Shedding Light on the Cell Biology of the Predatory Bacterium Bdellovibrio bacteriovorus.

Géraldine Laloux

doi:10.3389/fmicb.2019.03136

Abstract

Bdellovibrio bacteriovorus is a predatory bacterium that feeds upon and proliferates inside other Gram-negative bacteria. Upon entry into the periplasmic space of the prey envelope, B. bacteriovorus initiates an exquisite developmental program in which it digests the host resources and grows as a filament, which eventually divides in a non-binary manner, releasing a variable number of daughter cells. The progeny then escape from the prey ghost to encounter new victims and resume the predation cycle. Owing to its unique biology, B. bacteriovorus undoubtedly represents an attractive model to unravel novel mechanisms of bacterial cell cycle control and cellular organization. Yet, the molecular factors behind the sophisticated lifestyle of this micro-predator are still mysterious. In particular, the spatiotemporal dynamics of proteins that control key cellular processes such as transmission of the genetic information, cell growth and division remain largely unexplored. In this Perspective article, I highlight outstanding fundamental questions related to these aspects and arising from the original biology of this bacterium. I also discuss available insights and potential cell biology approaches based on quantitative live imaging techniques, in combination with bacterial genetics and biochemistry, to shed light on the intracellular organization of B. bacteriovorus in space and time.

Highlights

Reviewed by: Sebastian Beck, Humboldt University of Berlin, Germany Chien-Yi Chang, University of Bradford, United Kingdom
It is likely that loci localization assays in living cells, such as the Fluorescent Reporter-Operator System (FROS) (Robinett et al, 1996; Lau et al, 2003), will reveal the position and dynamics of chromosomal loci in B. bacteriovorus, which have never been explored so far, and provide important insights into how this bacterium deals with multiple DNA replication and segregation throughout its cell cycle
Whereas evidence accumulates supporting the use of B. bacteriovorus as a potential ally against pathogenic bacteria [e.g., (Atterbury et al, 2011; Shanks et al, 2013; Tyson and Sockett, 2016; Willis et al, 2016; Im et al, 2017; McNeely et al, 2017; Findlay et al, 2019; Raghunathan et al, 2019)], there is no doubt that a fundamental understanding of its biology and the underlying molecular dynamics are absolutely needed before concretely envisioning therapeutic applications

Summary

Introduction

Reviewed by: Sebastian Beck, Humboldt University of Berlin, Germany Chien-Yi Chang, University of Bradford, United Kingdom. Cell Biology of Bdellovibrio bacteriovorus cellular events (such as DNA replication, chromosome segregation, cell growth and division) by the dynamic positioning of the corresponding regulators inside the cell is the topic of intense research (Reyes-Lamothe and Sherratt, 2019).

Results

Conclusion