Directed assembly of a bacterial quorum

Area of Science:

• Synthetic Biology
• Microbiology
• Bacterial Communication

Background:

• Bacterial quorum sensing (QS) regulates collective behaviors but quantifying participating cells is challenging.
• The precise number of cells engaging in QS (the quorum) is often unclear, obscuring benefits.
• Assembling defined quorums is difficult due to biological context dependency.

Purpose of the Study:

• To develop a method for the intentional assembly of quantized bacterial quorums.
• To engineer bacterial systems for precise control over cell density-dependent behaviors.
• To enable the study of QS benefits by controlling population fractions.

Main Methods:

• Engineered Escherichia coli (E. coli) autoinducer signal transduction pathways.
• Modified detector cells for specific autoinducer concentration sensitivity.
• Utilized DsRed expression as a marker for QS-mediated activity in emergent subpopulations.

Main Results:

• Successfully assembled quantized quorums by independently controlling signaling and sensitivity.
• Demonstrated robust QS control for both large and small quorums within approximately 6 hours.
• Achieved sensitive detection of autoinducer-2 (AI-2) using the quantized quorum system.
• Showcased sub-population partitioning, where AI-2 secreting cells recruit neighboring cells to adopt a QS phenotype.

Conclusions:

• Quantized quorums offer a novel approach to precisely control bacterial collective behavior.
• This method facilitates the study of QS mechanisms and benefits by defining participating cell numbers.
• The engineered system demonstrates potential for applications in synthetic biology and microbial engineering.