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Alison E. Murray Fabien Kenig Christian H. Fritsen Christopher P. McKay Kaelin M. Cawley Ross Edwards Emanuele Kuhn Diane M. McKnight Nathaniel E. Ostrom Vivian Peng Adrian Ponce John C. Priscu Vladimir Samarkin Ashley T. Townsend Protima Wagh Seth A. Young Pung To Yung Peter T. Doran 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(50):20626-20631
The permanent ice cover of Lake Vida (Antarctica) encapsulates an extreme cryogenic brine ecosystem (−13 °C; salinity, 200). This aphotic ecosystem is anoxic and consists of a slightly acidic (pH 6.2) sodium chloride-dominated brine. Expeditions in 2005 and 2010 were conducted to investigate the biogeochemistry of Lake Vida’s brine system. A phylogenetically diverse and metabolically active Bacteria dominated microbial assemblage was observed in the brine. These bacteria live under very high levels of reduced metals, ammonia, molecular hydrogen (H2), and dissolved organic carbon, as well as high concentrations of oxidized species of nitrogen (i.e., supersaturated nitrous oxide and ∼1 mmol⋅L−1 nitrate) and sulfur (as sulfate). The existence of this system, with active biota, and a suite of reduced as well as oxidized compounds, is unusual given the millennial scale of its isolation from external sources of energy. The geochemistry of the brine suggests that abiotic brine-rock reactions may occur in this system and that the rich sources of dissolved electron acceptors prevent sulfate reduction and methanogenesis from being energetically favorable. The discovery of this ecosystem and the in situ biotic and abiotic processes occurring at low temperature provides a tractable system to study habitability of isolated terrestrial cryoenvironments (e.g., permafrost cryopegs and subglacial ecosystems), and is a potential analog for habitats on other icy worlds where water-rock reactions may cooccur with saline deposits and subsurface oceans. 相似文献
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Katarina Gojko Kanurić Spasenija Danilo Milanović Bojana Branko Ikonić Eva Stjepan Lončar Mirela Dragoljub Iličić Vladimir Radovan Vukić Dajana Vukota Vukić 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2018,26(4):1229-1234
The aim of this research was to investigate the effect of new, non-conventional starter culture on the kinetics of the lactose transformation during milk fermentation by kombucha, at pH 5.8; 5.4; 5.1; 4.8; and 4.6, at two different temperatures 37 °C and 42 °C. Milk fermentation at 42 °C lasted significantly shorter (about 5 h, 30 min) compared to the fermentation at 37 °C. Changes of lactose concentration at the both temperatures are consisting of two retaining stages and very steep decline in–between. The analysis of the rate curves showed that the reaction rate passes through the maximum after 9 h, 30 min at 37 °C and after 4 h at 42 °C. The sigmoidal saturation curve indicates a complex kinetics of lactose fermentation by kombucha starter. 相似文献
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Vladimir Carli Peter Parzer Camilla Wasserman Birgitta Floderus Alan Apter Judit Balazs Shira Barzilay Julio Bobes Romuald Brunner Paul Corcoran Doina Cosman Padraig Cotter Romain Despalins Nadja Graber Francis Guillemin Christian Haring Jean‐Pierre Kahn Laura Mandelli Dragan Marusic Gergely Mészáros George J. Musa Vita Postuvan Franz Resch Pilar A. Saiz Merike Sisask Airi Varnik Marco Sarchiapone Christina W. Hoven Danuta Wasserman 《Addiction (Abingdon, England)》2012,107(12):2210-2222
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