LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 3 of total 3

Search options

  1. Article ; Online: Measurement of ice nucleation-active bacteria on plants and in precipitation by quantitative PCR.

    Hill, Thomas C J / Moffett, Bruce F / Demott, Paul J / Georgakopoulos, Dimitrios G / Stump, William L / Franc, Gary D

    Applied and environmental microbiology

    2013  Volume 80, Issue 4, Page(s) 1256–1267

    Abstract: Ice nucleation-active (INA) bacteria may function as high-temperature ice-nucleating particles (INP) in clouds, but their effective contribution to atmospheric processes, i.e., their potential to trigger glaciation and precipitation, remains uncertain. ... ...

    Abstract Ice nucleation-active (INA) bacteria may function as high-temperature ice-nucleating particles (INP) in clouds, but their effective contribution to atmospheric processes, i.e., their potential to trigger glaciation and precipitation, remains uncertain. We know little about their abundance on natural vegetation, factors that trigger their release, or persistence of their ice nucleation activity once airborne. To facilitate these investigations, we developed two quantitative PCR (qPCR) tests of the ina gene to directly count INA bacteria in environmental samples. Each of two primer pairs amplified most alleles of the ina gene and, taken together, they should amplify all known alleles. To aid primer design, we collected many new INA isolates. Alignment of their partial ina sequences revealed new and deeply branching clades, including sequences from Pseudomonas syringae pv. atropurpurea, Ps. viridiflava, Pantoea agglomerans, Xanthomonas campestris, and possibly Ps. putida, Ps. auricularis, and Ps. poae. qPCR of leaf washings recorded ∼10(8) ina genes g(-1) fresh weight of foliage on cereals and 10(5) to 10(7) g(-1) on broadleaf crops. Much lower populations were found on most naturally occurring vegetation. In fresh snow, ina genes from various INA bacteria were detected in about half the samples but at abundances that could have accounted for only a minor proportion of INP at -10°C (assuming one ina gene per INA bacterium). Despite this, an apparent biological source contributed an average of ∼85% of INP active at -10°C in snow samples. In contrast, a thunderstorm hail sample contained 0.3 INA bacteria per INP active at -10°C, suggesting a significant contribution to this sample.
    MeSH term(s) Bacteria/classification ; Bacteria/genetics ; Bacterial Load ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Molecular Sequence Data ; Plant Leaves/microbiology ; Plants/microbiology ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, DNA ; Temperature
    Chemical Substances Bacterial Outer Membrane Proteins ; Bacterial Proteins ; ice nucleation protein
    Language English
    Publishing date 2013-12-06
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 223011-2
    ISSN 1098-5336 ; 0099-2240
    ISSN (online) 1098-5336
    ISSN 0099-2240
    DOI 10.1128/AEM.02967-13
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article: Classifying atmospheric ice crystals by spatial light scattering.

    Kaye, Paul H / Hirst, Edwin / Greenaway, Richard S / Ulanowski, Zbigniew / Hesse, Evelyn / Demott, Paul J / Saunders, Clive / Connolly, Paul

    Optics letters

    2007  Volume 33, Issue 13, Page(s) 1545–1547

    Abstract: We describe preliminary results from an optical scattering instrument designed to assess the shapes and sizes of microscopic atmospheric cloud particles, especially the smallest ice crystals, that can profoundly affect cloud processes and radiative ... ...

    Abstract We describe preliminary results from an optical scattering instrument designed to assess the shapes and sizes of microscopic atmospheric cloud particles, especially the smallest ice crystals, that can profoundly affect cloud processes and radiative properties. The new instrument captures high-resolution spatial light scattering patterns from individual particles down to approximately 1 microm in size passing through a focused laser beam. Its significance lies in the ability of these patterns to provide morphological data for particle sizes well below the optical resolution limits of current cloud particle probes.
    Language English
    Publishing date 2007-09-18
    Publishing country United States
    Document type Journal Article
    ISSN 0146-9592
    ISSN 0146-9592
    DOI 10.1364/ol.33.001545
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Bringing the ocean into the laboratory to probe the chemical complexity of sea spray aerosol.

    Prather, Kimberly A / Bertram, Timothy H / Grassian, Vicki H / Deane, Grant B / Stokes, M Dale / Demott, Paul J / Aluwihare, Lihini I / Palenik, Brian P / Azam, Farooq / Seinfeld, John H / Moffet, Ryan C / Molina, Mario J / Cappa, Christopher D / Geiger, Franz M / Roberts, Gregory C / Russell, Lynn M / Ault, Andrew P / Baltrusaitis, Jonas / Collins, Douglas B /
    Corrigan, Craig E / Cuadra-Rodriguez, Luis A / Ebben, Carlena J / Forestieri, Sara D / Guasco, Timothy L / Hersey, Scott P / Kim, Michelle J / Lambert, William F / Modini, Robin L / Mui, Wilton / Pedler, Byron E / Ruppel, Matthew J / Ryder, Olivia S / Schoepp, Nathan G / Sullivan, Ryan C / Zhao, Defeng

    Proceedings of the National Academy of Sciences of the United States of America

    2013  Volume 110, Issue 19, Page(s) 7550–7555

    Abstract: The production, size, and chemical composition of sea spray aerosol (SSA) particles strongly depend on seawater chemistry, which is controlled by physical, chemical, and biological processes. Despite decades of studies in marine environments, a direct ... ...

    Abstract The production, size, and chemical composition of sea spray aerosol (SSA) particles strongly depend on seawater chemistry, which is controlled by physical, chemical, and biological processes. Despite decades of studies in marine environments, a direct relationship has yet to be established between ocean biology and the physicochemical properties of SSA. The ability to establish such relationships is hindered by the fact that SSA measurements are typically dominated by overwhelming background aerosol concentrations even in remote marine environments. Herein, we describe a newly developed approach for reproducing the chemical complexity of SSA in a laboratory setting, comprising a unique ocean-atmosphere facility equipped with actual breaking waves. A mesocosm experiment was performed in natural seawater, using controlled phytoplankton and heterotrophic bacteria concentrations, which showed SSA size and chemical mixing state are acutely sensitive to the aerosol production mechanism, as well as to the type of biological species present. The largest reduction in the hygroscopicity of SSA occurred as heterotrophic bacteria concentrations increased, whereas phytoplankton and chlorophyll-a concentrations decreased, directly corresponding to a change in mixing state in the smallest (60-180 nm) size range. Using this newly developed approach to generate realistic SSA, systematic studies can now be performed to advance our fundamental understanding of the impact of ocean biology on SSA chemical mixing state, heterogeneous reactivity, and the resulting climate-relevant properties.
    MeSH term(s) Aerosols/chemistry ; Atmosphere/chemistry ; Bacteria/metabolism ; Chlorophyll/chemistry ; Chlorophyll A ; Ecology ; Oceanography ; Oceans and Seas ; Phytoplankton/metabolism ; Seawater/chemistry
    Chemical Substances Aerosols ; Chlorophyll (1406-65-1) ; Chlorophyll A (YF5Q9EJC8Y)
    Language English
    Publishing date 2013-04-25
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.1300262110
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top