Correlating Genomics, Proteomics and Function through 3-D cryo-TEM of Intact Environmental Microbial Cells - Luis Comolli - 10 juillet 2015

 Luis Comolli, chercheur au Lawrence Berkeley National Lab (LBNL)

Vendredi 10 juillet 2015 à 11 h

IMPMC, Université P. et M. Curie, 4, Place Jussieu, 75005 Paris

Salle de conférence - Barre 22-23 - 4^e étage - Salle 401

Abstract

Although cryogenic transmission electron microscopy (cryo-TEM) has been available for many years, it has rarely been applied to environmentally-relevant organisms. This in part due to the difficulty in preparing cryogenic TEM samples from microorganisms that cannot be cultured. Cryo-TEM has already changed our view of microbial cell architecture, and cryogenic electron tomography (cryo-ET) is becoming a more widely used technique worldwide. Consequently, there is a potential interest in using this technology as an approach to study environmental microbial systems. These systems are challenging because they are often remote, not possible to culture, difficult to transport artifact-free and intact, and ?dirty? of minerals and nanoparticles although such particles contribute to their interest. Here we demonstrate that these obstacles can be overcome. Our results include unprecedented cryo-TEM and cryo-ET image data on intact cells and microbial communities from environmental sites for which genomics and proteomics data are available. Correlative high resolution imaging of intact microbial communities integrated with metagenomics and proteomics data can help us understand metabolic states, inter-species relationships, the role of bacteriophage infections and the adaptive responses to external stress. We have established unprecedented interactions and cytoplasmic connections across species in the well characterized AMD community. These first successful applications of cryo-TEM to microorganisms within the in-situ context of their mutual interactions and extracellular minerals open the way to similar studies in many other relevant model and environmental systems in microbial ecology, Geomicrobiology, and plant or biomedical microbial communities.