Herbicide-Induced Shifts in the Periphyton Community Composition Indirectly Affect Feeding Activity and Physiology of the Gastropod Grazer Physella acuta
Abstract:Herbicides are well known for unintended effects on freshwater periphyton communities. Large knowledge gaps, however, exist regarding indirect herbicide impacts on primary consumers through changes in the quality of periphyton as a food source (i.e., diet-related effects). To address this gap, the grazer Physella acuta (Gastropoda) was fed for 21 days with periphyton that grew for 15 days in the presence or absence of the herbicide diuron (8 μg/L) to quantify changes in the feeding rate, growth rate, and energ… Show more
“…The highest abundances were measured for C. polonicus and M. glauca , and the lowest one for Phormidium sp . These findings are in line with previous studies that identified these phototrophic species in either natural in situ periphyton or periphyton grown in microcosms 11 , 47 , 48 , demonstrating the ecological relevance of our synthetic microbial community. Fig.…”
Phototrophic biofilms, also known as periphyton, are microbial freshwater communities that drive crucial ecological processes in streams and lakes. Gaining a deep mechanistic understanding of the biological processes occurring in natural periphyton remains challenging due to the high complexity and variability of such communities. To address this challenge, we rationally developed a workflow to construct a synthetic community by co-culturing 26 phototrophic species (i.e., diatoms, green algae, and cyanobacteria) that were inoculated in a successional sequence to create a periphytic biofilm on glass slides. We show that this community is diverse, stable, and highly reproducible in terms of microbial composition, function, and 3D spatial structure of the biofilm. We also demonstrate the ability to monitor microbial dynamics at the single species level during periphyton development and how their abundances are impacted by stressors such as increased temperature and a herbicide, singly and in combination. Overall, such a synthetic periphyton, grown under controlled conditions, can be used as a model system for theory testing through targeted manipulation.
“…The highest abundances were measured for C. polonicus and M. glauca , and the lowest one for Phormidium sp . These findings are in line with previous studies that identified these phototrophic species in either natural in situ periphyton or periphyton grown in microcosms 11 , 47 , 48 , demonstrating the ecological relevance of our synthetic microbial community. Fig.…”
Phototrophic biofilms, also known as periphyton, are microbial freshwater communities that drive crucial ecological processes in streams and lakes. Gaining a deep mechanistic understanding of the biological processes occurring in natural periphyton remains challenging due to the high complexity and variability of such communities. To address this challenge, we rationally developed a workflow to construct a synthetic community by co-culturing 26 phototrophic species (i.e., diatoms, green algae, and cyanobacteria) that were inoculated in a successional sequence to create a periphytic biofilm on glass slides. We show that this community is diverse, stable, and highly reproducible in terms of microbial composition, function, and 3D spatial structure of the biofilm. We also demonstrate the ability to monitor microbial dynamics at the single species level during periphyton development and how their abundances are impacted by stressors such as increased temperature and a herbicide, singly and in combination. Overall, such a synthetic periphyton, grown under controlled conditions, can be used as a model system for theory testing through targeted manipulation.
“…The highest abundances were measured for C. polonicus and M. glauca, and the lowest one for Phormidium sp. These findings are in line with previous studies that identified these phototrophic species in either natural in-situ periphyton or periphyton grown in microcosms [11,47,48], demonstrating the ecological relevance of our synthetic microbial community.…”
Section: Microbial Diversity and Composition During Periphyton Establ...supporting
Phototrophic biofilms, also known as periphyton, drive crucial ecosystem processes and are subject to alterations due to a multitude of biotic and abiotic factors. In this context, understanding species dynamics in periphyton is a fundamental, yet challenging, requirement to accurately predict outcomes on functions and properties of complex communities. To address this challenge, we developed a workflow applying rational design based on existing knowledge on natural periphyton, to successfully obtain a stable, diverse and highly reproducible synthetic periphyton. We show that by using our synthetic community, with a known microbial composition, we are able to monitor dynamics of single species during periphyton development and their specific response to stressors such as increased temperature and herbicides. Importantly, we clearly demonstrate that these responses are mainly driven by species interactions and how they link to changes of community function and structure. Our synthetic periphyton is a powerful tool to perform mechanistic studies on periphyton structural and functional responses, as well as on species propagation, to any biotic and abiotic stressors and their combinations.
“…There is some evidence that herbicides may affect the FAs composition of microalgae by interfering with vegetal lipid metabolism (Demailly et al, 2019;Gonçalves et al, 2021). Herbicides may also induce changes in microorganism community structure of periphyton by selecting for more tolerant species that differ in FA composition (Konschak et al, 2021). For example, diatoms are known to be rich in EPA, while green algae are characterised by high content of ALA and bacteria by C18:1n9, C16:0 and C18:0.…”
Extensive pesticide use for agriculture diffusely pollutes aquatic ecosystems through leaching and runoff events and has the potential to negatively affect non-target organisms. Atrazine and S-metolachlor are two widely used herbicides often detected in high concentrations in rivers that drain nearby agricultural lands. To determine the effects of these two herbicides on river ecosystems, we conducted a 14-day laboratory experiment to expose river periphyton to a wide range of atrazine and S-metolachlor concentrations. The response of periphyton was evaluated using ecologically relevant endpoints including chlorophyll a uorescence and fatty acids composition. Results showed that atrazine disrupted photoautotroph biomass measured by chlorophyll a uorescence. Both herbicides caused dissimilarities in fatty acid pro les between control and high exposure concentrations, but S-metolachlor had a stronger effect than atrazine on the observe increase or reduction in saturated fatty acids (SFAs) and very long chain fatty acids (VLCFAs). Our study demonstrates that two commonly used herbicides, atrazine and S-metolachlor, can negatively affect the composition and fatty acid pro les of stream periphyton, thereby altering the nutritional quality of this resource for primary consumers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
