scholarly journals Metagenomic Analysis of Stress Genes in Microbial Mat Communities from Antarctica and the High Arctic

2011 ◽  
Vol 78 (2) ◽  
pp. 549-559 ◽  
Author(s):  
Thibault Varin ◽  
Connie Lovejoy ◽  
Anne D. Jungblut ◽  
Warwick F. Vincent ◽  
Jacques Corbeil
Keyword(s):  
High Arctic ◽  
Environmental Stresses ◽  
The Arctic ◽  
Functional Responses ◽  
Protein Coding ◽  
Content Type ◽  
Stress Genes ◽  
Cyanobacterial Genes ◽  
Shock Proteins ◽  
The Antarctic

ABSTRACTPolar and alpine microbial communities experience a variety of environmental stresses, including perennial cold and freezing; however, knowledge of genomic responses to such conditions is still rudimentary. We analyzed the metagenomes of cyanobacterial mats from Arctic and Antarctic ice shelves, using high-throughput pyrosequencing to test the hypotheses that consortia from these extreme polar habitats were similar in terms of major phyla and subphyla and consequently in their potential responses to environmental stresses. Statistical comparisons of the protein-coding genes showed similarities between the mats from the two poles, with the majority of genes derived fromProteobacteriaandCyanobacteria; however, the relative proportions differed, with cyanobacterial genes more prevalent in the Antarctic mat metagenome. Other differences included a higher representation ofActinobacteriaandAlphaproteobacteriain the Arctic metagenomes, which may reflect the greater access to diasporas from both adjacent ice-free lands and the open ocean. Genes coding for functional responses to environmental stress (exopolysaccharides, cold shock proteins, and membrane modifications) were found in all of the metagenomes. However, in keeping with the greater exposure of the Arctic to long-range pollutants, sequences assigned to copper homeostasis genes were statistically (30%) more abundant in the Arctic samples. In contrast, more reads matching the sigma B genes were identified in the Antarctic mat, likely reflecting the more severe osmotic stress during freeze-up of the Antarctic ponds. This study underscores the presence of diverse mechanisms of adaptation to cold and other stresses in polar mats, consistent with the proportional representation of major bacterial groups.

scholarly journals Polar endoliths – an anti-correlation of climatic extremes and microbial biodiversity

2002 ◽  
Vol 1 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Charles S. Cockell ◽  
Christopher P. McKay ◽  
Christopher Omelon
Keyword(s):  
Biological Diversity ◽  
High Arctic ◽  
Physical Structure ◽  
Environmental Stresses ◽  
The Arctic ◽  
Dry Valleys ◽  
Freeze Thaw ◽  
Devon Island ◽  
Order Of Magnitude ◽  
The Antarctic

We examined the environmental stresses experienced by cyanobacteria living in endolithic gneissic habitats in the Haughton impact structure, Devon Island, Canadian High Arctic (75° N) and compared them with the endolithic habitat at the opposite latitude in the Dry Valleys of Antarctica (76° S). In the Arctic during the summer, there is a period for growth of approximately 2.5 months when temperatures rise above freezing. During this period, freeze–thaw can occur during the diurnal cycle, but freeze–thaw excursions are rare within higher-frequency temperature changes on the scale of minutes, in contrast with the Antarctic Dry Valleys. In the Arctic location rainfall of approximately 3 mm can occur in a single day and provides moisture for endolithic organisms for several days afterwards. This rainfall is an order of magnitude higher than that received in the Dry Valleys over 1 year. In the Dry Valleys, endolithic communities may potentially receive higher levels of ultraviolet radiation than the Arctic location because ozone depletion is more extreme. The less extreme environmental stresses experienced in the Arctic are confirmed by the presence of substantial epilithic growth, in contrast to the Dry Valleys. Despite the more extreme conditions experienced in the Antarctic location, the diversity of organisms within the endolithic habitat, which includes lichen and eukaryotic algal components, is higher than observed at the Arctic location, where genera of cyanobacteria dominate. The lower biodiversity in the Arctic may reflect the higher water flow through the rocks caused by precipitation and the more heterogeneous physical structure of the substrate. The data illustrate an instance in which extreme climate is anti-correlated with microbial biological diversity.

scholarly journals Arctic tidal characteristics at Eureka (80° N, 86° W) and Svalbard (78° N, 16° E) for 2006/07: seasonal and longitudinal variations, migrating and non-migrating tides

2009 ◽  
Vol 27 (3) ◽  
pp. 1153-1173 ◽  
Author(s):  
A. H. Manson ◽  
C. E. Meek ◽  
T. Chshyolkova ◽  
X. Xu ◽  
T. Aso ◽  
...  
Keyword(s):  
High Arctic ◽  
Early Summer ◽  
Planetary Waves ◽  
Diurnal Tide ◽  
The Arctic ◽  
Meteor Radar ◽  
Atmospheric Propagation ◽  
Wave Numbers ◽  
The Antarctic ◽  
Abstract Operation

