Introducing THOR, a Model Microbiome for Genetic Dissection of Community Behavior

Area of Science:

• Microbiology
• Systems Biology
• Synthetic Biology

Background:

• Microbiome manipulation is challenging due to community recalcitrance.
• Understanding microbial community interactions is key to successful microbiome engineering.
• Model systems are crucial for dissecting complex biological processes.

Purpose of the Study:

• To develop a genetically tractable model microbial community for studying rhizosphere interactions.
• To investigate emergent properties and inter-species competition within a defined microbial community.
• To establish a foundation for microbiome engineering and manipulation.

Main Methods:

• Selected representatives from dominant rhizosphere taxa (Firmicutes, Proteobacteria, Bacteroidetes).
• Developed a model community (THOR) with Bacillus cereus, Pseudomonas koreensis, and Flavobacterium johnsoniae.
• Performed pairwise competition analysis and characterized emergent community properties.

Main Results:

• The THOR community exhibited emergent properties, including colony expansion and enhanced biofilm formation.
• Pseudomonas koreensis produces novel alkaloids inhibiting Flavobacterium johnsoniae growth, with inhibition modulated by Bacillus cereus.
• A hierarchical inter-strain competition network was established.

Conclusions:

• The THOR model community is amenable to genetic dissection, offering a new level of understanding of microbial community behavior.
• THOR provides a tractable system for investigating microbiome assembly, maintenance, and interactions.
• This model system can advance microbiome engineering for improved human health, agriculture, and environmental sustainability.