Majority sensing in synthetic microbial consortia

Area of Science:

• Synthetic Biology
• Microbial Consortia
• Genetic Engineering

Background:

• Designing complex synthetic biocircuits for multi-strain microbial consortia is challenging.
• Predictable responses to varying consortium compositions are needed for distributed computations.

Purpose of the Study:

• To develop a two-strain gene circuit that senses and responds to the majority strain within a microbial consortium.
• To enable predictable control of gene expression based on strain ratios.

Main Methods:

• Engineered a co-repressive genetic system where each strain produces a signaling molecule.
• Implemented a system where signals down-regulate orthogonal signaling molecule production.
• Developed a mathematical model to analyze consortium dynamics and response to external induction.

Main Results:

• The gene circuit successfully links gene expression to the ratio of strains, not just population size.
• External induction was used to control the population ratio threshold for response.
• Mathematical modeling elucidated the mechanisms governing consortium dynamics.

Conclusions:

• Simple synthetic gene circuits can reliably sense and respond to the composition of microbial populations.
• This work provides a foundation for designing sophisticated distributed genetic circuits in synthetic biology.