Nutrient constraints on metabolism affect the temperature regulation of aquatic bacterial growth efficiency
Author
Summary, in English
Inorganic nutrient availability and temperature are recognized as major regulators of organic carbon processing by aquatic bacteria, but little is known about how these two factors interact to control bacterial metabolic processes. We manipulated the temperature of boreal humic stream water samples within 0-25 degrees C and measured bacterial production (BP) and respiration (BR) with and without inorganic nitrogen + phosphorus addition. Both BP and BR increased exponentially with temperature in all experiments, with Q(10) values varying between 1.2 and 2.4. The bacterial growth efficiency (BGE) showed strong negative relationships with temperature in nutrient-enriched samples and in natural stream water where community-level BP and BR were not limited by nutrients. However, there were no relationships between BGE and temperature in samples where BP and BR were significantly constrained by the inorganic nutrient availability. The results suggest that metabolic responses of aquatic bacterial communities to temperature variations can be strongly dependent on whether the bacterial metabolism is limited by inorganic nutrients or not. Such responses can have consequences for both the carbon flux through aquatic food webs and for the flux of CO(2) from aquatic systems to the atmosphere.
Publishing year
2010
Language
English
Pages
894-902
Publication/Series
Microbial Ecology
Volume
60
Issue
4
Document type
Journal article
Publisher
Springer
Topic
- Physical Geography
Keywords
- ALLOCHTHONOUS ORGANIC-CARBON
- BACTERIOPLANKTON COMMUNITIES
- TERRESTRIAL CARBON
- BOREAL CATCHMENTS
- VIRAL CONTROL
- WATER-COLUMN
- RESPIRATION
- LAKES
- PHOSPHORUS
- STREAMS
Status
Published
ISBN/ISSN/Other
- ISSN: 1432-184X