解磷巨大芽孢杆菌(Bacillus megaterium)的溶磷机理探讨

Mechanism of Solubilizing Phosphate by Bacillus megaterium

从松辽平原玉米带中部的公主岭市贫磷黑土中分离筛选了1株具有较强溶磷能力的菌株,并通过16S rRNA基因测序鉴定为解磷巨大芽孢杆菌（Bacillus megaterium）。测定了溶磷圈和发酵液有效磷质量分数,探讨了菌株溶磷机理。结果表明：该菌株在以磷酸钙为唯一磷源的培养基上,能够形成明显的溶磷圈；发酵培养到第4天,发酵液的有效磷质量分数达到420 mg/kg。通过粒子大小分析仪,测定了溶磷菌发酵液中的磷酸钙颗粒大小,对照处理的磷酸钙粒径为132.7～181.7 nm,溶磷菌液处理的磷酸钙粒径为77.5～124.2nm,磷酸钙颗粒明显变小；通过高效液相色谱法（HPLC）和傅里叶变换红外光谱分析仪（FTIR）,对溶磷菌发酵液代谢产物进行分析,确定了溶磷菌最终的发酵产物为葡萄糖酸。

One strain of bacterium with strong phosphate solubilizing activity was isolated from phosphorus deficiency black soil samples in corn belt of the Songliao plain of Northeast China and identified as Bacillus megaterium by 16s rRNA gene sequencing. The soluble-P concentration continuously increased during the incubation periods and the total amount of soluble P released in culture filtrate was detected at 420 mg / kg after 4 days of inoculation. The particle size of calcium phosphorus surface was found to be destroyed and the size changed between 77. 5—124. 2 nm,while no changes in the surface and size were found in the control with the size of 132. 7—181. 7 nm. The metabolites of phosphate solubilizing bacteria fermentation broth were analyzed by high-performance liquid chromatograph（ HPLC） and Fourier transform infrared spectrometer（ FTIR） to determine the final fermentation products of phosphorus solubilizing bacteria for gluconic acid.