SGER: Novel Extremophiles from Highly Radioactive Waste Tanks

9817825维格尔放射性同位素的生产产生了大量高放射性废物。在能源部的萨凡纳河遗址(SRS)，大约7亿居里储存在75万至130万加仑的水箱中。人们一直认为，这些碳钢单壳储罐中高水平的辐射和高度碱性的pH值将阻止微生物生长。最近在一些腐蚀、泄漏的储罐中发现了细菌；一些腐蚀可能是由于生物过程造成的。能够同时经受住这些水箱中的高放射性、高温和碱性pH的生命形式是科学未知的。在这项SGER研究中，Juergen Wiegels、Lawrence Shimkets和Carl Flierman将从SRS高级废物箱中获得微生物培养物。他们希望表明，从这种储罐中可以无菌和安全地采集液体样本；细菌将定植在放置在储罐中的底物(优惠券)上，这些优惠券可以安全有效地回收；回收的细菌可以培养，并将在高辐射环境中生长；培养物可以在放射性足够低的培养基中保持，以便进一步操作；可以从这些细菌中获得16S rDNA序列，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，以及对遗传学、分子进化和生物退化研究具有重要意义的微生物组合，可以进行进一步的研究。

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.