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https://www.readbyqxmd.com/read/28314921/comparative-genomics-analysis-of-five-psychrobacter-strains-isolated-from-world-wide-habitats-reveal-high-intra-genus-variations
#1
Shan Zhang, Weizhi Song, Min Yu, Xuezheng Lin
Psychrobacter has been regarded as an important genus for bacterial cold adaptation studies. However, members of this genus are highly varied in terms of both cold adaptability and genome content. To get an understanding of the diversity of members of this genus, five Psychrobacter strains (G, K5, 273-4, PAMC21119 and PRwf-1), with publicly available complete/draft genome, were selected and comprehensive comparative genomics analyses were performed among them. The closest phylogenetic relationship, highest average nucleotide identity (96...
March 17, 2017: Extremophiles: Life Under Extreme Conditions
https://www.readbyqxmd.com/read/28289836/prokaryotic-abundance-and-activity-in-permafrost-of-the-northern-victoria-land-and-upper-victoria-valley-antarctica
#2
Rosabruna La Ferla, Maurizio Azzaro, Luigi Michaud, Gabriella Caruso, Angelina Lo Giudice, Rodolfo Paranhos, Anderson S Cabral, Antonella Conte, Alessandro Cosenza, Giovanna Maimone, Maria Papale, Alessandro Ciro Rappazzo, Mauro Guglielmin
Victoria Land permafrost harbours a potentially large pool of cold-affected microorganisms whose metabolic potential still remains underestimated. Three cores (BC-1, BC-2 and BC-3) drilled at different depths in Boulder Clay (Northern Victoria Land) and one sample (DY) collected from a core in the Dry Valleys (Upper Victoria Valley) were analysed to assess the prokaryotic abundance, viability, physiological profiles and potential metabolic rates. The cores drilled at Boulder Clay were a template of different ecological conditions (different temperature regime, ice content, exchanges with atmosphere and with liquid water) in the same small basin while the Dry Valleys site was very similar to BC-2 conditions but with a complete different geological history and ground ice type...
March 13, 2017: Microbial Ecology
https://www.readbyqxmd.com/read/28284636/data-driven-mapping-of-the-potential-mountain-permafrost-distribution
#3
Nicola Deluigi, Christophe Lambiel, Mikhail Kanevski
Existing mountain permafrost distribution models generally offer a good overview of the potential extent of this phenomenon at a regional scale. They are however not always able to reproduce the high spatial discontinuity of permafrost at the micro-scale (scale of a specific landform; ten to several hundreds of meters). To overcome this lack, we tested an alternative modelling approach using three classification algorithms belonging to statistics and machine learning: Logistic regression, Support Vector Machines and Random forests...
March 8, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28284141/characterization-of-pb-2-biosorption-by-psychrotrophic-strain-pseudomonas-sp-i3-isolated-from-permafrost-soil-of-mohe-wetland-in-northeast-china
#4
Dandan Li, Xingjian Xu, Hongwen Yu, Xuerong Han
Due to the long and severe winter in Northeast China, wastewater containing lead (Pb) is treated inefficiently, resulting in irregular disposal. In order to solve this problem, a Pb-resistant psychrotrophic bacterium, Pseudomonas sp. I3, was isolated from permafrost soil of Mohe wetland and served as biosorbent for Pb(2+) removal under 15 °C. The minimum inhibitory concentration of strain I3 for Pb(2+) was 7.5 mM, which was higher than that of Escherichia coli DH5α (1.5 mM). However, acid digestion results showed that these two bacteria had a comparable biosorption capacity for Pb(2+), suggesting no direct relationship between biosorption ability of bacteria and their metal-resistance...
March 8, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28280011/draft-genome-sequence-of-agrococcusbaldri-strain-marseille-p2731
#5
Pamela Afouda, Gregory Dubourg, Noemie Labas, Didier Raoult, Pierre-Edouard Fournier
Agrococcus baldri strain Marseille-P2731 was isolated from a Siberian permafrost specimen dated around 10 million years. The 3,021,022-bp genome of strain Marseille-P2731, with a 71.82% G+C content, includes 2,844 protein-coding genes, 72 toxin/antitoxin modules, nine bacteriocin-encoding genes, and 1,266 genes associated with mobilome.
