Fate of Phaeodactylum tricornutum and nitrogen flow in an experimental microbial food web limited at the top by protozoans - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Aquatic Microbial Ecology Année : 1995

Fate of Phaeodactylum tricornutum and nitrogen flow in an experimental microbial food web limited at the top by protozoans

Résumé

The fate of phytoplankton nitrogen through a simplified microbial food web was investigated. In a 2-stage culture system, I separated production and degradation processes of a diatom, Phaeodactylum tricornutum. In the first stage, the algae grew axenically and continuously. In the second stage, maintained in the dark, a 20 pm ciliate grazed on the diatoms and constituted the last trophic step. A microbial loop, based on bacterial utilization of partially degraded P. tricornutum cells, egested with the clliate digestive vacuoles, developed rapidly. C h a t e production was maintained only because the P. tricornutum grazer was able to feed simultaneously on bacterivorous nanoflagellates, themselves preying upon bacteria using egested material of the chate. Dissolved organic nitrogen rapidly constituted more than 50% of the identified nitrogen forms (&ssolved + particulate; mineral + organic). The nitrogen budget compiled during the succession of the different prey-predator relationships revealed the important role of dissolved organic matter adsorption on particles and aggregate formation including unstable organic colloids. The temporary importance and turnover of colloidal nitrogen was thus demonstrated.
Fichier principal
Vignette du fichier
Van Wambeke 1995 AME 9 127-136.pdf (816.35 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01830024 , version 1 (04-07-2018)

Identifiants

Citer

France van Wambeke. Fate of Phaeodactylum tricornutum and nitrogen flow in an experimental microbial food web limited at the top by protozoans. Aquatic Microbial Ecology, 1995, 9, pp.127-136. ⟨10.3354/ame009127⟩. ⟨hal-01830024⟩

Collections

CNRS UNIV-AMU
59 Consultations
42 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More