Date : 29/072010

Internship proposal for : Master 1 or Master 2

Laboratory
Integrative Biology Laboratory
LBI CEA-Saclay CEA
Bat142 CEA-Saclay 91191 Gif sur Yvette
Director : Franck Chauvat
Website : http://www-dsv.cea.fr/lbi
Main discipline : Molecular biologyMolecular biology

Supervisor
Franck Chauvat
email : This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
phone : +33 169087811

Subjects / Tools-Methodologies
1 : Cyanobacteria/Transcriptomics
2 : Cellular machine/Metabolomics
3 : Photoproduction of hydrogen/Interactomics

Summary of lab's interests

Photoautotrophic production of hydrogen by cyanobacteria is of great public interest in promising a clean renewable energy carrier from nature\'s most plentiful resources, solar energy and water. Previous investigations in this frame led to protocols that generate only a slight and transient increase in H2 evolution, at the expense of reduction in cell growth. Therefore, as an important milestone in the future engineering of robust cyanobacteria for industrial-level photoproduction of hydrogen we propose to (i) use our long-term (25 years; see http://publicationslist.org/franck.chauvat) experience in cyanobacterial genetics to construct robust mutants overproducing the hydrogen-evolving machine with no reduction of cell fitness; (ii) thoroughly analyze these mutants to characterize the metabolic adaptation to high-level production of H2; and (iii) use a high throughput protein-protein interaction assay for the identification of novel key players in H2 evolution.

Summary of project

As a model cyanobacterium, we will use the Synechocystis PCC6803 that combines the following advantages. Synechocystis is robust. It grows well in both fresh- and marine-waters, even at high pH that limit the growth of competing microorganisms. Synechocystis possesses a single enzyme involved in hydrogen metabolism, the bidirectional Ni-Fe pentameric hydrogenase (HoxEFUYH), encoded by weakly expressed genes. The Hox enzyme, which possesses several Fe-S clusters for electron transfer, is assembled by the six-subunits Hyp complex (HypABCDEF) that has also one Fe-S center and a zinc cofactor, thereby emphasizing on the strong connection between H2 evolution, redox metabolism and metal homeostasis. Synechocystis harbors a small fully sequenced genome (about 4.0 Mb) easily manipulable with the replicating plasmids we made for constitutive or regulated overproduction of proteins and analysis of their sub-cellular localization.