March 9, 2017: Genome Announcements
https://www.readbyqxmd.com/read/28262362/freezing-enhanced-reduction-of-chromate-by-nitrite
#6
Kitae Kim, Hyun Young Chung, Jinjung Ju, Jungwon Kim
The redox reactions between pollutants and chemicals (e.g., pollutant, oxygen, and water) critically affect the fate and potential risk of pollutants, and their rates significantly depend on the environmental media. Although the kinetics and mechanism of various redox reactions in water have been extensively investigated, those in ice have been hardly explored, despite the large areal extent of the cryosphere, which includes permafrost, polar regions, and mid-latitudes during the winter season on Earth. In this study, we investigated the reduction of chromate (Cr(VI)) by nitrite (NO2(-)) in ice (i...
March 2, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28230151/potential-microbial-contamination-during-sampling-of-permafrost-soil-assessed-by-tracers
#7
Toke Bang-Andreasen, Morten Schostag, Anders Priemé, Bo Elberling, Carsten S Jacobsen
Drilling and handling of permanently frozen soil cores without microbial contamination is of concern because contamination e.g. from the active layer above may lead to incorrect interpretation of results in experiments investigating potential and actual microbial activity in these low microbial biomass environments. Here, we present an example of how microbial contamination from active layer soil affected analysis of the potentially active microbial community in permafrost soil. We also present the development and use of two tracers: (1) fluorescent plastic microspheres and (2) Pseudomonas putida genetically tagged with Green Fluorescent Protein production to mimic potential microbial contamination of two permafrost cores...
February 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28215329/biotechnological-applications-of-marine-enzymes-from-algae-bacteria-fungi-and-sponges
#8
S Parte, V L Sirisha, J S D'Souza
Diversity is the hallmark of all life forms that inhabit the soil, air, water, and land. All these habitats pose their unique inherent challenges so as to breed the "fittest" creatures. Similarly, the biodiversity from the marine ecosystem has evolved unique properties due to challenging environment. These challenges include permafrost regions to hydrothermal vents, oceanic trenches to abyssal plains, fluctuating saline conditions, pH, temperature, light, atmospheric pressure, and the availability of nutrients...
2017: Advances in Food and Nutrition Research
https://www.readbyqxmd.com/read/28208232/non-linear-co2-flux-response-to-seven-years-of-experimentally-induced-permafrost-thaw
#9
Marguerite Mauritz, Rosvel Bracho, Gerardo Celis, Jack Hutchings, Susan M Natali, Elaine Pegoraro, Verity G Salmon, Christina Schädel, Elizabeth E Webb, Edward A G Schuur
Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from seven years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO2 flux than Air warming. Soil warming caused rapid permafrost thaw and increased ecosystem respiration (Reco), gross primary productivity (GPP), and net summer CO2 storage (NEE)...
February 16, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28205612/dna-analysis-of-a-30-000-year-old-urocitellus-glacialis-from-northeastern-siberia-reveals-phylogenetic-relationships-between-ancient-and-present-day-arctic-ground-squirrels
#10
Marina Faerman, Gila Kahila Bar-Gal, Elisabetta Boaretto, Gennady G Boeskorov, Nikolai E Dokuchaev, Oleg A Ermakov, Fedor N Golenishchev, Stanislav V Gubin, Eugenia Mintz, Evgeniy Simonov, Vadim L Surin, Sergei V Titov, Oksana G Zanina, Nikolai A Formozov
In contrast to the abundant fossil record of arctic ground squirrels, Urocitellus parryii, from eastern Beringia, only a limited number of fossils is known from its western part. In 1946, unnamed GULAG prisoners discovered a nest with three mummified carcasses of arctic ground squirrels in the permafrost sediments of the El'ga river, Yakutia, Russia, that were later attributed to a new species, Citellus (Urocitellus) glacialis Vinogr. To verify this assignment and to explore phylogenetic relationships between ancient and present-day arctic ground squirrels, we performed (14)C dating and ancient DNA analyses of one of the El'ga mummies and four contemporaneous fossils from Duvanny Yar, northeastern Yakutia...
