Nutrient constraints on metabolism affect the temperature regulation of aquatic bacterial growth efficiency

Research output: Contribution to journalArticle

Abstract

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.

Details

Authors
External organisations
  • Swedish University of Agricultural Sciences
  • Umeå University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Geography

Keywords

  • ALLOCHTHONOUS ORGANIC-CARBON, BACTERIOPLANKTON COMMUNITIES, TERRESTRIAL CARBON, BOREAL CATCHMENTS, VIRAL CONTROL, WATER-COLUMN, RESPIRATION, LAKES, PHOSPHORUS, STREAMS
Original languageEnglish
Pages (from-to)894-902
JournalMicrobial Ecology
Volume60
Issue number4
Publication statusPublished - 2010
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes