N,N-Diethyl-m-Toluamide Exposure at an Environmentally Relevant Concentration Influences River Microbial Community Development
Autor: | John R. Lawrence, Armelle Paule, Darren R. Korber, George D. W. Swerhone, Marley J. Waiser, Julie Roy |
---|---|
Rok vydání: | 2019 |
Předmět: |
0301 basic medicine
Cyanobacteria Health Toxicology and Mutagenesis 030106 microbiology DEET 010501 environmental sciences Photosynthesis 01 natural sciences 03 medical and health sciences chemistry.chemical_compound Rivers Chlorophyta RNA Ribosomal 16S Microbial community Image Processing Computer-Assisted Environmental Chemistry Animals Sequencing Biomass Protozoa 0105 earth and related environmental sciences Principal Component Analysis biology Chlorophyll A Microbiota Biofilm Environmental Exposure biology.organism_classification Environmental Toxicology Carbon Saskatchewan chemistry Microbial population biology Pigment Chlorophyll Environmental chemistry Biofilms Environmental toxicology Composition (visual arts) Temperature gradient gel electrophoresis Water Pollutants Chemical |
Zdroj: | Environmental Toxicology and Chemistry |
ISSN: | 1552-8618 |
Popis: | Studies of the South Saskatchewan River confirmed that N,N‐diethyl‐m‐toluamide (DEET) is ubiquitous at 10 to 20 ng/L, whereas in effluent‐dominated Wascana Creek, levels of 100 to 450 ng/L were observed. Effects of DEET exposure were assessed in microbial communities using a wide variety of measures. Communities developed in rotating annular reactors with either 100 or 500 ng/L DEET, verified using gas chromatography‐mass spectrometry analyses. Microscale analyses indicated that both DEET concentrations resulted in significant (p < 0.05) declines in photosynthetic biomass, whereas bacterial biomass was unaffected. There was no detectable effect of DEET on the levels of chlorophyll a. However, pigment analyses indicated substantial shifts in algal–cyanobacterial community structure, with reductions of green algae and some cyanobacterial groups at 500 ng/L DEET. Protozoan/micrometazoan grazers increased in communities exposed to 500 ng/L, but not 100 ng/L, DEET. Based on thymidine incorporation or utilization of carbon sources, DEET had no significant effects on metabolic activities. Fluorescent lectin‐binding analyses showed significant (p < 0.05) changes in glycoconjugate composition at both DEET concentrations, consistent with altered community structure. Principal component cluster analyses of denaturing gradient gel electrophoresis indicated that DEET exposure at either concentration significantly changed the bacterial community (p < 0.05). Analyses based on 16S ribosomal RNA of community composition confirmed changes with DEET exposure, increasing detectable beta‐proteobacteria, whereas actinobacteria and acidimicrobia became undetectable. Further, cyanobacteria in the subclass Oscillatoriophycideae were similarly not detected. Thus, DEET can alter microbial community structure and function, supporting the need for further evaluation of its effects in aquatic habitats. Environ Toxicol Chem 2019;38:2414–2425. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC N,N‐Diethyl‐m‐toluamide resulted in significant declines in photosynthetic biomass, whereas pigment analyses indicated changes in algal–cyanobacterial community structure. Numbers of protozoan grazers increased. DEET = N,N‐diethyl‐m‐toluamide. |
Databáze: | OpenAIRE |
Externí odkaz: |