Reference : Light induced photosynthetic electron transfer upon anaerobiosis in Chlamydomonas: Ki...
Scientific congresses and symposiums : Unpublished conference
Life sciences : Biochemistry, biophysics & molecular biology
http://hdl.handle.net/2268/126170
Light induced photosynthetic electron transfer upon anaerobiosis in Chlamydomonas: Kinetics, electron sinks and setup of a fluorescence screen to identify new players
English
Godaux, Damien [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
Emonds-Alt, Barbara mailto [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
Alric, Jean mailto []
Ghysels, Bart mailto [Université de Liège - ULg > > Labo de Bioénergétique >]
Remacle, Claire mailto [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
Cardol, Pierre mailto [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
15-Jun-2012
In Chlamydomonas reinhardtii, prolonged anaerobiosis leads to the expression of various fermentative pathways. Among them, oxygen-sensitive hydrogenases (hyd) catalyze the reduction of protons from reduced ferredoxin resulting in the production of molecular hydrogen. In this work, light-induced photosynthetic electron transfer after a prolonged dark-anaerobiosis period was studied by following the kinetics of chlorophyll fluorescence emission, P700 oxidation and proton-motive force formation and consumption during the first 3 seconds of illumination. We show that during the induction of photosynthesis, an hyd-dependent photosynthetic electron transfer operates at a maximal rate of 110 electrons per photosystem per second, that is about half the one measured in aerobiosis. The implication in this process of components of the linear, cyclic and chlororespiratory electron transfer pathways, as well as various electron sinks, are investigated thanks to the availability of mutants.
In a next step, we screen an insertional mutant library (~3000 clones) on the basis of the fluorescence induction kinetics upon a shift from dark-anaerobiosis to light. Five mutants display the signature of mutants deficient for NADPH:PQ oxidoreductase or hyd activities. In particular, one is defective for hydrogenase HydG assembly factor. This mutant behaves exactly has the hydEF mutant, thus confirming that in vivo both the assembly factors are required for an efficient hydrogenase activity.
No
International
1st international Young Algaeneers Symposium
from 14-06-2012 to 16-06-2012
Wageningen University, Bioprocess engineering laboratory
Wageningen
The Netherlands
[en] Chlamydomonas ; photosynthesis ; screening
[en] In Chlamydomonas reinhardtii, prolonged anaerobiosis leads to the expression of various fermentative pathways. Among them, oxygen-sensitive hydrogenases (hyd) catalyze the reduction of protons from reduced ferredoxin resulting in the production of molecular hydrogen. In this work, light-induced photosynthetic electron transfer after a prolonged dark-anaerobiosis period was studied by following the kinetics of chlorophyll fluorescence emission, P700 oxidation and proton-motive force formation and consumption during the first 3 seconds of illumination. We show that during the induction of photosynthesis, an hyd-dependent photosynthetic electron transfer operates at a maximal rate of 110 electrons per photosystem per second, that is about half the one measured in aerobiosis. The implication in this process of components of the linear, cyclic and chlororespiratory electron transfer pathways, as well as various electron sinks, are investigated thanks to the availability of mutants.
In a next step, we screen an insertional mutant library (~3000 clones) on the basis of the fluorescence induction kinetics upon a shift from dark-anaerobiosis to light. Five mutants display the signature of mutants deficient for NADPH:PQ oxidoreductase or hyd activities. In particular, one is defective for hydrogenase HydG assembly factor. This mutant behaves exactly has the hydEF mutant, thus confirming that in vivo both the assembly factors are required for an efficient hydrogenase activity.
Laboratoire de génétique des microorganismes
Fonds de la Recherche Scientifique (Communauté française de Belgique) - F.R.S.-FNRS
Researchers
http://hdl.handle.net/2268/126170
Présentation Orale de 20 minutes avec une scéance de questions-réponses de 10 minutes sur une partie des résultats obtenus lors de la deuxième année de ma thèse.

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Open access
Young Algaeneers symposium 2012.pdfPublisher postprint605.36 kBView/Open

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.