Interactions between native soil microbiome and a synthetic microbial community reveals bacteria with persistent...

Area of Science:

• Microbiology
• Synthetic Biology
• Soil Science

Background:

• Synthetic microbial communities (SynComs) offer potential for agricultural applications like enhancing plant health.
• A major challenge for SynComs is their stability and persistence when introduced into complex native soil environments.
• Understanding interactions between SynComs and native soil microbes is crucial for successful in situ applications.

Purpose of the Study:

• To investigate the survival, persistence, and chemical interactions of a SynCom with a native soil microbial community.
• To identify traits of SynCom strains that contribute to their persistence in the presence of native soil microbes.
• To assess the impact of native soil microbes on SynCom growth, viability, and metabolic activity.

Main Methods:

• Utilized a transwell system to spatially separate SynComs from native soil microbes while allowing chemical exchange.
• Composed the SynCom of six compatible Pseudomonas species, identified via whole-genome sequencing.
• Assessed SynCom interactions with native microbes using biomass and viability measurements, including flow cytometry and metabolic utilization analysis.

Main Results:

• SynCom growth was reduced in the presence of native soil microbes compared to controls.
• Flow cytometry revealed an 81% reduction in live cells, with a 78% increase in dead cells for a persistent SynCom strain.
• One persistent SynCom strain exhibited lower metabolic utilization of key compounds when exposed to native soil microbes compared to a non-persistent strain.

Conclusions:

• Native soil microbes significantly impact SynCom survival and persistence.
• Specific Pseudomonas strains possess traits that confer greater stability within complex soil ecosystems.
• Understanding these interactions is vital for optimizing SynCom design and advancing their use in agriculture.