Bacteria

 

Marine bacterial models for experimental biology: the example of Vibrio fischeri

 

 

This online course is widely inspired and includes large extracts from a book chapter published at CRC Press, written and imagined by the same authors. We fully encourage students to read the book chapter to go further in the course and examine a broader diversity of marine bacterial models in experimental biology.

Reference :

Raphaël Lami, Régis Grimaud, Sophie Sanchez-Brosseau, Christophe Six, François Thomas, Nyree J West, Fabien Joux, Laurent Urios (2021) Marine bacterial models for experimental biology; in Established and emerging marine organisms in experimental biology. In press

 

 

Introduction

Bacteria are ubiquitous and abundant in the marine environment (105-106 cells.ml-1), playing various and diverse roles in marine ecosystems that are products of their long evolution and subsequent genetic diversification. Certain species play key roles in biogeochemical cycles, notably by contributing to primary production in the case of phototrophic Cyanobacteria, or by the remineralization of this production by heterotrophic bacteria. Other bacterial species impact human health and the economy adversely by causing disease in humans and aquaculture facilities, whereas others interact in a coordinated fashion to form biofilms that can lead to biofouling and corrosion of marine structures. Conversely, by virtue of their wide genetic diversity, the bacterial kingdom offers a chemical and enzymatic diversity that can be exploited in many fields, for example in the bioremediation of marine pollution or for the discovery of novel natural products for the food and medical industries. To further understanding in these diverse research domains, simple tractable bacterial model organisms are needed. In this on-line course, we will briefly touch on a well-known marine bacterial model organism, Vibrio fischeri, to establish some of the criteria of a good model organism.

The first short introductive videos presents a dive in the Mediterranean Sea, where a team of scientists is in search of Sepiolas living in the bay of Banyuls-sur-mer and harboring bioluminescent bacteria, including Vibrio fischeri.

The second introductive video examines what makes Vibrio fischeri is a good model in biology and announces the major lines of this on-line course.

 
 

 

 

 

 

 

 
 
 

 

 

Chapter 1:

The key features of the bacterial model Vibrio fischeri

 

 This video will introduce the marine bacterial model Vibrio fischeri and present the major physiological features of this marine bacteria.

 

 

 

Chapter 2:

Vibrio fischeri, a model to understand the mechanisms and roles of bioluminescence

The text of this video has been co-written with Sophie Sanchez-Brosseau, Assistant Professor at Sorbonne University

 

In this video, you will discover why Vibrio fischeri is a historical model to study bioluminescence, a fascinating biological phenomenon.

 

 

 
 

 

 

Chapter 3:

Vibrio fischeri, a model to understand quorum sensing circuits.

In this video, you will discover why Vibrio fischeri is the historical model to study quorum sensing, a universal and key cell-to-cell interaction mechanism which rely on the emission of small chemical compounds that synchronize a whole bacterial population.

 

 

 

 

Chapter 4:

Vibrio fischeri, a model to depict host-symbionts relationships.

The text of this video has been co-written with Sophie Sanchez-Brosseau, Assistant Professor at Sorbonne University

 

In this video, you will discover why Vibrio fischeri is a major marine model to understand at both the organismal, cellular and molecular levels the complexity of host-symbionts relationships.

 

 

 

 

Conclusions

 

You should now understand the reasons for which V. fischeri is now a well-known marine model in experimental biology. This example clearly reveals how a marine bacterial strain, which at first sight appears to have a very particular mode of life (a bacterium associated with an exotic Hawaiian species), is in fact a universal model to explore mechanisms relevant to many diverse scientific fields and is at the origin of major discoveries in biology.

 

The isolation of marine bacterial strains of interest, their full characterization, the development of genetic tools and the maintenance of strain collections, the investment in genome sequencing including accurate gene annotation, the phenotyping of mutants relying on OMICs approaches: all these steps are crucial in the establishment of new marine models in experimental biology. Thus, the example of Vibrio fischeri is only a first insight in these broader questions relative to the notion of marine bacterial models. We deeply encourage you to now read the full book chapter to go much further in this questions and to discover the diversity and interests of marine bacterial models in biology!