Aerobiology over Antarctica – a new initiative for atmospheric ecology

The role of aerial dispersal in shaping patterns of biodiversity remains poorly understood, mainly due to a lack of coordinated efforts in gathering data at appropriate temporal and spatial scales. It has been long known that the rate of dispersal to an ecosystem can significantly influence ecosystem dynamics, and that aerial transport has been identified as an important source of biological input to remote locations. With the considerable effort devoted in recent decades to understanding atmospheric circulation in the south-polar region, a unique opportunity has emerged to investigate the atmospheric ecology of Antarctica, from regional to continental scales. This concept note identifies key questions in Antarctic microbial biogeography and the need for standardized sampling and analysis protocols to address such questions. A consortium of polar aerobiologists is established to bring together researchers with a common interest in the airborne dispersion of microbes and other propagules in the Antarctic, with opportunities for comparative studies in the Arctic

Formation during glycine-nitrate combustion and magnetic properties of YFe1–xNixO3 nanoparticles

The synthesis of FeO3 and YFe1–xNixO3 (x = 0.1; 0.15; 0.2; 0.3; 0.5) nanocrystals was performed under the conditions of a self-propagating wave of glycine-nitrate combustion and their characterization and determination of the effect of Ni2+ doping of yttrium ferrite on the magnetic properties of nanopowders. The technology for the synthesis of yttrium orthoferrite nanoparticles (with and without doping with Ni2+ ions) by the glycine-nitrate combustion method at a ratio of G/N = 1 and 1.5 without adding a gelling agent to the reaction mixture and using ethylene glycol/glycerol is described. For the characterization of nanopowders based on YFeO3, the following were determined: phase composition and crystal structure (X-ray diffraction (XRD) method); size and structure of nanocrystal particles (transmission electron microscopy (TEM)); elemental composition of the samples (local X-ray spectral microanalysis (LXSMA)); magnetic characteristics (field dependences of specific magnetization). Thermal annealing of the synthesized samples at 800°C for 60 min led to the formation of the о-YFeO3 main phase. Undoped samples of yttrium orthoferrite were characterized by a particle diameter in the range of 5-185 nm, depending on the gelling agent used. YFe1-xNixO3 particles had a predominantly round shape with a size of 24 to 31 nm; the non-monotonic dependence of the average particle diameter on the dopant content was revealed: as the amount of dopant added increased, the average crystallite size tended to decrease. Nanopowders of undoped yttrium orthoferrite exhibit antiferromagnetic behaviour of magnetic susceptibility with temperature. The change in the magnetic properties of the nickel-doped YFeO3 nanocrystalline powders was due to the incorporation of Ni2+ into the Fe3+position, which led to the formation of a material with more pronounced soft magnetic properties at a substitution degree of 0.1. Samples with high degrees of substitution (x = 0.15 and 0.3) were also characterized by paramagnetic behaviour at temperatures above 100 K

Molecularanalysis of bacterial diversity in kerosene-based drilling £uid from the deep ice borehole at Vostok, East Antarctica

Decontamination of ice cores is a critical issue in phylogenetic studies of glacial ice and subglacial lakes. At the Vostok drill site, a total of 3650 m of ice core have now been obtained from the East Antarctic ice sheet. The ice core surface is coated with a hard-to-remove film of impure drilling fluid comprising a mixture of aliphatic and aromatic hydrocarbons and foranes. In the present study we used 16S rRNA gene sequencing to analyze the bacterial content of the Vostok drilling fluid sampled from four depths in the borehole. Six phylotypes were identified in three of four samples studied. The two dominant phylotypes recovered from the deepest (3400 and 3600 m) and comparatively warm ( 10 1C and 6 1C, respectively) borehole horizons were from within the genus Sphingomonas, a well-known degrader of polyaromatic hydrocarbons. The remaining phylotypes encountered in all samples proved to be human- or soil-associated bacteria and were presumed to be drilling fluid contaminants of rare occurrence. The results obtained indicate the persistence of bacteria in extremely cold, hydrocarbon-rich environments. They show the potential for contamination of ice and subglacial water samples during lake exploration, and the need to develop a microbiological database of drilling fluid findings

Universally primed polymerase chain reaction analysis of Fusarium avenaceum isolated from wheat and barley in Finland

Selostus: Vehnästä ja ohrasta eristettyjen F. avenaceum -punahomekantojen analysointi UP-PCR-menetelmäll

Vehnästä ja ohrasta eristettyjen F. avenaceum -punahomekantojen analysointi UP-PCR-menetelmällä

