10,785 results match your criteria Antarctic Science[Journal]


Landfast ice: a major driver of reproductive success in a polar seabird.

Biol Lett 2021 Jun 16;17(6):20210097. Epub 2021 Jun 16.

Centre d'Études Biologiques de Chizé (CEBC), CNRS UMR 7372, 79360 Villiers en Bois, France.

In a fast-changing world, polar ecosystems are threatened by climate variability. Understanding the roles of fine-scale processes, and linear and nonlinear effects of climate factors on the demography of polar species is crucial for anticipating the future state of these fragile ecosystems. While the effects of sea ice on polar marine top predators are increasingly being studied, little is known about the impacts of landfast ice (LFI) on this species community. Read More

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The ocular pyogranulomatous lesion in a Gentoo penguin (Pygoscelis papua) from the Antarctic Peninsula: evaluation of microbiological and histopathological analysis outcomes.

Vet Res Commun 2021 Jun 15. Epub 2021 Jun 15.

Department of Microbiology, Faculty of Veterinary Medicine, Erciyes University, Kayseri, Turkey.

In this study, it was aimed to present the results of microbiological, cytological, histopathological, and immunohistochemical analyses of ocular samples from an Antarctic (Ardley Island, King George Island) Gentoo penguin chick (Pygoscelis papua) with a pyogranulomatous lesion in the right eye. Samples were taken from both the healthy left eye and the lesion in the right eye. Conventional culture methods and phenotypic and molecular tests were used for bacterial isolation and identification, respectively. Read More

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F-type lectin from serum of the Antarctic teleost fish Trematomus bernacchii (Boulenger, 1902): Purification, structural characterization, and bacterial agglutinating activity.

Comp Biochem Physiol B Biochem Mol Biol 2021 Jun 11:110633. Epub 2021 Jun 11.

Marine Immunobiology Laboratory, Department of Earth and Marine Sciences, University of Palermo, Palermo, Italy. Electronic address:

The increasing availability of sequenced genomes has enabled a deeper understanding of the complexity of fish lectin repertoires involved in early development and immune recognition. The teleost fucose-type lectin (FTL) family includes proteins that preferentially bind fucose and display tandemly arrayed carbohydrate-recognition domains (CRDs) or are found in mosaic combinations with other domains. They function as opsonins, promoting phagocytosis and the clearance of microbial pathogens. Read More

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Fur seals do, but sea lions don't - cross taxa insights into exhalation during ascent from dives.

Philos Trans R Soc Lond B Biol Sci 2021 Aug 14;376(1830):20200219. Epub 2021 Jun 14.

Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, UK.

Management of gases during diving is not well understood across marine mammal species. Prior to diving, phocid (true) seals generally exhale, a behaviour thought to assist with the prevention of decompression sickness. Otariid seals (fur seals and sea lions) have a greater reliance on their lung oxygen stores, and inhale prior to diving. Read More

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The largest moss carpet transplant in Antarctica and its bryosphere cryptic biodiversity.

Extremophiles 2021 Jun 11. Epub 2021 Jun 11.

Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

As part of the reconstruction of the Brazilian Antarctic Station on King George Island, three areas of moss carpet were transplanted to minimize the impact of the new facilities on the local biodiversity. A total of 650 m of moss carpet was transplanted to neighboring but previously uncolonized locations and has subsequently survived for the last 3 years. Antarctic moss carpets typically comprise low moss species diversity and are often monospecific. Read More

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Ice-shelf retreat drives recent Pine Island Glacier speedup.

Sci Adv 2021 Jun 11;7(24). Epub 2021 Jun 11.

British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK.

Speedup of Pine Island Glacier over the past several decades has made it Antarctica's largest contributor to sea-level rise. The past speedup is largely due to grounding-line retreat in response to ocean-induced thinning that reduced ice-shelf buttressing. While speeds remained fairly steady from 2009 to late 2017, our Copernicus Sentinel 1A/B-derived velocity data show a >12% speedup over the past 3 years, coincident with a 19-km retreat of the ice shelf. Read More

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Multidecadal poleward shift of the southern boundary of the Antarctic Circumpolar Current off East Antarctica.

Sci Adv 2021 Jun 11;7(24). Epub 2021 Jun 11.

Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.

The southern boundary (SB) of the Antarctic Circumpolar Current, the southernmost extent of the upper overturning circulation, regulates the Antarctic thermal conditions. The SB's behavior remains unconstrained because it does not have a clear surface signature. Revisited hydrographic data from off East Antarctica indicate full-depth warming from 1996 to 2019, concurrent with an extensive poleward shift of the SB subsurface isotherms (>50 km), which is most prominent at 120°E off the Sabrina Coast. Read More

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Urine metabolite profiling of Indian Antarctic Expedition members: NMR spectroscopy-based metabolomic investigation.

Heliyon 2021 May 25;7(5):e07114. Epub 2021 May 25.

Defence Institute of Physiology and Allied Sciences (DIPAS), DRDO, Lucknow Road, Timarpur, New Delhi 110054, India.

The southernmost region of earth, Antarctica, has world's most challenging environments. Those who live for long time and work in Antarctic stations are subjected to environmental stresses such as cold weather, photoperiod variations leading to disrupted sleep cycles, constrained living spaces, dry air, non-availability of fresh food items, and high electromagnetic radiations, psychological factors, such as geographical and social isolation, etc. All these factors have a significant impact on the human body. Read More

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Transcriptomic analysis of shell repair and biomineralization in the blue mussel, Mytilus edulis.

BMC Genomics 2021 Jun 10;22(1):437. Epub 2021 Jun 10.

British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, CB3 0ET, Cambridge, UK.

Background: Biomineralization by molluscs involves regulated deposition of calcium carbonate crystals within a protein framework to produce complex biocomposite structures. Effective biomineralization is a key trait for aquaculture, and animal resilience under future climate change. While many enzymes and structural proteins have been identified from the shell and in mantle tissue, understanding biomieralization is impeded by a lack of fundamental knowledge of the genes and pathways involved. Read More

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Emerging evidence of resource limitation in an Antarctic seabird metapopulation after 6 decades of sustained population growth.

Oecologia 2021 Jun 9. Epub 2021 Jun 9.

Department of Agriculture, Water and the Environment, Australian Antarctic Division, Channel Highway, Kingston, TAS, 7050, Australia.

The influence of resource limitation on spatio-temporal population dynamics is a fundamental theme in ecology and the concepts of carrying capacity, density dependence and population synchrony are central to this theme. The life history characteristics of seabirds, which include use of disjunct patches of breeding habitat, high coloniality during breeding, strong philopatry, and central-place foraging, make this group well suited to studying this paradigm. Here, we investigate whether density-dependent processes are starting to limit population growth in the Adélie penguin metapopulation breeding in the Windmill Islands, East Antarctica, after 6 decades of growth. Read More

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Scaling of oscillatory kinematics and Froude efficiency in baleen whales.

J Exp Biol 2021 Jun 10. Epub 2021 Jun 10.

Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.

High efficiency lunate-tail swimming with high-aspect-ratio lifting surfaces has evolved in many vertebrate lineages, from fish to cetaceans. Baleen whales (Mysticeti) are the largest swimming animals that exhibit this locomotor strategy and present an ideal study system to examine how morphology and the kinematics of swimming scale to the largest body sizes. We used data from whale-borne inertial sensors coupled with morphometric measurements from aerial drones to calculate the hydrodynamic performance of oscillatory swimming in six baleen whale species ranging in body length from 5-25m (fin whale, Balaenoptera physalus; Bryde's whale, Balaenoptera edeni; sei whale, Balaenoptera borealis; Antarctic minke whales, Balaenoptera bonaerensis; humpback whales, Megaptera novaeangliae; and blue whales, Balaenoptera musculus). Read More

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Summertime sea-ice prediction in the Weddell Sea improved by sea-ice thickness initialization.

Sci Rep 2021 Jun 9;11(1):11475. Epub 2021 Jun 9.

Application Laboratory, VAiG, JAMSTEC, 3173-25, Showamachi, Kanazawa-ku, Yokohama City, Kanagawa, 236-0001, Japan.

Skillful sea-ice prediction in the Antarctic Ocean remains a big challenge due to paucity of sea-ice observations and insufficient representation of sea-ice processes in climate models. Using a coupled general circulation model, this study demonstrates skillful prediction of the summertime sea-ice concentration (SIC) in the Weddell Sea with wintertime SIC and sea-ice thickness (SIT) initializations. During low sea-ice years of the Weddell Sea, negative SIT anomalies initialized in June retain the memory throughout austral winter owing to horizontal advection of the SIT anomalies. Read More

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Fifty million years of beetle evolution along the Antarctic Polar Front.

