Department of Natural Resource Sciences, McGill University, Montreal, Canada.
Extremophiles. 2012 Mar;16(2):177-91. doi: 10.1007/s00792-011-0417-9. Epub 2012 Jan 14.
Lost Hammer (LH) spring is a unique hypersaline, subzero, perennial high Arctic spring arising through thick permafrost. In the present study, the microbial and geochemical characteristics of the LH outflow channels, which remain unfrozen at ≥-18°C and are more aerobic/less reducing than the spring source were examined and compared to the previously characterized spring source environment. LH channel sediments contained greater microbial biomass (~100-fold) and greater microbial diversity reflected by the 16S rRNA clone libraries. Phylotypes related to methanogenesis, methanotrophy, sulfur reduction and oxidation were detected in the bacterial clone libraries while the archaeal community was dominated by phylotypes most closely related to THE ammonia-oxidizing Thaumarchaeota. The cumulative percent recovery of (14)C-acetate mineralization in channel sediment microcosms exceeded ~30% and ~10% at 5 and -5°C, respectively, but sharply decreased at -10°C (≤1%). Most bacterial isolates (Marinobacter, Planococcus, and Nesterenkonia spp.) were psychrotrophic, halotolerant, and capable of growth at -5°C. Overall, the hypersaline, subzero LH spring channel has higher microbial diversity and activity than the source, and supports a variety of niches reflecting the more dynamic and heterogeneous channel environment.
失落之锤（LH）泉是一种独特的高盐、亚零摄氏度、常年存在于北极的泉水，源于厚厚的永冻层。在本研究中，我们对 LH 流出通道的微生物和地球化学特征进行了检查，并与之前描述的泉水源环境进行了比较。这些通道在≥-18°C 时保持不冻结，比泉水源更有氧/还原程度更低。LH 通道沉积物中含有更多的微生物生物量（100 倍）和更高的微生物多样性，这反映在 16S rRNA 克隆文库中。细菌克隆文库中检测到与甲烷生成、甲烷氧化、硫还原和氧化相关的型，而古菌群落主要由与氨氧化古菌（THE）最密切相关的型组成。通道沉积物微宇宙中（14）C-乙酸盐矿化的累积回收率分别在 5°C 和-5°C 时超过30%和~10%，但在-10°C 时急剧下降（≤1%）。大多数细菌分离株（Marinobacter、Planococcus 和 Nesterenkonia spp.）是嗜冷、耐盐的，能够在-5°C 下生长。总体而言，高盐、亚零摄氏度的 LH 泉通道比泉源具有更高的微生物多样性和活性，并支持各种反映更动态和异质化通道环境的生态位。