Abstract. Operation of a Meteor Radar at Eureka, Ellesmere Island (80° N, 86° W) began in February 2006. The first 12 months of wind data (82–97 km) are combined with winds from the Adventdalen, Svalbard Island (78° N, 16° E) Meteor Radar to provide the first contemporaneous longitudinally spaced observations of mean winds, tides and planetary waves at such high Arctic latitudes. Unique polar information on diurnal non-migrating tides (NMT) is provided, as well as complementary information to that existing for the Antarctic on the semidiurnal NMT. Zonal and meridional monthly mean winds differed significantly between Canada and Norway, indicating the influence of stationary planetary waves (SPW) in the Arctic mesopause region. Both diurnal (D) and semi-diurnal (SD) winds also demonstrated significantly different magnitudes at Eureka and Svalbard. Typically the D tide was larger at Eureka and the SD tide was larger at Svalbard. Tidal amplitudes in the Arctic were also generally larger than expected from extrapolation of high mid-latitude data. For example time-sequences from ~90 km showed D wind oscillations at Eureka of 30 m/s in February–March, and four day bursts of SD winds at Svalbard reached 40 m/s in June 2006. Fitting of wave numbers for the migrating and non-migrating tides (MT, NMT) successfully determines dominant tides for each month and height. For the diurnal tide, NMT with s=0, +2 (westward) dominate in non-summer months, while for the semi-diurnal tide NMT with s=+1, +3 occur most often during equinoctial or early summer months. These wave numbers are consistent with stationary planetary wave (SPW)-tidal interactions. Assessment of the global topographic forcing and atmospheric propagation of the SPW (S=1, 2) suggests these winter waves of the Northern Hemisphere are associated with the 78–80° N diurnal NMT, but that the SPW of the Southern Hemisphere winter have little influence on the summer Arctic tidal fields. In contrast the large SPW and NMT of the Arctic winter may be associated, consistent with Antarctic observations, with the observed occurrence of the semidiurnal NMT in the Antarctic summer.

scholarly journals Microbes in High Arctic Snow and Implications for the Cold Biosphere

2011 ◽  
Vol 77 (10) ◽  
pp. 3234-3243 ◽  
Author(s):  
Tommy Harding ◽  
Anne D. Jungblut ◽  
Connie Lovejoy ◽  
Warwick F. Vincent
Keyword(s):  
Microbial Mats ◽  
High Arctic ◽  
Small Subunit ◽  
Transport Processes ◽  
The Arctic ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
Content Type ◽  
Ssu Rrna Gene ◽  
Aerial Transport

ABSTRACTWe applied molecular, microscopic, and culture techniques to characterize the microbial communities in snow and air at remote sites in the Canadian High Arctic (Ward Hunt Island, Ellesmere Island, and Cornwallis Island, latitudes 74 to 83oN). Members of theBacteriaandEukaryawere prevalent in the snow, and their small subunit (SSU) rRNA gene signatures indicated strong local aerial transport within the region over the preceding 8 months of winter snowpack accumulation. Many of the operational taxonomic units (OTUs) were similar to previously reported SSU rRNA gene sequences from the Arctic Ocean, suggesting the importance of local aerial transport processes for marine microbiota. More than 47% of the cyanobacterial OTUs in the snow have been previously found in microbial mats in the region, indicating that this group was also substantially derived from local sources. Viable cyanobacteria isolated from the snow indicated free exchange between the snow and adjacent mat communities. Other sequences were most similar to those found outside the Canadian Arctic but were from snow, lake and sea ice, glaciers and permafrost, alpine regions, Antarctica, and other regions of the Arctic, supporting the concept of global distribution of microbial ecotypes throughout the cold biosphere.

scholarly journals Strong Seasonality of Marine Microbial Eukaryotes in a High-Arctic Fjord (Isfjorden, in West Spitsbergen, Norway)

2016 ◽  
Vol 82 (6) ◽  
pp. 1868-1880 ◽  
Author(s):  
Miriam Marquardt ◽  
Anna Vader ◽  
Eike I. Stübner ◽  
Marit Reigstad ◽  
Tove M. Gabrielsen
Keyword(s):  
454 Sequencing ◽  
High Arctic ◽  
Early Spring ◽  
Small Cells ◽  
The Arctic ◽  
Content Type ◽  
Dna And Rna ◽  
Microbial Eukaryotes ◽  
West Spitsbergen ◽  
Extreme Seasonality