Proc Natl Acad Sci U S A 2021 Jun;118(24)

Securing Antarctica's Environmental Future, School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia.

Global cooling and glacial-interglacial cycles since Antarctica's isolation have been responsible for the diversification of the region's marine fauna. By contrast, these same Earth system processes are thought to have played little role terrestrially, other than driving widespread extinctions. Here, we show that on islands along the Antarctic Polar Front, paleoclimatic processes have been key to diversification of one of the world's most geographically isolated and unique groups of herbivorous beetles-Ectemnorhinini weevils. Read More

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Use of melatonin as an inhibitor of apoptotic process for cryopreservation of zebrafish (Danio rerio) embryos.

Braz J Biol 2021 2;82:e241081. Epub 2021 Jun 2.

Universidade Estadual de Maringá - UEM, Departamento de Zootecnia, Maringá, PR, Brasil.

This study investigated the use of melatonin to arrest the effects of apoptosis in vitrified zebrafish (D. rerio) embryos. Dechorionated embryos at 22-24 somite-stage were divided (n = 60/treatment) into a non-vitrified (Control Group, 0 M melatonin) and vitrified treatments with 0 M (T1), 1 µM (T2) and 1 mM of melatonin (T3). Read More

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Nanomolar phosphate supply and its recycling drive net community production in the subtropical North Pacific.

Nat Commun 2021 06 8;12(1):3462. Epub 2021 Jun 8.

Meteorological Research Institute, Japan Meteorological Agency, Ibaraki, Japan.

Seasonal drawdown of dissolved inorganic carbon (DIC) in the subtropical upper ocean makes a significant contribution to net community production (NCP) globally. Although NCP requires macronutrient supply, surface macronutrients are chronically depleted, and their supply has been unable to balance the NCP demand. Here, we report nanomolar increases in surface nitrate plus nitrite (N+N, ~20 nM) and phosphate (PO, ~15 nM) from summer to winter in the western subtropical North Pacific. Read More

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A living bdelloid rotifer from 24,000-year-old Arctic permafrost.

Curr Biol 2021 Jun;31(11):R712-R713

Soil Cryology Laboratory, Institute of Physicochemical and Biological Problems in Soil Science, Institutskaya 2, 142290, Pushchino, Russia.

In natural, permanently frozen habitats, some organisms may be preserved for hundreds to tens of thousands of years. For example, stems of Antarctic moss were successfully regrown from an over millennium-old sample covered by ice for about 400 years. Likewise, whole campion plants were regenerated from seed tissue preserved in relict 32,000-year-old permafrost, and nematodes were revived from the permafrost of two localities in northeastern Siberia, with source sediments dated over 30,000 years BP. Read More

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Marine habitat use and feeding ecology of introduced anadromous brown trout at the colonization front of the sub-Antarctic Kerguelen archipelago.

Sci Rep 2021 Jun 7;11(1):11917. Epub 2021 Jun 7.

Université de Pau et des Pays de l'Adour, e2s UPPA, INRAE, ECOBIOP, Aquapôle INRAE, Saint-Pée-sur-Nivelle, France.

In 1954, brown trout were introduced to the Kerguelen archipelago (49°S, 70°E), a pristine, sub-Antarctic environment previously devoid of native freshwater fishes. Trout began spreading rapidly via coastal waters to colonize adjacent watersheds, however, recent and unexpectedly the spread has slowed. To better understand the ecology of the brown trout here, and why their expansion has slowed, we documented the marine habitat use, foraging ecology, and environmental conditions experienced over one year by 50 acoustically tagged individuals at the colonization front. Read More

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Hi-C scaffolded short- and long-read genome assemblies of the California sea lion are broadly consistent for syntenic inference across 45 million years of evolution.

Mol Ecol Resour 2021 Jun 7. Epub 2021 Jun 7.

Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany.

With the advent of chromatin-interaction maps, chromosome-level genome assemblies have become a reality for a wide range of organisms. Scaffolding quality is, however, difficult to judge. To explore this gap, we generated multiple chromosome-scale genome assemblies of an emerging wild animal model for carcinogenesis, the California sea lion (Zalophus californianus). Read More

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Food for all: designing sustainable and secure future seafood systems.

Rev Fish Biol Fish 2021 May 29:1-21. Epub 2021 May 29.