February 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28132402/direct-and-indirect-climate-change-effects-on-carbon-dioxide-fluxes-in-a-thawing-boreal-forest-wetland-landscape
#11
Manuel Helbig, Laura E Chasmer, Ankur R Desai, Natascha Kljun, William L Quinton, Oliver Sonnentag
In the sporadic permafrost zone of northwestern Canada, boreal forest carbon dioxide (CO2 ) fluxes will be altered directly by climate change through changing meteorological forcing and indirectly through changes in landscape functioning associated with thaw-induced collapse-scar bog ("wetland") expansion. However, their combined effect on landscape-scale net ecosystem CO2 exchange (NEELAND ), resulting from changing gross primary productivity (GPP) and ecosystem respiration (ER), remains unknown. Here, we quantify indirect land cover change impacts on NEELAND and direct climate change impacts on modeled temperature- and light-limited NEELAND of a boreal forest-wetland landscape...
January 28, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28117155/active-layer-and-permafrost-thermal-regime-in-a-patterned-ground-soil-in-maritime-antarctica-and-relationship-with-climate-variability-models
#12
D A Chaves, G B Lyra, M R Francelino, Ldb Silva, A Thomazini, Cegr Schaefer
Permafrost and active layer studies are important to understand and predict regional climate changes. The objectives of this work were: i) to characterize the soil thermal regime (active layer thickness and permafrost formation) and its interannual variability and ii) to evaluate the influence of different climate variability modes to the observed soil thermal regime in a patterned ground soil in Maritime Antarctica. The study was carried out at Keller Peninsula, King George Island, Maritime Antarctica. Six soil temperatures probes were installed at different depths (10, 30 and 80cm) in the polygon center (Tc) and border (Tb) of a patterned ground soil...
April 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28116688/spatiotemporal-variability-in-surface-energy-balance-across-tundra-snow-and-ice-in-greenland
#13
Magnus Lund, Christian Stiegler, Jakob Abermann, Michele Citterio, Birger U Hansen, Dirk van As
The surface energy balance (SEB) is essential for understanding the coupled cryosphere-atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt. For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw...
February 2017: Ambio
https://www.readbyqxmd.com/read/28116685/ecosystem-responses-to-climate-change-at-a-low-arctic-and-a-high-arctic-long-term-research-site
#14
John E Hobbie, Gaius R Shaver, Edward B Rastetter, Jessica E Cherry, Scott J Goetz, Kevin C Guay, William A Gould, George W Kling
Long-term measurements of ecological effects of warming are often not statistically significant because of annual variability or signal noise. These are reduced in indicators that filter or reduce the noise around the signal and allow effects of climate warming to emerge. In this way, certain indicators act as medium pass filters integrating the signal over years-to-decades. In the Alaskan Arctic, the 25-year record of warming of air temperature revealed no significant trend, yet environmental and ecological changes prove that warming is affecting the ecosystem...
February 2017: Ambio
https://www.readbyqxmd.com/read/28116680/a-synthesis-of-the-arctic-terrestrial-and-marine-carbon-cycles-under-pressure-from-a-dwindling-cryosphere
#15
REVIEW
Frans-Jan W Parmentier, Torben R Christensen, Søren Rysgaard, Jørgen Bendtsen, Ronnie N Glud, Brent Else, Jacobus van Huissteden, Torsten Sachs, Jorien E Vonk, Mikael K Sejr
The current downturn of the arctic cryosphere, such as the strong loss of sea ice, melting of ice sheets and glaciers, and permafrost thaw, affects the marine and terrestrial carbon cycles in numerous interconnected ways. Nonetheless, processes in the ocean and on land have been too often considered in isolation while it has become increasingly clear that the two environments are strongly connected: Sea ice decline is one of the main causes of the rapid warming of the Arctic, and the flow of carbon from rivers into the Arctic Ocean affects marine processes and the air-sea exchange of CO2...
