration of dissolved PO 3-4(mg/L)at 1752.58,1644.33,67.01,46.39 and 72.16,respectively.High performance liquid chromatography analysis points to a positive correlation between P-dissolution rate and the production of organic acids in the medium.Strain P2 obviously increases the content of available phosphorus in soil and could be a promising microbial fertilizer.