红树林土壤解磷菌的分离鉴定及解磷特性

从罗源湾红树林根际土壤中分离解磷菌，筛选出洋葱伯克霍尔德菌（Burkholderia cepacia， NR 113645.1）和短小芽孢杆菌（Bacillus pumilus， NR 043242.1），研究它们的解磷特性和动态解磷过程. HPLC结果表明， B. cepacia菌液上清中含葡萄糖酸、丙酮酸、乳酸、乙酸、丁二酸， 这些有机酸的产生导致磷酸盐溶解. B.pumilus菌液上清中仅检测到少量的葡萄糖酸， 因此该菌溶磷效果不佳. 在细菌动态溶磷过程中发现， 经B. cepacia菌处理的磷酸钙， 其X射线衍射（XRD）特征峰强度随时间的增长降低， 显微镜图像显示磷酸钙颗粒随时间增长变小， 甚至消失. 而经B.pumilus菌处理的结果表明， 在试验期间内磷酸钙峰强度和颗粒大小没有明显变化. 细菌产生有机酸是溶解磷酸盐的重要前提， 这是解决板结土壤中难溶性磷源转化为生物可利用磷源问题的关键.

Isolation and identification of phosphate-solubilizing bacteria from mangrove and their phosphate-solubilizing characteristics

The strains of Burkholderia cepacia (NR 113645.1) and Bacillus pumilus (NR 043242.1) were isolated from the mangrove rhizosphere soil of Luoyuan Bay. Their phosphate-decomposing characteristics and dynamic phosphorus-decomposing process were characterized. HPLC results showed that the supernatant of B. cepacia bacteria contained gluconic acid, pyruvate, lactic acid, acetic acid, and succinic acid. The production of these organic acids led to the dissolution of phosphate, resulting in that very little gluconic acid in supernatant and a bad phosphate-dissolving effect of B.pumilus. During the dynamic phosphorus dissolution of B. cepacia, The X-ray diffraction (XRD) characteristic peak intensity of calcium phosphate was dropped and the calcium phosphate particles became smaller or even disappeared with the prolonged treatment time. In contrast, XRD and microscope results showed there were no significant changes in the calcium phosphate's characteristic peak intensity and particle size when the same experiment was performed in B. pumilus. Dissolving phosphate is the key to solving the problem of converting insoluble phosphorus source into bioavailable phosphorus source in compacted soil.