Living Material with Temperature-Dependent Light Absorption

Area of Science:

• Synthetic biology
• Biomaterials engineering
• Microbial engineering

Background:

• Engineered living materials (ELMs) leverage biological components for advanced functionalities like self-repair.
• Escherichia coli (E. coli) are ideal for ELMs due to genetic tractability and rapid growth.
• Temperature sensitivity of E. coli growth limits ELM deployment in variable environments.

Purpose of the Study:

• To develop a temperature-responsive genetic circuit for E. coli in ELMs.
• To enable ELMs to maintain optimal performance across a range of ambient temperatures.
• To enhance the robustness and applicability of ELMs outside controlled laboratory settings.

Main Methods:

• Engineered a genetic circuit in E. coli to control chromophore expression based on temperature.
• Integrated engineered E. coli into a model planar ELM.
• Assessed bacterial growth rate and pigmentation changes at different temperatures.
• Compared engineered E. coli performance against non-pigmented and constitutively pigmented controls.

Main Results:

• Engineered E. coli increased pigmentation below 36 °C, enhancing local temperature and growth rate.
• Engineered E. coli decreased pigmentation above 36 °C, protecting growth compared to high-pigmentation controls.
• The genetic circuit successfully modulated bacterial response to thermal fluctuations within the ELM.

Conclusions:

• A novel temperature-responsive genetic circuit can optimize E. coli growth and protein production in ELMs.
• This approach mitigates challenges posed by seasonal temperature variations for ELM applications.
• ELMs integrating this technology show improved performance and broader environmental adaptability.