ABSTRACTThe Adventfjorden time series station (IsA) in Isfjorden, West Spitsbergen, Norway, was sampled frequently from December 2011 to December 2012. The community composition of microbial eukaryotes (size, 0.45 to 10 μm) from a depth of 25 m was determined using 454 sequencing of the 18S V4 region amplified from both DNA and RNA. The compositional changes throughout the year were assessed in relation toin situfjord environmental conditions. Size fractionation analyses of chlorophyllashowed that the photosynthetic biomass was dominated by small cells (<10 μm) most of the year but that larger cells dominated during the spring and summer. The winter and early-spring communities were more diverse than the spring and summer/autumn communities. Dinophyceae were predominant throughout the year. The ArcticMicromonasecotype was abundant mostly in the early-bloom and fall periods, whereas heterotrophs, such as marine stramenopiles (MASTs), Picozoa, and the parasitoid marine alveolates (MALVs), displayed higher relative abundance in the winter than in other seasons. Our results emphasize the extreme seasonality of Arctic microbial eukaryotic communities driven by the light regime and nutrient availability but point to the necessity of a thorough knowledge of hydrography for full understanding of their succession and variability.

Description of Sphingobium psychrophilum sp. nov., a cold-adapted bacterium isolated from Arctic soil

2021 ◽  
Author(s):  
Ram Hari Dahal ◽  
Dhiraj Kumar Chaudhary ◽  
Dong-Uk Kim ◽  
Jaisoo Kim
Keyword(s):  
Type Species ◽  
Sequence Similarity ◽  
Gene Clusters ◽  
The Arctic ◽  
Rrna Gene ◽  
Respiratory Quinone ◽  
Protein Coding ◽  
Content Type ◽  
Link Type ◽  
Arctic Soil

A yellow-coloured, Gram-stain-negative, non-sporulating, psychrotolerant and motile bacterium, designated AR-3-1T, was isolated from the Arctic soil of Cambridge Bay, Nunavut, Canada. Strain AR-3-1T could grow at 4–32 °C and pH 5.0– 11.0. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain AR-3-1T formed a lineage within the family Sphingomonadaceae and clustered as a member of the genus Sphingobium . The closest members within this genus were Sphingobium cupriresistens CU4T (98.1 % sequence similarity), Sphingobium vermicomposti VC-230T (97.6 %) and Sphingobium lactosutens DS20T (97.5 %). The only respiratory quinone was the ubiquinone Q-10. Spermidine was the predominant polyamine. The principal cellular fatty acids were summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c), summed feature 3 (iso-C15  : 0 2-OH and/or C16  : 1 ω7c), C16 : 0 and C14 : 0 2-OH. The major polar lipids were phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, sphingoglycolipid and phosphoglycolipid. The DNA G+C content was 63.1 %. The average nucleotide identity and in silico DNA–DNA hybridization relatedness values between strain AR-3-1T and its most closely related genus members were ≤89.6 and 39.6 %, respectively. The genome was 5 162 327 bp long, with 83 scaffolds and 4824 protein-coding genes. The genome showed six putative biosynthetic gene clusters responsible for various secondary metabolites. Based on this polyphasic study, strain AR-3-1T represents a novel species within the genus Sphingobium , for which the name Sphingobium psychrophilum sp. nov. is proposed. The type strain is AR-3-1T (=KACC 21613T=NBRC 114604T).

scholarly journals Life in the Cold: a Proteomic Study of Cold-Repressed Proteins in the Antarctic Bacterium Pseudoalteromonas haloplanktis TAC125

2011 ◽  
Vol 77 (11) ◽  
pp. 3881-3883 ◽  
Author(s):  
Florence Piette ◽  
Salvino D'Amico ◽  
Gabriel Mazzucchelli ◽  
Antoine Danchin ◽  
Pierre Leprince ◽  
...  
Keyword(s):  
Heat Shock ◽  
Low Temperatures ◽  
Gel Electrophoresis ◽  
Two Dimensional ◽  
Content Type ◽  
Pseudoalteromonas Haloplanktis ◽  
Antarctic Bacterium ◽  
Proteomic Study ◽  
Shock Proteins ◽  
The Antarctic

ABSTRACTThe proteomes expressed at 4°C and 18°C by the psychrophilic Antarctic bacteriumPseudoalteromonas haloplanktiswere compared using two-dimensional differential in-gel electrophoresis with special reference to proteins repressed by low temperatures. Remarkably, the major cold-repressed proteins, almost undetectable at 4°C, were heat shock proteins involved in folding assistance.

scholarly journals Genome Sequence of the Arctic Methanotroph Methylobacter tundripaludum SV96

2011 ◽  
Vol 193 (22) ◽  
pp. 6418-6419 ◽  
Author(s):  
Mette M. Svenning ◽  
Anne Grethe Hestnes ◽  
Ingvild Wartiainen ◽  
Lisa Y. Stein ◽  
Martin G. Klotz ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Oxides ◽  
Novel Species ◽  
High Arctic ◽  
Nitrite Reduction ◽  
The Arctic ◽  
Wetland Soil ◽  
Content Type ◽  
Genome Data ◽  
Major Player

