SGER: Novel Extremophiles from Highly Radioactive Waste Tanks

小行星9817825 放射性同位素的生产产生了大量的高放射性废物。 在能源部的萨凡纳河站点（SRS），大约7亿居里储存在75万至130万美制加仑的储罐中。 人们曾认为，这些碳钢单壳罐中的高辐射水平和高碱性pH值会阻止微生物生长。 最近在一些腐蚀、泄漏的储罐中发现了细菌;有可能一些腐蚀是由于生物过程造成的。 能够同时承受高放射性、高温和碱性pH值的生命形式在科学上是未知的。 在这项SGER研究中，Juergen Wiegels、Lawrence Shimkets和Carl Fliermans将从SRS高放废液罐中获得微生物培养物。 他们希望表明，液体样品可以无菌和安全地从这种罐中收集;细菌将在置于罐中的基质（试样）上定植，这些试样可以安全和有效地回收;回收的细菌可以培养，并将在高辐射环境中生长;培养物可以保存在放射性足够低的培养基中，以便进一步操作; 16 S rDNA序列可以从这些细菌中获得并用于表征它们的系统发育位置。 这些活动的成功将使看起来最独特的微生物组合之一，对遗传学，分子进化和生物退化研究具有重要意义，可用于进一步研究。

9817825 Wiegel The production of radioisotopes has resulted in large amounts of highly radioactive waste. At the Department of Energy's Savannah River Site (SRS), about 700 million curies are stored in tanks of 750,000 to 1,300,000 US gallons. It had been assumed that the high levels of radiation and the highly alkaline pH in these carbon-steel, single-shell tanks would prevent microbial growth. Bacteria were recently discovered in some corroded, leaking tanks; it is possible that some of the corrosion is due to biological processes. Life forms that can simultaneously withstand the high radioactivity, elevated temperatures, and alkaline pH in these tanks are unknown to science. In this SGER research, Juergen Wiegels, Lawrence Shimkets, and Carl Fliermans are to obtain microbial cultures from an SRS high level waste tank. They wish to show that liquid samples can be aseptically and safely collected from such tanks; that bacteria will colonize substrates (coupons) placed in the tank, and that these coupons can be safely and efficiently retrieved; that the retrieved bacteria can be cultivated, and will grow in high-radiation environments; that the cultures can be maintained in media sufficiently low in radioactivity to permit further manipulation; that 16S rDNA sequences can be obtained from these bacteria and used to characterize their phylogenetic position. Success in these activities would make what looks like one of the most unique assemblages of microbes, and one that would have significance for genetics, molecular evolution, and biodeterioration studies, available for further investigation.