Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413 Illkirch, Strasbourg, France; Agence de l'Environnement et de la Maîtrise de l'Energie, 20 Avenue du Grésillé, BP 90406, 49004 Angers Cedex 01, France.
Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413 Illkirch, Strasbourg, France.
J Hazard Mater. 2021 Feb 5;403:123699. doi: 10.1016/j.jhazmat.2020.123699. Epub 2020 Aug 13.
Since the ban on the use of asbestos due to its carcinogenic properties, the removal of asbestos cement, representing the major asbestos-containing waste, has proven to be a challenge in most industrial countries. Asbestos-containing products are mainly disposed of in landfills and have remained untreated. Bioremediation involving bacteria previously reported the ability of Pseudomonas aeruginosa to release iron from flocking asbestos waste through a siderophore-driven mechanism. We examined the involvement of siderophore-producing Pseudomonas in the biodeterioration of asbestos cement. Iron and magnesium solubilization were evaluated by specific siderophore-producing mutants. The absence of one of the two siderophores affected iron extraction, whereas equivalent dissolution as that of the control was observed in the absence of siderophore. Both pyoverdine and pyochelin biosynthesis was repressed in the presence of asbestos cement, suggesting iron bioavailability from the waste. We compared the efficiency of various pyoverdines to scavenge iron from asbestos cement waste that revealed the efficiency of all pyoverdines. Pyoverdines were efficient in iron removal extracted continuously, with no evident extraction limit, in long-term weathering experiments with these pyoverdines. The optimization of pyoverdine-asbestos weathering may allow the development of a bioremediation process to avoid the disposal of such waste in landfills.
由于石棉具有致癌特性，自其被禁用以来，将石棉水泥（主要的石棉废物）清除已成为大多数工业国家面临的一项挑战。含有石棉的产品主要被丢弃在垃圾填埋场，并未经过处理。先前有研究报告称，铜绿假单胞菌能够通过铁载体驱动机制从 flock 石棉废物中释放铁，从而实现生物修复。我们研究了产铁载体的假单胞菌在石棉水泥生物降解中的作用。通过特异性产铁载体突变体评估了铁和镁的溶解情况。两种铁载体中的一种缺失会影响铁的提取，而在不存在铁载体的情况下，观察到与对照相同的溶解。在存在石棉水泥的情况下，均抑制了 pyoverdine 和 pyochelin 的生物合成，表明废铁的生物可利用性。我们比较了各种 pyoverdines 从石棉水泥废铁中去除铁的效率，结果表明所有 pyoverdines 的效率均较高。pyoverdines 在长期风化实验中能够有效地连续去除铁，且没有明显的提取极限。优化 pyoverdine-石棉风化可能有助于开发一种生物修复过程，以避免将此类废物丢弃在垃圾填埋场中。
