Prey bacteria shape the community structure of their predators

Area of Science:

• Microbial ecology
• Bacteriology
• Predator-prey dynamics

Background:

• Predator-prey interactions are well-studied in macroorganisms but less so in microbes.
• Bdellovibrio and like organisms (BALOs) are known bacterial predators, but selective pressures are rarely investigated.
• Understanding microbial predator-prey dynamics is crucial for ecology.

Purpose of the Study:

• To investigate selective pressures exerted by prey bacteria on predatory bacterial communities.
• To characterize the predatory behavior and population dynamics of Bacteriovorax.
• To understand how prey species influence the diversity and evolution of bacterial predators.

Main Methods:

• Environmental isolates of Bacteriovorax were fed two distinct prey species: Vibrio vulnificus and Vibrio parahaemolyticus.
• Laboratory experiments were conducted to confirm differential predation patterns.
• Phylogenetic analysis was used to examine the resulting Bacteriovorax populations.

Main Results:

• Distinct Bacteriovorax populations emerged when fed different prey species, indicating selective pressures.
• Laboratory experiments confirmed that Bacteriovorax phylotypes exhibit differential predation efficiencies on Vibrio vulnificus and Vibrio parahaemolyticus.
• Bacteriovorax Cluster IX demonstrated a versatile predatory strategy, acting as a specialist on one prey and a generalist on another, termed a 'versatilist'.

Conclusions:

• Prey bacteria significantly impact Bacteriovorax predation and shape the predator community structure.
• Bacterial predators can exhibit flexible feeding strategies, adapting to different prey availability.
• This research provides a foundation for further studies on microbial predatory behavior and ecological roles.