Methylobacter tundripaludum SV96 T (ATCC BAA-1195) is a psychrotolerant aerobic methane-oxidizing gammaproteobacterium ( Methylococcales , Methylococcaceae ) living in High Arctic wetland soil. The strain was isolated from soil harvested in July 1996 close to the settlement Ny-Ålesund, Svalbard, Norway (78°56′N, 11°53′E), and described as a novel species in 2006. The genome includes pmo and pxm operons encoding copper membrane monooxygenases (Cu-MMOs), genes required for nitrogen fixation, and the nirS gene implicated in dissimilatory nitrite reduction to NO but no identifiable inventory for further processing of nitrogen oxides. These genome data provide the basis to investigate M. tundripaludum SV96, identified as a major player in the biogeochemistry of Arctic environments.

Summer phytoplankton of the northern Barents Sea (75–80º N)

2019 ◽  
pp. 8-19
Author(s):  
Larisa A. Pautova ◽  
Vladimir A. Silkin ◽  
Marina D. Kravchishina ◽  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Weighted Average ◽  
Arctic Basin ◽  
High Arctic ◽  
Alexandrium Tamarense ◽  
Warm Water ◽  
The Arctic ◽  
Absolute Maximum ◽  
Deep Trench ◽  
Maximum Biomass

The structure of the summer planktonic communities of the Northern part of the Barents sea in the first half of August 2017 were studied. In the sea-ice melting area, the average phytoplankton biomass producing upper 50-meter layer of water reached values levels of eutrophic waters (up to 2.1 g/m3). Phytoplankton was presented by diatoms of the genera Thalassiosira and Eucampia. Maximum biomass recorded at depths of 22–52 m, the absolute maximum biomass community (5,0 g/m3) marked on the horizon of 45 m (station 5558), located at the outlet of the deep trench Franz Victoria near the West coast of the archipelago Franz Josef Land. In ice-free waters, phytoplankton abundance was low, and the weighted average biomass (8.0 mg/m3 – 123.1 mg/m3) corresponded to oligotrophic waters and lower mesotrophic waters. In the upper layers of the water population abundance was dominated by small flagellates and picoplankton from, biomass – Arctic dinoflagellates (Gymnodinium spp.) and cold Atlantic complexes (Gyrodinium lachryma, Alexandrium tamarense, Dinophysis norvegica). The proportion of Atlantic species in phytoplankton reached 75%. The representatives of warm-water Atlantic complex (Emiliania huxleyi, Rhizosolenia hebetata f. semispina, Ceratium horridum) were recorded up to 80º N, as indicators of the penetration of warm Atlantic waters into the Arctic basin. The presence of oceanic Atlantic species as warm-water and cold systems in the high Arctic indicates the strengthening of processes of “atlantificacion” in the region.

scholarly journals Draft Genome Sequence of Urease-Producing Pseudorhodobacter sp. Strain E13, Isolated from the Yellow Sea in Gunsan, South Korea

2019 ◽  
Vol 8 (23) ◽  
Author(s):  
Si Chul Kim ◽  
Hyo Jung Lee
Keyword(s):  
South Korea ◽  
Genome Sequence ◽  
Yellow Sea ◽  
Draft Genome ◽  
The Yellow Sea ◽  
Draft Genome Sequence ◽  
Protein Coding ◽  
Coding Sequences ◽  
Gram Negative ◽  
Content Type

Here, we report the draft genome sequence of Pseudorhodobacter sp. strain E13, a Gram-negative, aerobic, nonflagellated, and rod-shaped bacterium which was isolated from the Yellow Sea in South Korea. The assembled genome sequence is 3,878,578 bp long with 3,646 protein-coding sequences in 159 contigs.

scholarly journals Complete Genome Sequence of Cupriavidus necator H16 (DSM 428)

2019 ◽  
Vol 8 (37) ◽  
Author(s):  
Gareth T. Little ◽  
Muhammad Ehsaan ◽  
Christian Arenas-López ◽  
Kamran Jawed ◽  
Klaus Winzer ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Cupriavidus Necator ◽  
Rrna Genes ◽  
Trna Genes ◽  
Protein Coding ◽  
Content Type ◽  
Protein Coding Genes ◽  
Cupriavidus Necator H16

The hydrogen-utilizing strain Cupriavidus necator H16 (DSM 428) was sequenced using a combination of PacBio and Illumina sequencing. Annotation of this strain reveals 6,543 protein-coding genes, 263 pseudogenes, 64 tRNA genes, and 15 rRNA genes.

Sign in / Sign up

Export Citation Format

Share Document