Periphyton as bioindicator and community model
Event details
| Date | 10.12.2013 |
| Hour | 16:15 › 17:15 |
| Speaker | Dr Alexandra Kroll, Environmental Toxicology, EAWAG, Duebendorf (CH) |
| Location | |
| Category | Conferences - Seminars |
Abstract:
Natural biofilms also known as periphyton colonize submerged surfaces in freshwater and marine ecosystems. They are taxonomically diverse and dynamic communities of bacteria, algae, and fungi that provide essential ecosystem services such as primary production, nutrient cycling and filtration of particles and pollutants.Periphyton adapts quickly to environmental conditions among others by changes in species composition.The sensitivity of periphyton to environmental conditions including anthropogenic stressors makes it an important bioindicator. However, the complexity and dynamics of these microbial communities poses a challenge to identifying appropriate descriptors, a useful level of detail and linking observed changes to understand underlying mechanisms.
Against this background we aim at establishing a tiered assessment of periphyton status using flow cytometry as first-tier followed by more detailed analysis of diversity and structure.
We are currently establishing the assessment of functional groups (by Flow cytometry), molecular diversity (community fingerprinting by ARISA), 3D structure (by Confocal laser scanning microscopy), and extracellular chemistry (by quantification of organic carbon and nitrogen compounds). An indoor colonization setup is used for long-term culturing of periphyton and exposure to chemicals. Flow cytometry and corresponding data analysis will be adapted to the characteristics of periphyton to analyze changes of functional groups (i.e. organism size, growth form, pigmentation) representing biological characteristics that are connected to ecosystem functions. This data will be linked with information on the molecular diversity and taxonomic species composition as well as structure and extracellular chemistry. Integrative endpoints such as biomass and photosynthetic activity are used to complement this information.
The talk will summarize the current state of the tiered assessment scheme and present first results on the impact of selected pesticides and nanoparticles on periphyton detected by this scheme.
Dr Alexandra Kroll's research activities aim at (1) understanding the dynamics of phototrophic organisms in periphyton (*) when exposed to low levels of new anthropogenic contaminants against the background of existing pollution and natural variations, (2) at providing efficient combinations of analysis tools for periphyton integrity on the structural and functional level, (3) and also to provide data sets that are useful to model changes in periphyton with regard to anthropogenic stressors.
(*) periphyton is an indispensible part of freshwater ecosystems which is a widely used indicator for water quality, and an important receptor for contaminants, which enhances accumulation of pollutants in the food chain.
Natural biofilms also known as periphyton colonize submerged surfaces in freshwater and marine ecosystems. They are taxonomically diverse and dynamic communities of bacteria, algae, and fungi that provide essential ecosystem services such as primary production, nutrient cycling and filtration of particles and pollutants.Periphyton adapts quickly to environmental conditions among others by changes in species composition.The sensitivity of periphyton to environmental conditions including anthropogenic stressors makes it an important bioindicator. However, the complexity and dynamics of these microbial communities poses a challenge to identifying appropriate descriptors, a useful level of detail and linking observed changes to understand underlying mechanisms.
Against this background we aim at establishing a tiered assessment of periphyton status using flow cytometry as first-tier followed by more detailed analysis of diversity and structure.
We are currently establishing the assessment of functional groups (by Flow cytometry), molecular diversity (community fingerprinting by ARISA), 3D structure (by Confocal laser scanning microscopy), and extracellular chemistry (by quantification of organic carbon and nitrogen compounds). An indoor colonization setup is used for long-term culturing of periphyton and exposure to chemicals. Flow cytometry and corresponding data analysis will be adapted to the characteristics of periphyton to analyze changes of functional groups (i.e. organism size, growth form, pigmentation) representing biological characteristics that are connected to ecosystem functions. This data will be linked with information on the molecular diversity and taxonomic species composition as well as structure and extracellular chemistry. Integrative endpoints such as biomass and photosynthetic activity are used to complement this information.
The talk will summarize the current state of the tiered assessment scheme and present first results on the impact of selected pesticides and nanoparticles on periphyton detected by this scheme.
Dr Alexandra Kroll's research activities aim at (1) understanding the dynamics of phototrophic organisms in periphyton (*) when exposed to low levels of new anthropogenic contaminants against the background of existing pollution and natural variations, (2) at providing efficient combinations of analysis tools for periphyton integrity on the structural and functional level, (3) and also to provide data sets that are useful to model changes in periphyton with regard to anthropogenic stressors.
(*) periphyton is an indispensible part of freshwater ecosystems which is a widely used indicator for water quality, and an important receptor for contaminants, which enhances accumulation of pollutants in the food chain.
Practical information
- General public
- Free
- This event is internal
Organizer
- EESS - IIE
Contact
- Prof. Samuel Arey, LMCE