BAGEL – Bacterial Formation of Glycerol (di)Ether Lipids: Biogeochemical, (paleo)environmental and evolutionary implications

Fiche  technique du Projet

• Programme de financement: 7e PCRD – programme Personnes  – Marie Curie Actions – Intra-European Fellowships (IEF)
• Coordinateur: Université Claude Bernard Lyon 1, Dr. Vincent Grossi
• Budget Total: € 202.405,80
• Subvention : € 202.405,80
• Durée : 01/09/2013-31/08/2015

Context / Contexte

During the past decade, the structural diversity and the widespread occurrence of non-isoprenoid DGD at numerous interfaces between (recent and past) Biosphere and Geosphere has led to an intensive use of these biomarkers as proxies in biogeochemical studies. Based on their chemical structure and eventual carbon isotopic composition, the origin of non-isoprenoid DGD is arbitrarily attributed to anaerobic bacteria supposed to play a fundamental role in sulphur and/or methane cycle, in addition to the precipitation of carbonate crusts (i.e. biomineralization). However, the lack of information on the biological origin of these lipids in non-extreme environments considerably limits the scientific interpretation of the observation, thus requiring further investigation on: 1) microorganisms capable of producing these lipids, 2) the biosynthesis and the physiological role of such compounds and, 3) their modes of production (e.g. structure, distribution, stable isotopic composition) as a function of different environmental parameters (e.g. temperature, salinity, pH, phosphorous concentration).

Objectives / objectifs

This project aims at investigating in detail the first isolate of marine mesophilic sulphate-reducing bacterium able of producing non-isoprenoid DGD, and at comparing this microorganism with other bacterial strains able to produce related lipid structures. This will be achieved by combining organic geochemistry (analysis of lipid biomarkers) with microbial ecology (bacterial ecophysiology based on ultrastructure) applied to living micro-organisms. This should lead in fine to a better understanding of some biogeochemical processes occurring at many interfaces between (actual and ancient) Biosphere and Geosphere.

Impact/ results – Impact/résultats

The results of the project should have major geochemical and biochemical implications at the interface
between different scientific areas such as environmental microbiology and geochemistry. Understanding the physiological and environmental factors that control lipid biomarkers production appear as an essential step to robustly constrain the use of these molecules as biogeochemical/geological proxies. The project should also shed light on crucial aspects of microbial ecology and on the evolution of lipid biosynthesis in prokaryotes.


Le rôle de LIP 

 LIP a accompagné le porteur de projet dans toute la phase de montage et de mise en place du contrat avec la Commission Européenne.