Gilichinsky D, Rivkina E, Shcherbakova V, Laurinavichuis K, Tiedje J
Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
Astrobiology. 2003 Summer;3(2):331-41. doi: 10.1089/153110703769016424.
This study describes brine lenses (cryopegs) found in Siberian permafrost derived from ancient marine sediment layers of the Arctic Ocean. The cryopegs were formed and isolated from sediment ~100,000-120,000 years ago. They remain liquid at the in situ temperature of -10 degrees C as a result of their high salt content (170-300 g/L). [(14)C] Glucose is taken up by the cryopeg biomass at -15 degrees C, indicating microbial metabolism at low temperatures in this habitat. Furthermore, aerobic, anaerobic heterotrophs, sulfate reducers, acetogens, and methanogens were detected by most probable number analysis. Two psychrophilic microbes were isolated from the cryopegs, a Clostridium and a Psychrobacter. The closest relatives of each were previously isolated from Antarctica. The cryopeg econiche might serve as a model for extraterrestrial life, and hence is of particular interest to astrobiology.
本研究描述了在源自北冰洋古代海洋沉积层的西伯利亚永久冻土中发现的卤水透镜体（低温盐水层）。这些低温盐水层在约10万至12万年前形成并与沉积物隔离。由于其高盐含量（170 - 300克/升），它们在原地温度为 -10摄氏度时仍保持液态。在 -15摄氏度时，[¹⁴C]葡萄糖被低温盐水层生物量摄取，这表明该栖息地在低温下存在微生物代谢。此外，通过最大可能数分析检测到了好氧、厌氧异养菌、硫酸盐还原菌、产乙酸菌和产甲烷菌。从低温盐水层中分离出两种嗜冷微生物，一种梭菌属细菌和一种嗜冷杆菌属细菌。它们各自最亲近的亲属先前是从南极洲分离出来的。低温盐水层生态龛可能是外星生命的一个模型，因此对天体生物学具有特别的意义。
