Liu Wengan, He Yuanqiu, Zhang Kun, Fan Jianbo, Cao Hui
Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Wei Sheng Wu Xue Bao. 2012 Mar 4;52(3):326-33.
To improve use efficiency of phosphorus in latosolic red soil and to explore mechanism of phosphate solubilization.
Pikovskaya and National Botanical Research Institute' s Phosphate broth were used to isolate a phosphate-solubilizing bacterium coded as C5-A from the rhizosphere soil of peanut. According to its morphological, physiological, biochemical properties and its 16S rRNA sequence, its position in phylogenetic development tree was defined. By measuring changes in pH of the National Botanical Research Institute's Phosphate solution in which C5-A was incubated, phosphate solubilizing capacity was determined. Through fermentation, effects of carbon and nitrogen sources on the capacity of strain C5-A were investigated. Kinds and concentrations of organic acids in the cultures different in N sources were also determined by HPLC.
The strain was identified as Burkholderia cepacia, which is stable in hereditary. In aluminum phosphate and ferric phosphate solutions, its P solubilizing capacity was negatively related to pH. It solubilized tricalium phosphate, aluminum phosphate, ferric phosphate and rock phosphates powder, and could dissolve as much as 125.79 mg/L, 227.34 mg/L, 60.02 mg/L and 321.15 mg/L P, respectively. For RPP, P solubilizing capacity of the strain was related to type and concentration of the powder. When using maltose and ammonium oxalate as C and N sources, the strain displayed its highest P solubilizing capacity. HPLC analysis detected 10 organic acids in the culture, namely: oxalic acid, acetic acid, malic acid, lactic acid, citric acid, cuccinc acid and 5 unknown organic acids. Interestingly, it is acetic acid rather than gluconic acid being the most important organic acid affecting P solubilization.
The strain isolated from the rhizosphere soil of peanut plants growing in a red soil field can dissolve hard-to-solve inorganic salts, and is a promising microbial resource for development of high efficiency biological phosphorus fertilizer for latosolic red soil.
提高赤红壤中磷的利用效率，探究解磷机制。
采用皮氏（Pikovskaya）培养基和国家植物研究所磷酸盐培养基，从花生根际土壤中分离出一株编号为C5 - A的解磷细菌。根据其形态、生理生化特性及16S rRNA序列，确定其在系统发育树中的位置。通过测定C5 - A菌株培养的国家植物研究所磷酸盐溶液的pH变化，确定其解磷能力。通过发酵研究碳源和氮源对C5 - A菌株解磷能力的影响。采用高效液相色谱法（HPLC）测定不同氮源培养物中有机酸的种类和浓度。
该菌株鉴定为洋葱伯克霍尔德菌，遗传稳定性良好。在磷酸铝和磷酸铁溶液中，其解磷能力与pH呈负相关。它能溶解磷酸三钙、磷酸铝、磷酸铁和磷矿粉，溶解的磷量分别可达125.79 mg/L、227.34 mg/L、60.02 mg/L和321.15 mg/L。对于磷矿粉，该菌株的解磷能力与矿粉类型和浓度有关。当以麦芽糖和草酸铵作为碳源和氮源时，该菌株表现出最高的解磷能力。HPLC分析在培养物中检测到10种有机酸，即草酸、乙酸、苹果酸、乳酸、柠檬酸、琥珀酸和5种未知有机酸。有趣的是，影响磷溶解最重要的有机酸是乙酸而非葡萄糖酸。
从赤红壤田花生根际土壤中分离出的该菌株能溶解难溶性无机盐，是开发赤红壤高效生物磷肥的有潜力的微生物资源。