Centre for Marine Socioecology, University of Tasmania, Hobart, TAS Australia.

Food from the sea can make a larger contribution to healthy and sustainable diets, and to addressing hunger and malnutrition, through improvements in production, distribution and equitable access to wild harvest and mariculture resources and products. The supply and consumption of seafood is influenced by a range of 'drivers' including ecosystem change and ocean regulation, the influence of corporations and evolving consumer demand, as well as the growing focus on the importance of seafood for meeting nutritional needs. These drivers need to be examined in a holistic way to develop an informed understanding of the needs, potential impacts and solutions that align seafood production and consumption with relevant 2030 Sustainable Development Goals (SDGs). Read More

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Divergence time and species delimitation of microbivalves in the Southern Ocean: the case of species.

Polar Biol 2021 Jun 1:1-13. Epub 2021 Jun 1.

Centro FONDAP- IDEAL, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.

The systematics of Subantarctic and Antarctic near-shore marine benthic invertebrates requires major revision and highlights the necessity to incorporate additional sources of information in the specimen identification chart in the Southern Ocean (SO). In this study, we aim to improve our understanding of the biodiversity of (Dall 1876) through molecular and morphological comparisons of Antarctic and Subantarctic taxa. The microbivalves of the genus are small brooding organisms that inhabit intertidal and shallow subtidal rocky ecosystems. Read More

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Making marinas bivalve friendly for enhanced biodiversity outcomes.

Mar Pollut Bull 2021 Jun 1;169:112464. Epub 2021 Jun 1.

National Centre for Coasts and Climate, School of BioSciences, The University of Melbourne, Victoria, Australia; Institute for Marine and Antarctic Science, University Tasmania, Hobart, Tasmania, Australia. Electronic address:

Natural coastlines are being replaced by artificial structures (pilings, pontoons, breakwaters), with negative environmental impacts, particularly in marinas. Ropes seeded with mussels (Mytilus galloprovincialis) were added to artificial structures in a marina, using aquaculture techniques, to reduce the colonisation of invasive taxa. After 6-months, droplines beneath pontoons had the highest seeded mussel survival and growth, richness of native and invasive taxa, and proportion of invasive to native taxa, compared with the other interventions. Read More

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Characteristics of a Cold-Adapted L-glutaminase with Potential Applications in the Food Industry.

Appl Biochem Biotechnol 2021 Jun 3. Epub 2021 Jun 3.

Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Centro de Investigaciones y Transferencia de Entre Ríos (CITER), Monseñor Tavella 1450 (E3202 BCJ), Concordia, Entre Ríos, Argentina.

L-glutaminases are enzymes that catalyze the hydrolysis of L-glutamine, producing L-glutamate and ammonium, and they have promising applications in pharmaceutical and food industries. Several investigations have focused on thermo-tolerant L-glutaminases; however, studies on cold-adapted L-glutaminases have not been reported. These enzymes could be useful in the food industry because they display high catalytic activity at low and room temperatures, a valuable feature in processes aimed to save energy. Read More

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Effect of dietary protein on energy metabolism including protein synthesis in the spiny lobster Sagmariasus verreauxi.

Sci Rep 2021 Jun 3;11(1):11814. Epub 2021 Jun 3.

Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 49, Hobart, TAS, 7001, Australia.

This is the first study in an aquatic ectotherm to combine a stoichiometric bioenergetic approach with an endpoint stochastic model to explore dietary macronutrient content. The combination of measuring respiratory gas (O and CO) exchange, nitrogenous (ammonia and urea) excretion, specific dynamic action (SDA), metabolic energy substrate use, and whole-body protein synthesis in spiny lobster, Sagmariasus verreauxi, was examined in relation to dietary protein. Three isoenergetic feeds were formulated with varying crude protein: 40%, 50% and 60%, corresponding to CP, CP and CP treatments, respectively. Read More

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Antarctic surface temperature and elevation during the Last Glacial Maximum.

Science 2021 06;372(6546):1097-1101

Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy.

Water-stable isotopes in polar ice cores are a widely used temperature proxy in paleoclimate reconstruction, yet calibration remains challenging in East Antarctica. Here, we reconstruct the magnitude and spatial pattern of Last Glacial Maximum surface cooling in Antarctica using borehole thermometry and firn properties in seven ice cores. West Antarctic sites cooled ~10°C relative to the preindustrial period. Read More

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Salp fecal pellets release more bioavailable iron to Southern Ocean phytoplankton than krill fecal pellets.

