Drewniak Łukasz, Skłodowska Aleksandra, Manecki Maciej, Bajda Tomasz
Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland.
Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland.
Chemosphere. 2017 Mar;171:302-307. doi: 10.1016/j.chemosphere.2016.12.056. Epub 2016 Dec 21.
The main purpose of this study was to test if microorganisms isolated from heavily polluted environments can enhance dissolution of Pb-apatite (pyromorphite) resulting in remobilization of lead. Three bacterial strains belonging to the genus Pseudomonas isolated from underground mines in SW Poland were used in batch experiments of pyromorphite solubilization carried out in phosphate reach and phosphate poor media. Bacteria growth and evolution of Pb and phosphate concentrations as well as pH were determined. Additionally the concentration of bacterial siderophores in leaching solution was assayed. All bacterial strains were able to grow in both media in the presence of pyromorphite. The number of bacterial cells was from one to two orders of magnitude higher in the phosphate rich media. In the phosphate poor media the only source of P was the dissolving lead apatite. Bacteria enhanced the solubility of pyromorphite resulting in elevated Pb concentrations, up to 853 μg L in phosphate-rich medium and 6112 μg L in phosphate-poor medium, compared to less than 100 μg L in an abiotic control sample. Production of siderophores was characteristic for each culture and was much lower (10-1000 fold) in the phosphate-poor medium. This study demonstrates for the first time that indigenous bacteria can directly and indirectly promote the mobilization of lead from pyromorphite. This phenomenon should be considered in long term risk assessment of Pb contaminated soils after reclamation processes because bacteria can play a significant role in the efficiency of clean-up efforts and overall geochemical cycling of Pb.
本研究的主要目的是测试从污染严重的环境中分离出的微生物是否能增强铅磷灰石（磷氯铅矿）的溶解，从而导致铅的重新活化。从波兰西南部的地下矿井中分离出的三株假单胞菌属细菌，用于在富含磷酸盐和贫磷酸盐培养基中进行的磷氯铅矿溶解的批量实验。测定了细菌生长情况以及铅、磷酸盐浓度和pH值的变化。此外，还测定了浸出液中细菌铁载体的浓度。所有细菌菌株在存在磷氯铅矿的情况下都能在两种培养基中生长。在富含磷酸盐的培养基中，细菌细胞数量高出一到两个数量级。在贫磷酸盐培养基中，磷的唯一来源是溶解的铅磷灰石。细菌增强了磷氯铅矿的溶解度，导致铅浓度升高，在富含磷酸盐的培养基中高达853μg/L，在贫磷酸盐培养基中高达6112μg/L，相比之下，非生物对照样品中的铅浓度低于100μg/L。铁载体的产生因每种培养物而异，在贫磷酸盐培养基中要低得多（10 - 1000倍）。本研究首次证明本地细菌可以直接和间接地促进磷氯铅矿中铅的活化。在对开垦后受铅污染土壤的长期风险评估中应考虑这一现象，因为细菌在清理工作的效率和铅的整体地球化学循环中可能发挥重要作用。
