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Effect of Aerosolization and Drying on the Viability of Pseudomonas syringae Cells

Alsved, Malin LU ; Holm, Stine; Christiansen, Sigurd; Smidt, Mads; Ling, Meilee; Boesen, Thomas; Finster, Kai; Bilde, Merete; Löndahl, Jakob LU and Šantl-Temkiv, Tina (2018) In Frontiers in Microbiology 9. p.3086-3086
Abstract

Airborne dispersal of microorganisms influences their biogeography, gene flow, atmospheric processes, human health and transmission of pathogens that affect humans, plants and animals. The extent of their impact depends essentially on cell-survival rates during the process of aerosolization. A central factor for cell-survival is water availability prior to and upon aerosolization. Also, the ability of cells to successfully cope with stress induced by drying determines their chances of survival. In this study, we used the ice-nucleation active, plant pathogenic Pseudomonas syringae strain R10.79 as a model organism to investigate the effect of drying on cell survival. Two forms of drying were simulated: drying of cells in small droplets... (More)

Airborne dispersal of microorganisms influences their biogeography, gene flow, atmospheric processes, human health and transmission of pathogens that affect humans, plants and animals. The extent of their impact depends essentially on cell-survival rates during the process of aerosolization. A central factor for cell-survival is water availability prior to and upon aerosolization. Also, the ability of cells to successfully cope with stress induced by drying determines their chances of survival. In this study, we used the ice-nucleation active, plant pathogenic Pseudomonas syringae strain R10.79 as a model organism to investigate the effect of drying on cell survival. Two forms of drying were simulated: drying of cells in small droplets aerosolized from a wet environment by bubble bursting and drying of cells in large droplets deposited on a surface. For drying of cells both in aerosol and surface droplets, the relative humidity (RH) was varied in the range between 10 and 90%. The fraction of surviving cells was determined by live/dead staining followed by flow cytometry. We also evaluated the effect of salt concentration in the water droplets on the survival of drying cells by varying the ionic strength between 0 and 700 mM using NaCl and sea salt. For both aerosol and surface drying, cell survival increased with decreasing RH (p < 0.01), and for surface drying, survival was correlated with increasing salt concentration (p < 0.001). Imaging cells with TEM showed shrunk cytoplasm and cell wall damage for a large fraction of aerosolized cells. Ultimately, we observed a 10-fold higher fraction of surviving cells when dried as aerosol compared to when dried on a surface. We conclude that the conditions, under which cells dry, significantly affect their survival and thus their success to spread through the atmosphere and colonize new environments as well as their ability to affect atmospheric processes.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bioaerosols, Aerosolization, Pseudomonas syringae, Bubble bursting, Drying, Ice nucleation activity
in
Frontiers in Microbiology
volume
9
pages
3086 - 3086
publisher
Frontiers
ISSN
1664-302X
DOI
10.3389/fmicb.2018.03086
language
English
LU publication?
yes
id
a1da9582-3dbb-4195-be36-b5a17e23d40e
date added to LUP
2019-02-22 10:11:11
date last changed
2019-06-12 02:17:34
@article{a1da9582-3dbb-4195-be36-b5a17e23d40e,
  abstract     = {<p>Airborne dispersal of microorganisms influences their biogeography, gene flow, atmospheric processes, human health and transmission of pathogens that affect humans, plants and animals. The extent of their impact depends essentially on cell-survival rates during the process of aerosolization. A central factor for cell-survival is water availability prior to and upon aerosolization. Also, the ability of cells to successfully cope with stress induced by drying determines their chances of survival. In this study, we used the ice-nucleation active, plant pathogenic Pseudomonas syringae strain R10.79 as a model organism to investigate the effect of drying on cell survival. Two forms of drying were simulated: drying of cells in small droplets aerosolized from a wet environment by bubble bursting and drying of cells in large droplets deposited on a surface. For drying of cells both in aerosol and surface droplets, the relative humidity (RH) was varied in the range between 10 and 90%. The fraction of surviving cells was determined by live/dead staining followed by flow cytometry. We also evaluated the effect of salt concentration in the water droplets on the survival of drying cells by varying the ionic strength between 0 and 700 mM using NaCl and sea salt. For both aerosol and surface drying, cell survival increased with decreasing RH (p &lt; 0.01), and for surface drying, survival was correlated with increasing salt concentration (p &lt; 0.001). Imaging cells with TEM showed shrunk cytoplasm and cell wall damage for a large fraction of aerosolized cells. Ultimately, we observed a 10-fold higher fraction of surviving cells when dried as aerosol compared to when dried on a surface. We conclude that the conditions, under which cells dry, significantly affect their survival and thus their success to spread through the atmosphere and colonize new environments as well as their ability to affect atmospheric processes.</p>},
  author       = {Alsved, Malin and Holm, Stine and Christiansen, Sigurd and Smidt, Mads and Ling, Meilee and Boesen, Thomas and Finster, Kai and Bilde, Merete and Löndahl, Jakob and Šantl-Temkiv, Tina},
  issn         = {1664-302X},
  keyword      = {Bioaerosols,Aerosolization,Pseudomonas syringae,Bubble bursting,Drying,Ice nucleation activity},
  language     = {eng},
  month        = {12},
  pages        = {3086--3086},
  publisher    = {Frontiers},
  series       = {Frontiers in Microbiology},
  title        = {Effect of Aerosolization and Drying on the Viability of Pseudomonas syringae Cells},
  url          = {http://dx.doi.org/10.3389/fmicb.2018.03086},
  volume       = {9},
  year         = {2018},
}