Assessing the role of phytoplankton-bacterioplankton coupling in the response of microbial plankton to nutrient additions

• Microbial plankton communities do not always respond to inorganic nutrient additions in coastal waters off NW Spain. However, enhanced growth of phytoplankton and heterotrophic bacteria has been observed when exposed to both inorganic (nitrate, ammonium and phosphate) and organic (amino acids and glucose) nutrient amendments, suggesting the existence of a coupling between both microbial compartments. The aim of this paper was to assess the role of the phytoplankton-bacterioplankton coupling in the response of primary producers to nutrient additions. Changes in bacterial production (BP), primary production, and chlorophyll a concentration were measured after different nutrient addition treatments on natural microbial communities where bacterial activity was blocked with antibiotics. The results obtained in this study show that phytoplankton biomass and production respond only to the nutrient inputs when heterotrophic bacteria are active. The response of coastal microbial plankton to nutrient inputs might thus be eventually dependent on the BP of secondary metabolites necessary for phytoplankton growth (e.g. B-12 vitamin).

Ämnesord

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Nyckelord

phytoplankton

bacteria

coupling

antibiotic

vitamin

nutrient addition

Akvatisk ekologi

Aquatic Ecology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)