Ice nucleation activity of agricultural soil dust aerosols from Mongolia, Argentina, and Germany

Abstract. Biological residues in soil dust are a potentially strong source of atmospheric ice nuclei (IN). So far, however, the abundance, diversity, sources, seasonality, and role of biological – in particular, fungal – IN in soil dust have not been characterized. By analysis of the culturable fungi in topsoils, from a range of different land use and ecosystem types in southeast Wyoming, we found ice-nucleation-active (INA) fungi to be both widespread and abundant, particularly in soils with recent inputs of decomposable organic matter. Across all investigated soils, 8% of fungal isolates were INA. All INA isolates initiated freezing at −5 to −6 °C, and belonged to a single zygomycotic species, Mortierella alpina (Mortierellales, Mortierellomycotina). To our knowledge this is the first report of ice nucleation activity in a zygomycotic fungi because the few known INA fungi all belong to the phyla Ascomycota and Basidiomycota. M. alpina is known to be saprobic and widespread in soil, and Mortierella spores are present in air and rain. Sequencing of the ITS region and the gene for γ-linolenic elongase revealed four distinct clades, affiliated to different soil types. The IN produced by M. alpina seem to be proteinaceous, < 300 kDa in size, and can be easily washed off the mycelium. Ice nucleating fungal mycelium will ramify topsoils and probably also release cell-free IN into it. If these IN survive decomposition or are adsorbed onto mineral surfaces, their contribution might accumulate over time, perhaps to be transported with soil dust and influencing its ice nucleating properties.

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A laboratory investigation of the ice nucleation efficiency of three types of mineral and soil dust

10.5194/acp-2018-543 ◽

2018 ◽

Author(s):

Mikhail Paramonov ◽

Robert O. David ◽

Ruben Kretzschmar ◽

Zamin A. Kanji

Keyword(s):

Active Sites ◽

Particle Surface ◽

Ice Nucleation ◽

Dust Particles ◽

Bet Surface Area ◽

Soil Dust ◽

Organic Components ◽

Nucleation Activity ◽

Ice Nucleation Activity ◽

Soluble Material

Abstract. Surface-collected dust from three different locations around the world was examined with respect to its ice nucleation activity (INA) with the Portable Ice Nucleation Chamber (PINC). Ice nucleation experiments were conducted with particles of 200 and 400 nm in diameter in the temperature range of 233–243 K in both deposition nucleation and condensation freezing regimes. Several treatments were performed in order to investigate the effect of mineralogical composition, as well as the presence of biological and proteinaceous, organic and soluble compounds on the INA of mineral and soil dust. The INA of untreated dust particles correlated well with the total feldspar and K-feldspar content, corroborating previously published results. The removal of heat-sensitive proteinaceous and organic components from the particle surface with heat decreased the INA of dusts. However, the decrease in the INA was not proportional to the amount of these organic components, indicating that different proteinaceous and organic species have different ice nucleation activities, and the exact speciation is required in order to determine why dusts respond differently to the heating process. The INA of certain dusts increased after the removal of soluble material from the particle surface, demonstrating the low INA of the soluble compounds and/or the exposition of the underlying active sites. Similar to the proteinaceous organic compounds, soluble compounds seem to have different effects on the INA of surface-collected dusts, and a general conclusion about how the presence of soluble material on the particle surface affects its INA is not possible. The investigation of the heated and washed dusts revealed that mineralogy alone is not able to fully explain the observed INA of surface-collected dusts at the examined temperature and relative humidity conditions. The results showed that it is not possible to predict the INA of surface-collected soil dust based on the presence and amount of certain minerals or any particular class of compounds, such as soluble or proteinaceous/organic. Instead, at temperatures of 238–243 K the ice nucleation activity of the untreated, surface-collected soil dust in condensation freezing mode can be roughly approximated by one of the existing surrogates for atmospheric mineral dust, such as illite NX. Uncertainties associated with mechanical damage and possible changes to the mineralogy during treatments, as well as with the BET surface area and its immediate impact on the number of active sites ns,BET parameterisation, are addressed.

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Biological residues define the ice nucleation properties of soil dust

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-9643-2011 ◽

2011 ◽

Vol 11 (18) ◽

pp. 9643-9648 ◽

Cited By ~ 111

Author(s):

F. Conen ◽

C. E. Morris ◽

J. Leifeld ◽

M. V. Yakutin ◽

C. Alewell

Keyword(s):

Organic Matter ◽

Agricultural Land ◽

Size Fraction ◽

Ice Nucleation ◽

Soil Dust ◽

Ice Nuclei ◽

Mineral Dusts ◽

Nucleation Activity ◽

Micro Organisms ◽

Ice Nucleation Activity

Abstract. Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nucleation sites per unit mass active in the immersion freezing mode at −12 °C than montmorillonite, the nucleation properties of which are often used to represent those of mineral dusts in modelling studies. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

