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Comparative toxicity of salts to microbial processes in soil.

Rath, Kristin LU ; Maheshwari, Arpita; Bengtson, Per LU and Rousk, Johannes LU (2016) In Applied and Environmental Microbiology 82(7). p.2012-2020
Abstract
Soil salinization is a growing threat to global agriculture and carbon (C) sequestration, but to date it remains unclear how microbial processes will respond. We studied the acute response to salt exposure of a range of anabolic and catabolic microbial processes, including bacterial (leucine incorporation) and fungal (acetate incorporation into ergosterol) growth rates, respiration and gross N mineralization and nitrification rates. To distinguish effects of specific ions from those of overall ionic strength, we compared the addition of four salts frequently associated with soil salinization (NaCl, KCl, Na2SO4, K2SO4) to a non-saline soil. To compare the tolerance of different microbial processes to salt, and to interrelate the toxicity of... (More)
Soil salinization is a growing threat to global agriculture and carbon (C) sequestration, but to date it remains unclear how microbial processes will respond. We studied the acute response to salt exposure of a range of anabolic and catabolic microbial processes, including bacterial (leucine incorporation) and fungal (acetate incorporation into ergosterol) growth rates, respiration and gross N mineralization and nitrification rates. To distinguish effects of specific ions from those of overall ionic strength, we compared the addition of four salts frequently associated with soil salinization (NaCl, KCl, Na2SO4, K2SO4) to a non-saline soil. To compare the tolerance of different microbial processes to salt, and to interrelate the toxicity of different salts, concentration-response relationships were established. Growth-based measurements revealed that fungi were more resistant to salt exposure than bacteria. Effects by salt on C and N mineralization were indistinguishable and, in contrast with previous studies, nitrification was not found to be more sensitive to salt exposure than other microbial processes. Ion specific toxicity of certain salts could only be observed for respiration, which was less inhibited by salts containing SO4 (2-) than Cl(-) salts, in contrast with the microbial growth assessments. This suggested that the inhibition of microbial growth was solely explained by total ionic strength, while ionic specific toxicity should also be considered for effects on microbial decomposition. This difference resulted in an apparent reduction of microbial growth efficiency in response to exposure to SO4 (2-) salts but not to Cl(-) salts; no evidence was found to distinguish K(+) and Na(+) salts. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Applied and Environmental Microbiology
volume
82
issue
7
pages
2012 - 2020
publisher
American Society for Microbiology
external identifiers
  • pmid:26801570
  • wos:000373342400004
  • scopus:84962209798
ISSN
0099-2240
DOI
10.1128/AEM.04052-15
language
English
LU publication?
yes
id
4e7cf6b5-3510-4186-bb8e-f810acfb2f8e (old id 8574024)
date added to LUP
2016-02-16 16:11:46
date last changed
2017-09-17 03:54:17
@article{4e7cf6b5-3510-4186-bb8e-f810acfb2f8e,
  abstract     = {Soil salinization is a growing threat to global agriculture and carbon (C) sequestration, but to date it remains unclear how microbial processes will respond. We studied the acute response to salt exposure of a range of anabolic and catabolic microbial processes, including bacterial (leucine incorporation) and fungal (acetate incorporation into ergosterol) growth rates, respiration and gross N mineralization and nitrification rates. To distinguish effects of specific ions from those of overall ionic strength, we compared the addition of four salts frequently associated with soil salinization (NaCl, KCl, Na2SO4, K2SO4) to a non-saline soil. To compare the tolerance of different microbial processes to salt, and to interrelate the toxicity of different salts, concentration-response relationships were established. Growth-based measurements revealed that fungi were more resistant to salt exposure than bacteria. Effects by salt on C and N mineralization were indistinguishable and, in contrast with previous studies, nitrification was not found to be more sensitive to salt exposure than other microbial processes. Ion specific toxicity of certain salts could only be observed for respiration, which was less inhibited by salts containing SO4 (2-) than Cl(-) salts, in contrast with the microbial growth assessments. This suggested that the inhibition of microbial growth was solely explained by total ionic strength, while ionic specific toxicity should also be considered for effects on microbial decomposition. This difference resulted in an apparent reduction of microbial growth efficiency in response to exposure to SO4 (2-) salts but not to Cl(-) salts; no evidence was found to distinguish K(+) and Na(+) salts.},
  author       = {Rath, Kristin and Maheshwari, Arpita and Bengtson, Per and Rousk, Johannes},
  issn         = {0099-2240},
  language     = {eng},
  month        = {01},
  number       = {7},
  pages        = {2012--2020},
  publisher    = {American Society for Microbiology},
  series       = {Applied and Environmental Microbiology},
  title        = {Comparative toxicity of salts to microbial processes in soil.},
  url          = {http://dx.doi.org/10.1128/AEM.04052-15},
  volume       = {82},
  year         = {2016},
}