Twenty-two Fusarium avenaceum isolates from Finnish wheat and barley were analysed using the chain reaction with universal primers (UP-PCR). Each isolate could be distinguished from others by UP-PCR products on polyacrylamide gels. The isolates tested were clustered into two main groups and further into several subgroups by UP-PCR profiles and phylogenetic analyses. The phylogenetic relationships of these groups are discussed. No clear correlation was found between the groups and host plant preference or the geographic origin of F. avenaceum isolates. Pathogenicity tests showed differences between F. avenaceum isolates, but two isolates, one from wheat and the other from barley, were the most aggressive in wheat and barley. This fungus, usually known as a weak pathogen of cereals and other crops, has thus probably not evolved in respect to its ability to damage wheat or barley.Suomalaisia vehnästä ja ohrasta eristettyjä punahomekantoja (Fusarium avenaceum) tutkittiin UP-PCR (Universally Primed Polymerase Chain Reaction) -menetelmällä. F. avenaceum -kannat voitiin jakaa erilaisilla foneettisilla ja fylogeneettisillä tietokoneohjelmilla kahteen pääryhmään, jotka vielä jakautuivat useaan alaryhmään. Fylogeneettisten ryhmien ja kantojen maantieteellisen jakauman välillä ei voitu havaita selvää riippuvuutta. Kannat erosivat toisistaan patogeenisuustesteissä, mutta samat ohrasta ja vehnästä eristetyt isolaatit olivat patogeenisimpiä sekä vehnällä että ohralla. Tulosten perusteella vaikuttaa siltä, että F. avenaceum, jonka tiedetään olevan suhteellisen heikko patogeeni viljakasveilla, ei ilmeisesti ole erikoistunut kumpaankaan isäntäkasviin

Universally primed polymerase chain reaction analysis of Fusarium avenaceum isolated from wheat and barley in Finland

Suomalaisia vehnästä ja ohrasta eristettyjä punahomekantoja (Fusarium avenaceum) tutkittiin UP-PCR (Universally Primed Polymerase Chain Reaction) -menetelmällä. F. avenaceum -kannat voitiin jakaa erilaisilla feneettisillä ja fylogeneettisillä tietokoneohjelmilla kahteen pääryhmään, jotka vielä jakautuivat useaan alaryhmään. Fylogeneettisten ryhmien ja kantojen maantieteellisen jakauman välillä ei voitu havaita selvää riippuvuutta. Kannat erosivat toisistaan patogeenisuustesteissä, mutta samat ohrasta ja vehnästä eristetyt isolaatit olivat patogeenisimpiä sekä vehnällä että ohralla. Tulosten perusteella vaikuttaa siltä, että F. avenaceum, jonka tiedetään olevan suhteellisen heikko patogeeni viljakasveilla, ei ilmeisesti ole erikoistunut kumpaankaan isäntäkasviin.Twenty-two Fusarium avenaceum isolates from Finnish wheat and barley were analysed using the chain reaction with universal primers (UP-PCR). Each isolate could be distinguished from others by UP-PCR products on polyacrylamide gels. The isolates tested were clustered into two main groups and further into several subgroups by UP-PCR profiles and phylogenetic analyses. The phylogenetic relationships of these groups are discussed. No clear correlation was found between the groups and host plant preference or the geographic origin of F. avenaceum isolates. Pathogenicity tests showed differences between F. avenaceum isolates, but two isolates, one from wheat and the other from barley, were the most aggressive in wheat and barley. This fungus, usually known as a weak pathogen of cereals and other crops, has thus probably not evolved in respect to its ability to damage wheat or barley.vokKirjasto Aj-kVehnästä ja ohrasta eristettyjen F. avenaceum -punahomekantojen analysointi UP-PCR-menetelmäll

Microbial communities within the water column of freshwater Lake Radok, East Antarctica: predominant 16S rDNA phylotypes and bacterial cultures

Antarctic lake ecosystems provide a rare opportunity to study the evolution and adaptation of microorganisms to extreme conditions, as well as to discover new species useful for biotechnological applications. Four water samples were collected from various layers of the water column of freshwater Lake Radok in East Antarctica. Two regions (v3-v5 and v4-v8) of the 16S rRNA gene were amplified by PCR and sequenced. Twenty dominant phylotypes were detected representing five bacterial phyla (Actinobacteria, α, β and δ Proteobacteria, Bacteroidetes, Planctomycetes, OD1) and two eukaryotic divisions (stramenopiles and green algae). Of these, 16 phylotypes demonstrated ≤98\ua0% identity to the nearest taxa in GenBank and were therefore classified as new unknown species. Seven phylotypes demonstrated ≤90\ua0% identity and thus remained unidentified. Actinobacteria was the most abundant phylum with 157 clones (41\ua0% of the total number) representing 5 phylotypes. A species complex (3 clades from acI-A subgroup) of Candidatus Planktophila limnetica was prevalent in all layers. Representatives of the OD1 phylum and δ-proteobacteria were discovered by sequencing of the v3-v5 region of 16S rRNA, while Planctomycetes, β-proteobacteria and mtDNA of stramenopiles were discovered by sequencing of the v4-v8 region. This highlights the necessity of sequencing at least two 16S rRNA gene regions to gain more data on microbial community characterization. In general, despite the uniformity in the physical and chemical properties in the water column, a prominent stratification of microbial groups was observed, at the levels of both divisions and phylotypes

Estimate for bacterial contents of 5G-1 borehole drilling fluid, Vostok station, Antarctica

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