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Biological residues define the ice nucleation properties of soil dust

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-16585-2011 ◽

2011 ◽

Vol 11 (6) ◽

pp. 16585-16598 ◽

Cited By ~ 2

Author(s):

F. Conen ◽

C. E. Morris ◽

J. Leifeld ◽

M. V. Yakutin ◽

C. Alewell

Keyword(s):

Organic Matter ◽

Agricultural Land ◽

Size Fraction ◽

Ice Nucleation ◽

Global Climate Models ◽

Soil Dust ◽

Ice Nuclei ◽

Nucleation Activity ◽

Micro Organisms ◽

Ice Nucleation Activity

Abstract. Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nuclei per unit mass active in the immersion freezing mode at −12 °C than montmorillonite, the most efficient pure clay mineral. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

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Seasonal ice nucleation activity of water samples from alpine rivers and lakes in Obergurgl, Austria

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.149442 ◽

2021 ◽

pp. 149442

Author(s):

Philipp Baloh ◽

Regina Hanlon ◽

Christopher Anderson ◽

Eoin Dolan ◽

Gernot Pacholik ◽

...

Keyword(s):

Water Samples ◽

Ice Nucleation ◽

Rivers And Lakes ◽

Nucleation Activity ◽

Alpine Rivers ◽

Ice Nucleation Activity

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Ice nucleation activity of iron oxides via immersion freezing and an examination of the high ice nucleation activity of FeO

Physical Chemistry Chemical Physics ◽

10.1039/d0cp04220j ◽

2021 ◽

Vol 23 (5) ◽

pp. 3565-3573

Author(s):

Esther Chong ◽

Katherine E. Marak ◽

Yang Li ◽

Miriam Arak Freedman

Keyword(s):

Iron Oxides ◽

Functional Groups ◽

Ice Nucleation ◽

Mechanical Processing ◽

Immersion Freezing ◽

Nucleation Activity ◽

Ice Nucleation Activity

FeO has enhanced ice nucleation activity due to functional groups that are exposed upon mechanical processing.

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The occurrence of ice nucleation activity in pathogenic bacterial species

Archives of Phytopathology and Plant Protection ◽

10.1080/03235408.2012.724970 ◽

2012 ◽

Vol 45 (18) ◽

pp. 2202-2212

Author(s):

Horst Mittelstädt

Keyword(s):

Bacterial Species ◽

Ice Nucleation ◽

Nucleation Activity ◽

Ice Nucleation Activity

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Effects of atmospheric conditions on ice nucleation activity of <i>Pseudomonas</i>

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-10667-2012 ◽

2012 ◽

Vol 12 (22) ◽

pp. 10667-10677 ◽

Cited By ~ 66

Author(s):

E. Attard ◽

H. Yang ◽

A.-M. Delort ◽

P. Amato ◽

U. Pöschl ◽

...

Keyword(s):

Environmental Factors ◽

Pseudomonas Syringae ◽

Ice Nucleation ◽

Acidic Ph ◽

Bacterial Cells ◽

Atmospheric Conditions ◽

Ice Nucleation Protein ◽

Ice Melt ◽

Nucleation Activity ◽

Ice Nucleation Activity

Abstract. Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i) acidic pH (ii) NO2 and O3 exposure and (iii) UV-A exposure on the ice nucleation activity (INA) of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

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Ice nucleation activity identified in some phytopathogenic Fusarium species

Phytoprotection ◽

10.7202/706104ar ◽

2005 ◽

Vol 77 (2) ◽

pp. 83-92 ◽

Cited By ~ 29

Author(s):

C. Richard ◽

J.-G. Martin ◽

S. Pouleur

Keyword(s):

Fusarium Oxysporum ◽

Fusarium Species ◽

Freezing Temperature ◽

Ice Nucleation ◽

Free Living ◽

Factors Affecting ◽

Pure Cultures ◽

Nucleation Activity ◽

Ice Nucleation Activity ◽

Positive Controls

In order to know which species of Fusarium are ice nucleating and to determine the factors affecting their pathogenicity, ice nucleation activity (INA) was examined in Fusarium oxysporum, F. sporotrichioides, and F. tricinctum. Positive controls (lna+) used were F. acuminatum and F. avenaceum. The test for fungal INA was done with a simple and rapid tube nucleation assay. Twelve out of the 42 F. oxysporum isolates, and 8 out of 14 F. tricinctum isolates were lna+. No INA was detected in F sporotrichioides. In this test the threshold freezing temperature tended to increase with culture age, reaching a peak of -1°C in a few samples, which is as high as the warmest INA reported for bacteria, and higher than the INA detected in pure cultures of free-living fungi, lichen fungi, lichen algae and cyanobacteria. This is the first report of INA for F oxysporum.

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