Behera B C, Yadav H, Singh S K, Mishra R R, Sethi B K, Dutta S K, Thatoi H N
Department of Biotechnology, North Orissa University, Baripada 757003, Odisha, India.
Department of Biotechnology, Birla Institute of Scientific Research, Statue Circle, Jaipur 302001, India.
J Genet Eng Biotechnol. 2017 Jun;15(1):169-178. doi: 10.1016/j.jgeb.2017.01.003. Epub 2017 Jan 21.
Phosphorus is an essential element for all life forms. Phosphate solubilizing bacteria are capable of converting phosphate into a bioavailable form through solubilization and mineralization processes. Hence in the present study a phosphate solubilizing bacterium, PSB-37, was isolated from mangrove soil of the Mahanadi river delta using NBRIP-agar and NBRIP-BPB broth containing tricalcium phosphate as the phosphate source. Based on phenotypic and molecular characterization, the strain was identified as sp. The maximum phosphate solubilizing activity of the strain was determined to be 44.84 μg/ml, accompanied by a decrease in pH of the growth medium from 7.0 to 3.15. During phosphate solubilization, various organic acids, such as malic acid (237 mg/l), lactic acid (599.5 mg/l) and acetic acid (5.0 mg/l) were also detected in the broth culture through HPLC analysis. Acid phosphatase activity was determined by performing p-nitrophenyl phosphate assay (pNPP) of the bacterial broth culture. Optimum acid phosphatase activity was observed at 48 h of incubation (76.808 U/ml), temperature of 45 °C (77.87 U/ml), an agitation rate of 100 rpm (80.40 U/ml), pH 5.0 (80.66 U/ml) and with glucose as a original carbon source (80.6 U/ml) and ammonium sulphate as a original nitrogen source (80.92 U/ml). Characterization of the partially purified acid phosphatase showed maximum activity at pH 5.0 (85.6 U/ml), temperature of 45 °C (97.87 U/ml) and substrate concentration of 2.5 mg/ml (92.7 U/ml). Hence the present phosphate solubilizing and acid phosphatase production activity of the bacterium may have probable use for future industrial, agricultural and biotechnological application.
磷是所有生命形式所必需的元素。解磷细菌能够通过溶解和矿化过程将磷酸盐转化为生物可利用的形式。因此，在本研究中，使用含有磷酸三钙作为磷源的NBRIP - 琼脂和NBRIP - BPB肉汤，从马哈纳迪河三角洲的红树林土壤中分离出一株解磷细菌PSB - 37。基于表型和分子特征，该菌株被鉴定为 属。该菌株的最大解磷活性被测定为44.84μg/ml，同时生长培养基的pH值从7.0降至3.15。在磷酸盐溶解过程中，通过HPLC分析还在肉汤培养物中检测到了各种有机酸，如苹果酸（237mg/l）、乳酸（599.5mg/l）和乙酸（5.0mg/l）。通过对细菌肉汤培养物进行对硝基苯磷酸酯测定（pNPP）来确定酸性磷酸酶活性。在培养48小时（76.808U/ml）、温度为45°C（77.87U/ml）、搅拌速率为100rpm（80.40U/ml）、pH 5.0（80.66U/ml）以及以葡萄糖作为原始碳源（80.6U/ml）和硫酸铵作为原始氮源（80.92U/ml）时观察到最佳酸性磷酸酶活性。对部分纯化的酸性磷酸酶的表征显示，在pH 5.0（85.6U/ml）、温度为45°C（97.87U/ml）和底物浓度为2.5mg/ml（92.7U/ml）时具有最大活性。因此，该细菌目前的解磷和酸性磷酸酶生产活性可能在未来的工业、农业和生物技术应用中具有潜在用途。
