Plymale Andrew E, Wells Jacqueline R, Pearce Carolyn I, Brislawn Colin J, Graham Emily B, Cheeke Tanya E, Allen Jessica L, Fansler Sarah J, Arey Bruce W, Bowden Mark E, Saunders Danielle L, Danna Vincent G, Tyrrell Kimberly J, Weaver Jamie L, Sjöblom Rolf, Vicenzi Edward P, McCloy John S, Hjärthner-Holdar Eva, Englund Mia, Ogenhall Erik, Peeler David K, Kruger Albert A
Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99352, USA.
School of Biological Sciences, Washington State University, Richland, WA, 99354, USA.
Int Biodeterior Biodegradation. 2020 Aug 31;38(1). doi: 10.1080/01490451.2020.1807658.
Because microbes cannot be eliminated from radioactive waste disposal facilities, the consequences of bio-colonization must be understood. At a pre-Viking era vitrified hillfort, Broborg, Sweden, anthropogenic glass has been subjected to bio-colonization for over 1,500 years. Broborg is used as a habitat analogue for disposed radioactive waste glass to inform how microbial processes might influence long-term glass durability. Electron microscopy and DNA sequencing of surficial material from the Broborg vitrified wall, adjacent soil, and general topsoil show that the ancient glass supports a niche microbial community of bacteria, fungi, and protists potentially involved in glass alteration. Communities associated with the vitrified wall are distinct and less diverse than soil communities. The vitrified niche of the wall and adjacent soil are dominated by lichens, lichen-associated microbes, and other epilithic, endolithic, and epigeic organisms. These organisms exhibit potential bio-corrosive properties, including silicate dissolution, extraction of essential elements, and secretion of geochemically reactive organic acids, that could be detrimental to glass durability. However, long-term biofilms can also possess a homeostatic function that could limit glass alteration. This study demonstrates potential impacts that microbial colonization and niche partitioning can have on glass alteration, and subsequent release of radionuclides from a disposal facility for vitrified radioactive waste.
由于微生物无法从放射性废物处置设施中消除，因此必须了解生物定殖的后果。在瑞典布罗堡一个维京时代之前的玻璃化山丘堡垒中，人为玻璃已经经历了1500多年的生物定殖。布罗堡被用作处置放射性废物玻璃的栖息地类似物，以了解微生物过程如何影响玻璃的长期耐久性。对布罗堡玻璃化墙壁、邻近土壤和表层土的表面物质进行电子显微镜和DNA测序表明，古老的玻璃支持着一个由细菌、真菌和原生生物组成的特殊微生物群落，这些微生物可能参与玻璃蚀变。与玻璃化墙壁相关的群落与土壤群落不同，且多样性较低。墙壁的玻璃化生态位和邻近土壤以地衣、与地衣相关的微生物以及其他石表、石内和地表生物为主。这些生物表现出潜在的生物腐蚀特性，包括硅酸盐溶解、必需元素的提取以及地球化学反应性有机酸的分泌，这些可能对玻璃耐久性有害。然而，长期生物膜也可能具有稳态功能，从而限制玻璃蚀变。本研究证明了微生物定殖和生态位划分对玻璃蚀变以及随后从玻璃化放射性废物处置设施中释放放射性核素可能产生的潜在影响。
