UZH-Logo

Maintenance Infos

Aquatic microbial food webs


Pernthaler, J; Posch, T (2009). Aquatic microbial food webs. In: Likens, G E. Encyclopedia of Inland Waters ; vol. 3. Oxford: Elsevier, 244-251.

Abstract

Freshwater pro-and eukaryotic microorganisms and viruses are interconnected by trophic interactions that form complex food webs. The labile dissolved organic carbon in the pelagic zone is consumed by bacteria which in turn are grazed by unicellular protistan predators. This results in a recycling of growth-limiting nutrients for the phytoplankton and in the transfer of particulate organic carbon and nutrients to higher trophic levels. The success of microbial populations in aquatic environments is dependent on their ability to outgrow the mortality inflicted by protistan grazing and viral lysis while competing for limited resources. Various microbial phenotypic adaptations are therefore aimed at reducing loss rates by predation. Heterotrophic protists, in turn, selectively target particular bacterial morphotypes or species. Bacterioplankton assemblages are thus composed of different genotypic populations that are particularly well adapted to cope with either top-down (predation defense) or bottom-up (resource competition) factors. Since pelagic microbial food webs are set against a background of spatial heterogeneity, the microscale patchiness of resource distribution and mortality allows for a coexistence of bacterial species with different growth strategies. The high overall stability of aquatic prokaryotic assemblages at the community level thus probably results from the variable temporal dynamics of numerous individual bacterial populations.

Freshwater pro-and eukaryotic microorganisms and viruses are interconnected by trophic interactions that form complex food webs. The labile dissolved organic carbon in the pelagic zone is consumed by bacteria which in turn are grazed by unicellular protistan predators. This results in a recycling of growth-limiting nutrients for the phytoplankton and in the transfer of particulate organic carbon and nutrients to higher trophic levels. The success of microbial populations in aquatic environments is dependent on their ability to outgrow the mortality inflicted by protistan grazing and viral lysis while competing for limited resources. Various microbial phenotypic adaptations are therefore aimed at reducing loss rates by predation. Heterotrophic protists, in turn, selectively target particular bacterial morphotypes or species. Bacterioplankton assemblages are thus composed of different genotypic populations that are particularly well adapted to cope with either top-down (predation defense) or bottom-up (resource competition) factors. Since pelagic microbial food webs are set against a background of spatial heterogeneity, the microscale patchiness of resource distribution and mortality allows for a coexistence of bacterial species with different growth strategies. The high overall stability of aquatic prokaryotic assemblages at the community level thus probably results from the variable temporal dynamics of numerous individual bacterial populations.

Downloads

69 downloads since deposited on 21 Jan 2010
26 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Book Section, refereed, further contribution
Communities & Collections:07 Faculty of Science > Department of Plant and Microbial Biology
Dewey Decimal Classification:580 Plants (Botany)
Language:English
Date:2009
Deposited On:21 Jan 2010 17:38
Last Modified:18 Aug 2016 07:44
Publisher:Elsevier
ISBN:978-0-12-088462-9
Official URL:http://www.elsevierdirect.com/brochures/inlandwaters/index.html
Related URLs:http://opac.nebis.ch/F/?local_base=NEBIS&con_lng=GER&func=find-b&find_code=SYS&request=005817349
http://www.recherche-portal.ch/ZAD:default_scope:ebi01_prod005817349
Permanent URL: http://doi.org/10.5167/uzh-28084

Download

[img]
Preview
Content: Accepted Version
Filetype: PDF
Size: 1MB

TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.

Author Collaborations