Comparative Toxicities of Salts on Microbial Processes in Soil
| Autor: | Arpita Maheshwari, Johannes Rousk, Kristin M. Rath, Per Bengtson |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Soil salinity Potassium Sodium chemistry.chemical_element Bacterial growth Applied Microbiology and Biotechnology Microbial Ecology 03 medical and health sciences chemistry.chemical_compound Soil Soil Microbiology Ergosterol Ecology Bacteria Fungi 04 agricultural and veterinary sciences Mineralization (soil science) 030104 developmental biology chemistry Biochemistry Ionic strength Environmental chemistry 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Nitrification Salts Food Science Biotechnology |
| Popis: | Soil salinization is a growing threat to global agriculture and carbon 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, Na 2 SO 4 , and K 2 SO 4 ) to a nonsaline 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 to previous studies, nitrification was not found to be more sensitive to salt exposure than other microbial processes. The ion-specific toxicity of certain salts could be observed only for respiration, which was less inhibited by salts containing SO 4 2− than Cl − salts, in contrast to the microbial growth assessments. This suggested that the inhibition of microbial growth was explained solely by total ionic strength, while ion-specific toxicity also should be considered for effects on microbial decomposition. This difference resulted in an apparent reduction of microbial growth efficiency in response to exposure to SO 4 2− salts but not to Cl − salts; no evidence was found to distinguish K + and Na + salts. |
| Databáze: | OpenAIRE |
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