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Self-regulating living material with temperature-dependent light absorption

Xiong, Lealia L. and Garrett, Michael A. and Kornfield, Julia A. and Shapiro, Mikhail G. (2023) Self-regulating living material with temperature-dependent light absorption. . (Unpublished)

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Engineered living materials (ELMs) exhibit desirable characteristics of the living component, including growth and repair, and responsiveness to external stimuli. Escherichia coli are a promising constituent of ELMs because they are very tractable to genetic engineering, produce heterologous proteins readily, and grow exponentially. However, seasonal variation in ambient temperature presents a challenge in deploying ELMs outside of a laboratory environment, because E. coli growth rate is impaired both below and above 37°C. Here, we develop a genetically-encoded mechanism for autonomous temperature homeostasis in ELMs containing E. coli by engineering circuits that control the expression of a light-absorptive chromophore in response to changes in temperature. We demonstrate that below 36°C, our engineered E. coli increase in pigmentation, causing an increase in sample temperature and growth rate above non-pigmented counterparts in a model planar ELM. On the other hand, above 36°C, they decrease in pigmentation, protecting their growth compared to bacteria with temperature-independent high pigmentation. Integrating our temperature homeostasis circuit into an ELM has the potential to improve living material performance by optimizing growth and protein production in the face of seasonal temperature changes.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Xiong, Lealia L.0000-0001-7636-5936
Kornfield, Julia A.0000-0001-6746-8634
Shapiro, Mikhail G.0000-0002-0291-4215
Additional Information:The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. The authors thank Hanwei Liu, David Tirrell, Priya Chittur, and Seunghyun Sim for helpful discussions about engineered living materials, as well as Red Lhota, Robert Learsch, and Justin Bois for assistance with instrument design. This research was supported by the Defense Advanced Research Project Agency (HR0011-17-2-0037 to M.G.S. and J.A.K.), the Institute for Collaborative Biotechnologies (W911NF-19- D-0001 to M.G.S.), the Jacobs Institute for Molecular Engineering for Medicine (to J.A.K.), and the Elizabeth W. Gilloon Chair (to J.A.K.). L.L.X. was supported by the NSF Graduate Research Fellowship Program. M.A.G. was supported by the NIH MBRS Research Initiative for Scientific Enhancement Program. M.G.S. is an Investigator of the Howard Hughes Medical Institute. Related research in the Shapiro lab is supported by the David and Lucile Packard Foundation and the Dreyfus Foundation. AUTHOR CONTRIBUTIONS. L.L.X. and M.G.S. conceived the study. L.L.X. and M.A.G. planned and performed experiments. L.L.X. analyzed data. J. A. K. provided input on research design and data interpretation. L.L.X. and M.G.S. wrote the manuscript with input from all other authors. M.G.S. and J.A.K. supervised the research. The authors have declared no competing interest.
Group:Jacobs Institute for Molecular Engineering for Medicine
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)HR0011-17-2-0037
Army Research Office (ARO)W911NF-19-D-0001
Jacobs Institute for Molecular Engineering for MedicineUNSPECIFIED
Elizabeth W. Gilloon Professor of Chemical EngineeringUNSPECIFIED
NSF Graduate Research FellowshipUNSPECIFIED
Howard Hughes Medical Institute (HHMI)UNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Camille and Henry Dreyfus FoundationUNSPECIFIED
Record Number:CaltechAUTHORS:20230316-181929000.6
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:120125
Deposited By: George Porter
Deposited On:22 Mar 2023 16:54
Last Modified:22 Mar 2023 16:54

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