Curr Biol 2021 May 25. Epub 2021 May 25.

Marine Botany, University of Bremen, Bibliothekstraße 1, 28359 Bremen, Germany; Ecological Chemistry, Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.

Over the last decades, it has been reported that the habitat of the Southern Ocean (SO) key species Antarctic krill (Euphausia superba) has contracted to high latitudes, putatively due to reduced winter sea ice coverage, while salps as Salpa thompsoni have extended their dispersal to the former krill habitats. To date, the potential implications of this population shift on the biogeochemical cycling of the limiting micronutrient iron (Fe) and its bioavailability to SO phytoplankton has never been tested. Based on uptake of fecal pellet (FP)-released Fe by SO phytoplankton, this study highlights how efficiently krill and salps recycle Fe. Read More

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Endolithic Bacterial Diversity in Lichen-Dominated Communities Is Shaped by Sun Exposure in McMurdo Dry Valleys, Antarctica.

Microb Ecol 2021 Jun 3. Epub 2021 Jun 3.

Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy.

The diversity and composition of endolithic bacterial diversity of several locations in McMurdo Dry Valleys (Continental Antarctica) were explored using amplicon sequencing, targeting the V3 and V4 of the 16S region. Despite the increasing interest in edaphic factors that drive bacterial community composition in Antarctic rocky communities, few researchers focused attention on the direct effects of sun exposure on bacterial diversity; we herein reported significant differences in the northern and southern communities. The analysis of β-diversity showed significant differences among sampled localities. Read More

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Geographic Distance and Habitat Type Influence Fungal Communities in the Arctic and Antarctic Sites.

Microb Ecol 2021 Jun 3. Epub 2021 Jun 3.

China Pharmaceutical Culture Collection, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China.

The Antarctic and Arctic regions are collectively referred to as the "Two Poles" of the earth and have extremely harsh climate conditions and fragile ecosystems. Until now, the biogeography of the fungal communities in the bipolar regions is not well known. In this study, we focused on the fungal communities in 110 samples collected from four habitat types (i. Read More

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Investigating the Uptake and Fate of Poly- and Perfluoroalkylated Substances (PFAS) in Sea Ice Using an Experimental Sea Ice Chamber.

Environ Sci Technol 2021 Jun 3. Epub 2021 Jun 3.

Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom.

Poly- and perfluoroalkyl substances (PFAS) are contaminants of emerging Arctic concern and are present in the marine environments of the polar regions. Their input to and fate within the marine cryosphere are poorly understood. We conducted a series of laboratory experiments to investigate the uptake, distribution, and release of 10 PFAS of varying carbon chain length (C-C) in young sea ice grown from artificial seawater (NaClsolution). Read More

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Fine hyphal coils in the liverwort Cephaloziella varians increase in frequency in response to experimental warming in maritime Antarctica.

Authors:
Kevin K Newsham

Mycorrhiza 2021 Jun 2. Epub 2021 Jun 2.

British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.

Previous studies have shown changes to the frequencies of hyphal coils and other fungal structures in leafy liverwort tissues across latitudinal transects through Antarctica. Although suggestive of a role of temperature in determining the frequencies of fungal structures, these studies could not exclude the possibility that other factors which alter at lower latitudes-notably liquid water availability-were responsible for the observed patterns of fungal colonisation. Here, in a field experiment in maritime Antarctica, the effects of warming with open top chambers (OTCs) on the frequencies of fungal structures in the leafy liverwort Cephaloziella varians were determined. Read More

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Complete genome sequence of Arthrobacter sp. PAMC25564 and its comparative genome analysis for elucidating the role of CAZymes in cold adaptation.

BMC Genomics 2021 Jun 2;22(1):403. Epub 2021 Jun 2.

Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, 70 Sunmoon-ro 221, Tangjeong-myeon, 31460, Asan-si, Chungnam, Republic of Korea.

Background: The Arthrobacter group is a known set of bacteria from cold regions, the species of which are highly likely to play diverse roles at low temperatures. However, their survival mechanisms in cold regions such as Antarctica are not yet fully understood. In this study, we compared the genomes of 16 strains within the Arthrobacter group, including strain PAMC25564, to identify genomic features that help it to survive in the cold environment. Read More

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