Bibette, J. | bioRxiv Science

bioRxiv2023

Fatty Acid Metabolism and The Oxidative Stress Response Support Bacterial Predation

Despite growing awareness of their importance in soil ecology, the genetic and physiological traits of bacterial predators are still relatively poorly understood. In the course of a Myxococcus xanthus predator evolution experiment, we discovered a class of genotypes leading to enhanced predation against diverse species. RNA-seq analysis demonstrated that this phenotype is linked to the constitutive activation of a predation-specific program. Functional analysis of the mutations accumulated across the evolutionary time in a two- component system and Acyl-CoA-manipulating enzymes revealed the critical roles of fatty acid metabolism and antioxidant gene induction. The former likely adapts the predator to metabolites derived from the prey while the latter protects predatory cells from reactive oxygen species (ROS) generated by prey cells under stress and released upon lysis during predation. These findings reveal interesting parallels between bacterial predator-prey dynamics and pathogen-host cell interactions. Significance StatementThis study illuminates the largely unexplored genetic and metabolic strategies used by bacterial predators in soil ecosystems. Through experimental evolution in Myxococcus xanthus, we discovered that more efficient predators accumulate mutations that activate a genetic program for predation. This program simultaneously triggers a metabolic shift favoring fatty acid degradation for energy production and upregulates antioxidant gene expression, enhancing protection against reactive oxygen species generated during prey cell lysis. This adaptive mechanism proves advantageous across a wide range of prey species, suggesting that metabolic adaptation plays a crucial role in the evolutionary trajectory of bacterial predators within their natural ecological niche.

microbiology↗

bioRxiv2019

Metabolic Cost of Rapid Adaptation of Single Yeast Cells Under Unforeseen Challenge

Cells can rapidly adapt to changing environments through non-genetic processes; however, the metabolic cost of such adaptation has never been considered. Here we demonstrate metabolic coupling in a remarkable, rapid adaptation process (10-3cells/hour) by simultaneously measuring metabolism and division of thousands of individual Saccharomyces cerevisiae cells using a droplet microfluidic system. Following a severe challenge, most cells, while not dividing, continue to metabolize, displaying a remarkably wide diversity of metabolic trajectories from which adaptation events can be anticipated. Adaptation requires the consumption of a characteristic amount of energy, indicating that it is an active process. The demonstration that metabolic trajectories predict a priori adaptation events provides the first evidence of tight energetic coupling between metabolism and regulatory reorganization in adaptation.\n\nOne Sentence SummaryDemonstration of the tight coupling between metabolic activity and regulatory processes during rapid adaptation at the single-cell level.

systems biology↗