Effect of TiO2 Nanoparticles and UV Radiation on Extracellular Enzyme Activity of Intact Heterotrophic Biofilms
| Autor: | Adrian A. Ammann, Hannah Schug, Kristin Schirmer, Carl Isaacson, Laura Sigg |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Ultraviolet Rays
Heterotroph Metal Nanoparticles Aminopeptidase Water Purification Leucyl Aminopeptidase Escherichia coli Extracellular Environmental Chemistry Ecosystem Titanium chemistry.chemical_classification biology beta-Glucosidase Biofilm Biofilm matrix Heterotrophic Processes General Chemistry Alkaline Phosphatase Enzyme assay Enzyme chemistry Biochemistry Biofilms Sunlight biology.protein Nanoparticles Alkaline phosphatase Reactive Oxygen Species Water Pollutants Chemical |
| Zdroj: | Environmental Science & Technology. 48:11620-11628 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es502620e |
| Popis: | When introduced into the aquatic environment, TiO2 NP are likely to settle from the water column, which results in increased exposure of benthic communities. Here, we show that the activity of two extracellular enzymes of intact heterotrophic biofilms, β-glucosidase (carbon-cycling) and l-leucin aminopeptidase (nitrogen-cycling), was reduced following exposure to surface functionalized TiO2 NP and UV radiation, depending on the particles' coating. This reduction was partially linked to ROS production. Alkaline phosphatase (phosphorus-cycling) activity was not affected, however in contrast, an alkaline phosphatase isolated from E. coli was strongly inhibited at lower concentrations of TiO2 NP than the intact biofilms. These results indicate that enzymes present in the biofilm matrix are partly protected against exposure to TiO2 NP and UV radiation. Impairment of extracellular enzymes which mediate the uptake of nutrients from water may affect ecosystem function. |
| Databáze: | OpenAIRE |
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