Bdellovibrio’sPrey-Independent Growth is Fuelled by Amino Acids as a Carbon Source

Abstract

ABSTRACTIdentifying the nutritional requirements and growth conditions of microorganisms is crucial for determining their applicability in industry and understanding their role in clinical ecology. Predatory bacteria such asBdellovibrio bacteriovorushave emerged as promising tools for combating infections by human bacterial pathogens due to their natural killing features.Bdellovibrio’slifecycle occurs inside prey cells, using the cytoplasm as a source of nutrients and energy. However, this lifecycle supposes a challenge when determining the specific uptake of metabolites from the prey to complete the growth inside cells, a process that has not been completely elucidated. Here, following a model-based approach we illuminate the ability ofBdellovibrio bacteriovorusto replicate DNA, increase biomass, and generate adenosine triphosphate (ATP) in an amino acid-based rich media in the absence of prey, keeping intact its predatory capacity. In this culture, we determined the main carbon sources used and their preference, being glutamate, serine, aspartate, isoleucine, and threonine. This study offers new insights into the role of predatory bacteria in natural environments and establishes the basis for developing newBdellovibrioapplications using appropriate metabolic and physiological methodologies.