February 2017: Ambio
https://www.readbyqxmd.com/read/28088543/transformation-of-terrestrial-organic-matter-along-thermokarst-affected-permafrost-coasts-in-the-arctic
#16
George Tanski, Hugues Lantuit, Saskia Ruttor, Christian Knoblauch, Boris Radosavljevic, Jens Strauss, Juliane Wolter, Anna M Irrgang, Justine Ramage, Michael Fritz
The changing climate in the Arctic has a profound impact on permafrost coasts, which are subject to intensified thermokarst formation and erosion. Consequently, terrestrial organic matter (OM) is mobilized and transported into the nearshore zone. Yet, little is known about the fate of mobilized OM before and after entering the ocean. In this study we investigated a retrogressive thaw slump (RTS) on Qikiqtaruk - Herschel Island (Yukon coast, Canada). The RTS was classified into an undisturbed, a disturbed (thermokarst-affected) and a nearshore zone and sampled systematically along transects...
January 11, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28068392/vegetation-changes-in-the-permafrost-regions-of-the-qinghai-tibetan-plateau-from-1982-2012-different-responses-related-to-geographical-locations-and-vegetation-types-in-high-altitude-areas
#17
Zhiwei Wang, Qian Wang, Xiaodong Wu, Lin Zhao, Guangyang Yue, Zhuotong Nan, Puchang Wang, Shuhua Yi, Defu Zou, Yu Qin, Tonghua Wu, Jianzong Shi
The Qinghai-Tibetan Plateau (QTP) contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition...
2017: PloS One
https://www.readbyqxmd.com/read/28066129/a-multi-year-estimate-of-methane-fluxes-in-alaska-from-carve-atmospheric-observations
#18
Scot M Miller, Charles E Miller, Roisin Commane, Rachel Y-W Chang, Steven J Dinardo, John M Henderson, Anna Karion, Jakob Lindaas, Joe R Melton, John B Miller, Colm Sweeney, Steven C Wofsy, Anna M Michalak
Methane (CH4) fluxes from Alaska and other arctic regions may be sensitive to thawing permafrost and future climate change, but estimates of both current and future fluxes from the region are uncertain. This study estimates CH4 fluxes across Alaska for 2012-2014 using aircraft observations from the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) and a geostatistical inverse model (GIM). We find that a simple flux model based on a daily soil temperature map and a static map of wetland extent reproduces the atmospheric CH4 observations at the state-wide, multi-year scale more effectively than global-scale, state-of-the-art process-based models...
October 2016: Global Biogeochemical Cycles
https://www.readbyqxmd.com/read/28062107/diurnal-evolution-of-the-temperature-sensitivity-of-co2-efflux-in-permafrost-soils-under-control-and-warm-conditions
#19
Julien Fouché, Catherine Keller, Michel Allard, Jean Paul Ambrosi
Cryosols contain ~33% of the global soil organic carbon. Cryosol warming and permafrost degradation may enhance the CO2 release to the atmosphere through the microbial decomposition. Despite the large carbon pool, the permafrost carbon feedback on the climate remains uncertain. In this study, we aimed at better understanding the diurnal evolution of the temperature sensitivity of CO2 efflux in Cryosols. A Histic Cryosol and a Turbic Cryosol were instrumented in tussock tundra ecosystems near Salluit (Nunavik, Canada)...
January 3, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28057338/effects-of-local-factors-and-climate-on-permafrost-conditions-and-distribution-in-beiluhe-basin-qinghai-tibet-plateau-china
#20
Guoan Yin, Fujun Niu, Zhanju Lin, Jing Luo, Minghao Liu
Beiluhe basin is underlain by warm and ice-rich permafrost, and covered by vegetation and soils characteristic of the Qinghai-Tibet Plateau. A field monitoring network was established to investigate permafrost conditions and to assess potential impacts of local factors and climate change. This paper describes the spatial variations in permafrost conditions from instrumented boreholes, controlling environmental factors, and recent thermal evolution of permafrost in the basin. The study area was divided into 10 ecotypes using satellite imagery based classification...
January 2, 2017: Science of the Total Environment
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