POST-DOC/RESEARCH ENGINEER IN ADVANCED OPTICAL AND CRYO-ELECTRON TOMOGRAPHY IMAGING OF THE BACTERIAL CELL ENVELOPE

Institut Pasteur, France

Updated: 2 months ago
Deadline: ;

General Information

A 24-month postdoc position is available at Institut Pasteur, Paris, France. We are looking for a highly motivated candidate to study the bacterial cell envelope by cutting-edge 3D optical and cryo-electron tomography imaging.

The candidate will be working at the interface between the team of Simonetta Gribaldo , head of the Evolutionary Biology of the Microbial Cell at the Department of Microbiology, and the team of Anna Sartori-Rupp at the NanoImaging core facility of Institut Pasteur.

The Gribaldo’s lab studies the bacterial cell envelope, and particularly the transition between Gram-negatives (or diderms) and Gram-positives (or monoderms). The lab has developed a new experimental model, Veillonella parvula (diderm Firmicutes), an important anaerobic member of the human microbiome. A large range of protocols and genetic tools are available to manipulate this bacterium and characterize its envelope. Recently, a V. parvula mutant was obtained where the outer membrane is highly destabilized, opening multiple possibilities to study the diderm-to-monoderm transition in the lab. 

In collaboration with A. Sartori-Rupp, the Gribaldo’s lab has established cryo-electron tomography pipelines to provide a unique view of the bacterial cell envelope preserved as close as possible to its native state. The project will focus on visualizing for the first time the structural organization of the cell envelope in members of several bacterial lineages with nanometer scale resolution. The main aim is to create an atlas of the diversity of bacterial cell envelopes that will provide invaluable information on the transition between diderm and monoderm bacteria.

This technological project will be carried out in a stimulating multidisciplinary environment, between the Gribaldo’s research group and the Light and Cryo-Electron Microscopy imaging facilities of Institut Pasteur. The candidate will have full access to cutting-edge optical and cryo-electron microscopy infrastructure and expertise. The cryo-EM facility  of Institut Pasteur features state-of-the-art instrumentation upgraded to the latest standards for single particles and cellular studies. These include: a Titan Krios G3i Cryo-TEM equipped with a cold FEG, a SelectrisX imaging filter and a Falcon4i direct electron detector and phase plates, two Glacios with Falcon4i direct electron detectors and one with Selectris energy filter and Ceta-D camera for MicroED analysis, an Aquilos2 cryo-FIB/SEM system with cryo-lift-out and iFLM module, a Leica cryo-light Thunder Imager EM cryo-CLEM microscope & a cryo-Stellaris confocal system.

Project Description

The hired postdoc will focus on the following objectives:

  • Obtain the first high-resolution images of the cell envelope in members of different bacterial lineages presenting various sizes and shapes by using cryo-electron tomography combined with semi-automated cryo-FIB/SEM lamellae.
  • Develop fluorescence high-resolution live imaging for the model bacterium V. parvula in strict anaerobia conditions.
  • Phenotypically characterize a series of mutant strains with destabilized envelopes.

    • Requested profile

    The candidate will have a solid background and documented experience in one or several of the following fields: structural biology, electron microscopy, 3D visualization, and/or image processing and cell biology. Previous experience in bacterial cell envelopes and/or manipulation of anaerobes is welcome although not strictly necessary. We are looking for someone with a strong motivation in addressing technological challenges and open the way to methodology advancement in the relatively young field of procaryotic cell biology.

    The postdoctoral fellow will enjoy a highly interdisciplinary and collaborative environment within a group of complementary expertise and subjects (experimental/bioinformatics; Bacteria/Archaea) led by Simonetta Gribaldo and will be co-supervised by Anna Sartori-Rupp at the NanoImaging core facility (Matthijn Vos – NanoImaging Core – Research – Institut Pasteur) of Institut Pasteur.

    The position is immediately available. Benefits include comprehensive healthcare coverage for the fellow and their family, and 8 weeks paid annual leave. The Institut Pasteur is in the center of Paris, it has multiple state of-the-art facilities and constitutes a vibrant research community with 13 Departments across the Biology/Physics/Biomedical fields.

    Application

    Candidates should send a motivation letter including a brief statement of research experience, technical expertise and interest for the project, a full CV and list of publications and the contact detail of three referees to Simonetta Gribaldo & Anna Sartori-Rupp:

    [email protected]

    [email protected]

    Selected literature:

  • Megrian D, Taib N, Witwinowski J, Beloin C, Gribaldo S (2020) One or two membranes? Diderm Firmicutes challenge the Gram-positive/Gram-negative divide. Mol Microbiol 03;113(3):659-671.
  • Witwinowski J, Sartori-Rupp A, Taib N, Pende N, Tham TN, Poppleton D, Ghigo JM, Beloin C, Gribaldo S (2022) An ancient divide in outer membrane tethering systems in Bacteria suggests a mechanism for the diderm-to-monoderm transition. Nat Microbiol 7, 411–422.

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