Bacterial dissolution of fluorapatite as a possible source of elevated dissolved phosphate in the environment
Bacterial dissolution of fluorapatite as a possible source of elevated dissolved phosphate in the environment
复制标题
氟磷灰石的细菌溶解是环境中溶解磷酸盐升高的可能来源
DOI：
10.1016/j.gca.2011.07.019
复制
发表时间：
2011-10-01
影响因子：
5
通讯作者：
Ellam, Robert M.
中科院分区：
文献类型：
--
作者：
Feng, Mu-hua;Ngwenya, Bryne T.;Ellam, Robert M.
为了了解地质磷对湖泊富营养化的贡献，我们研究了氟磷灰石溶解的速率和程度，在两种常见的土壤细菌（成团泛菌和巨大芽孢杆菌）的存在下，在T = 25摄氏度，26天。比较了生物和非生物条件下磷灰石中钙、磷和稀土元素的释放情况，探讨了微生物对磷灰石溶解的影响。在细菌的影响下，钙和磷的释放增加。磷灰石的溶解速率从溶液中的钙浓度在生物反应器中增加以上的错误相比，非生物控制。生物量的化学分析表明，细菌清除钙，磷，稀土元素在其生长过程中，降低其流体浓度，导致明显较低的释放速率。反应器中pH值的时间演变反映了磷灰石风化、溶液反应、细菌代谢和潜在的二次沉淀的平衡，这暗示了生物和非生物反应器中稀土元素模式的多样性。轻稀土元素（LREE）优先吸附到细胞表面，而重稀土元素（HREE）保留在流体相中。LREE和HREE的解耦可能是由于磷灰石中HREE的优先释放或LREE富集磷酸盐的选择性二次沉淀，特别是在细菌存在下。当细胞内浓度校正，两个生物反应器表现出高的P和REE释放与非生物控制相比。我们推测，缺乏这种校正解释了有关细菌在矿物风化率中的作用的相互矛盾的发现。细菌促进磷灰石中磷和稀土元素释放的现象可以解释水环境中磷负荷和金属污染的部分原因。(C)2011爱思唯尔有限公司保留所有权利。
In order to understand the contribution of geogenic phosphorus to lake eutrophication, we have investigated the rate and extent of fluorapatite dissolution in the presence of two common soil bacteria (Pantoea agglomerans and Bacillus megaterium) at T = 25 degrees C for 26 days. The release of calcium (Ca), phosphorus (P), and rare earth elements (REE) under biotic and abiotic conditions was compared to investigate the effect of microorganism on apatite dissolution. The release of Ca and P was enhanced under the influence of bacteria. Apatite dissolution rates obtained from solution Ca concentration in the biotic reactors increased above error compared with abiotic controls. Chemical analysis of biomass showed that bacteria scavenged Ca, P, and REE during their growth, which lowered their fluid concentrations, leading to apparent lower release rates. The temporal evolution of pH in the reactors reflected the balance of apatite weathering, solution reactions, bacterial metabolism, and potentially secondary precipitation, which was implied in the variety of REE patterns in the biotic and abiotic reactors. Light rare earth elements (LREE) were preferentially adsorbed to cell surfaces, whereas heavy rare earth elements (HREE) were retained in the fluid phase. Decoupling of LREE and HREE could possibly be due to preferential release of HREE from apatite or selective secondary precipitation of LREE enriched phosphates, especially in the presence of bacteria. When corrected for intracellular concentrations, both biotic reactors showed high P and REE release compared with the abiotic control. We speculate that lack of this correction explains the conflicting findings about the role of bacteria in mineral weathering rates. The observation that bacteria enhance the release rates of P and REE from apatite could account for some of the phosphorus burden and metal pollution in aquatic environments. (C) 2011 Elsevier Ltd. All rights reserved.