Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments

Fungal spores are ubiquitous biological aerosols, which are considered to act as ice nuclei. In this study the ice nucleation (IN) activity of spores harvested from 29 fungal strains belonging to 21 different species was tested in the immersion freezing mode by microscopic observation of water-in-oi...

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Main Authors: B. G. Pummer, L. Atanasova, H. Bauer, J. Bernardi, I. S. Druzhinina, J. Fröhlich-Nowoisky, H. Grothe
Format: Article
Language:English
Published: Copernicus Publications 2013-12-01
Series:Biogeosciences
Online Access:http://www.biogeosciences.net/10/8083/2013/bg-10-8083-2013.pdf
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author B. G. Pummer
L. Atanasova
H. Bauer
J. Bernardi
I. S. Druzhinina
J. Fröhlich-Nowoisky
H. Grothe
author_facet B. G. Pummer
L. Atanasova
H. Bauer
J. Bernardi
I. S. Druzhinina
J. Fröhlich-Nowoisky
H. Grothe
author_sort B. G. Pummer
collection DOAJ
description Fungal spores are ubiquitous biological aerosols, which are considered to act as ice nuclei. In this study the ice nucleation (IN) activity of spores harvested from 29 fungal strains belonging to 21 different species was tested in the immersion freezing mode by microscopic observation of water-in-oil emulsions. Spores of 8 of these strains were also investigated in a microdroplet freezing array instrument. The focus was laid on species of economical, ecological or sanitary significance. Besides common molds (Ascomycota), some representatives of the widespread group of mushrooms (Basidiomycota) were also investigated. <br><br> <i>Fusarium avenaceum</i> was the only sample showing IN activity at relatively high temperatures (about 264 K), while the other investigated fungal spores showed no freezing above 248 K. Many of the samples indeed froze at homogeneous ice nucleation temperatures (about 237 K). In combination with other studies, this suggests that only a limited number of species may act as atmospheric ice nuclei. This would be analogous to what is already known for the bacterial ice nuclei. <br><br> Apart from that, we selected a set of fungal strains from different sites and exposed them to occasional freezing stress during their cultivation. This was in order to test if the exposure to a cold environment encourages the expression of ice nuclei during growth as a way of adaptation. Although the total protein expression was altered by this treatment, it had no significant impact on the IN activity.
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spelling doaj.art-80e4bf338273421ba0a984a1804a1b422022-12-22T00:24:07ZengCopernicus PublicationsBiogeosciences1726-41701726-41892013-12-0110128083809110.5194/bg-10-8083-2013Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experimentsB. G. Pummer0L. Atanasova1H. Bauer2J. Bernardi3I. S. Druzhinina4J. Fröhlich-Nowoisky5H. Grothe6Institute of Materials Chemistry, Vienna University of Technology, AustriaResearch Area Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, AustriaInstitute of Chemical Technologies and Analytics, Vienna University of Technology, AustriaService Center for Transmission Electron Microscopy, Vienna University of Technology, AustriaResearch Area Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, AustriaDepartment of Multiphase Chemistry, Max Planck Institute for Chemistry, Mainz, GermanyInstitute of Materials Chemistry, Vienna University of Technology, AustriaFungal spores are ubiquitous biological aerosols, which are considered to act as ice nuclei. In this study the ice nucleation (IN) activity of spores harvested from 29 fungal strains belonging to 21 different species was tested in the immersion freezing mode by microscopic observation of water-in-oil emulsions. Spores of 8 of these strains were also investigated in a microdroplet freezing array instrument. The focus was laid on species of economical, ecological or sanitary significance. Besides common molds (Ascomycota), some representatives of the widespread group of mushrooms (Basidiomycota) were also investigated. <br><br> <i>Fusarium avenaceum</i> was the only sample showing IN activity at relatively high temperatures (about 264 K), while the other investigated fungal spores showed no freezing above 248 K. Many of the samples indeed froze at homogeneous ice nucleation temperatures (about 237 K). In combination with other studies, this suggests that only a limited number of species may act as atmospheric ice nuclei. This would be analogous to what is already known for the bacterial ice nuclei. <br><br> Apart from that, we selected a set of fungal strains from different sites and exposed them to occasional freezing stress during their cultivation. This was in order to test if the exposure to a cold environment encourages the expression of ice nuclei during growth as a way of adaptation. Although the total protein expression was altered by this treatment, it had no significant impact on the IN activity.http://www.biogeosciences.net/10/8083/2013/bg-10-8083-2013.pdf
spellingShingle B. G. Pummer
L. Atanasova
H. Bauer
J. Bernardi
I. S. Druzhinina
J. Fröhlich-Nowoisky
H. Grothe
Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments
Biogeosciences
title Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments
title_full Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments
title_fullStr Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments
title_full_unstemmed Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments
title_short Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments
title_sort spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments
url http://www.biogeosciences.net/10/8083/2013/bg-10-8083-2013.pdf
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