解淀粉芽孢杆菌YP6中碱性磷酸酯酶AP3的酶学性质及其溶磷作用

Characterization of a phosphorus-solubilizing alkaline phosphatase AP3 cloned from Bacillus amyloliquefaciens YP6

摘要:

【背景】微生物溶磷机制多种多样，利用其解磷能力可有效促进植物生长。【目的】探究溶磷菌解淀粉芽孢杆菌YP6的溶磷机制，提高磷资源的利用率。【方法】在大肠杆菌BL21(DE3)中克隆并表达YP6中磷酸酯酶AP3基因，研究AP3的酶学性质并验证AP3的溶磷作用。【结果】AP3为碱性磷酸酯酶，最适反应pH为10.3，最适反应温度为40 °C，AP3对pNPP亲和性较高，Vm为4 033.4 μmol/(min·mg)，Km为12.2 mmol/L。用纯酶AP3处理24 h后，磷矿粉中的有效磷显著增加。接种菌株YP6发酵7 d后，也使土样中有效磷明显增长。【结论】揭示了碱性磷酸酯酶AP3的溶磷能力，丰富了溶磷微生物库及对微生物溶磷机制的认识。

Abstract:

[Background] The mechanisms of solubilizing-phosphorus by organisms are diverse, which significantly stimulates plant growths. [Objective] To characterize a phosphorus-solubilizing alkaline phosphatase from Bacillus amyloliquefaciens YP6. [Methods] An alkaline phosphatase, AP3, of YP6 was cloned, expressed in Escherichia coli BL21(DE3), characterized and its phosphorus-solubilizing effect tested. [Results] AP3 was an alkaline phosphatase, with optimal pH at 10.3 and optimal temperature at 40 °C. Vm was 4 033.4 μmol/(min·mg) and Km was 12.2 mmol/L. The soluble phosphate of rock phosphorus was enhanced obviously by enzyme AP3 treatment for 24 h, and by inoculation of the strain Bacillus amyloliquefaciens YP6 for 7 days. [Conclusion] Alkaline phosphatase AP3 can be used as a phosphorus-solubilizing enzyme.