College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, Jiangsu, 210014, China.
Sci Rep. 2019 Oct 25;9(1):15291. doi: 10.1038/s41598-019-51804-7.
Organophosphorus compounds (OP) are stable P source in nature, and can increase eutrophication risk in waterbodies. Lecithin was the most difficult OP to be broken down. In this study, two typical phosphate-solubilizing microorganisms, Aspergillus niger and Acinetobacter sp., were applied to evaluate their ability to decompose both inorganic phosphates and lecithin. A. niger and Acinetobacter sp. could solubilize calcium phosphates by secreting various organic acids, e.g., oxalic and formic acids. The fungus, A. niger, shows significantly higher ability of solubilizing these inorganic phosphates than Acinetobacter sp., primarily due to its secretion of abundant oxalic acid. However, the bacterium, Acinetobacter sp., could secrete more acid phosphatase than A. niger for lecithin decomposition, i.e., 9300 vs. 8500 μmol L h. Moreover, after addition of CaCl, the released P from lecithin was transformed to stable chlorapatite in the medium. To the contrast, Ca cations inclined to form calcium oxalate (rather than stable phosphate mineral) after the incubation of A. niger, as it induced relatively acidic environment after breaking down lecithin. Therefore, this work sheds light on the bright future of applying bacteria and Ca cations in OP pollutant management.
有机磷化合物（OP）是自然界中稳定的磷源，会增加水体富营养化的风险。卵磷脂是最难分解的有机磷化合物。在本研究中，两种典型的解磷微生物，黑曲霉和不动杆菌，被应用于评估它们分解无机磷酸盐和卵磷脂的能力。黑曲霉和不动杆菌通过分泌各种有机酸（如草酸和甲酸）来溶解磷酸钙。真菌黑曲霉对这些无机磷酸盐的溶解能力明显高于不动杆菌，主要是因为其分泌了丰富的草酸。然而，不动杆菌比黑曲霉分泌更多的酸性磷酸酶来分解卵磷脂，即 9300 比 8500 μmol L h。此外，在添加氯化钙后，从卵磷脂中释放的磷在培养基中转化为稳定的氯磷灰石。相比之下，在黑曲霉分解卵磷脂后，钙离子倾向于形成草酸钙（而不是稳定的磷酸盐矿物），因为它在分解卵磷脂后会诱导相对酸性的环境。因此，这项工作为应用细菌和钙离子来管理有机磷污染物提供了新的思路。
