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Engineered bidirectional communication mediates a consensus in a microbial biofilm consortium

Brenner, Katie and Karig, David K. and Weiss, Ron and Arnold, Frances H. (2007) Engineered bidirectional communication mediates a consensus in a microbial biofilm consortium. Proceedings of the National Academy of Sciences of the United States of America, 104 (44). pp. 17300-17304. ISSN 0027-8424. PMCID PMC2077251. doi:10.1073/pnas.0704256104.

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[img] PDF (Fig. 6. Receiver A and Receiver B constructs (a) and dosage responses (b) to 3OC12HSL and C4HSL.) - Supplemental Material
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[img] PDF (Fig. 7. Computational analysis of how parameters affect whether or not YA (a) and YB (b) are thresholds that pA and pB must cross to ensure expression levels IA ³(1 + gAB)/2 and IB ³ (1 + gBA)/2.) - Supplemental Material
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[img] PDF (Fig. 8. Effect of circuit modifications upon activation by consensus. The model reveals that several key parameters can be optimized.) - Supplemental Material
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[img] PDF (Fig. 9. Plasmids encoding the MCC. In Circuit A, LasI and Target A [GFP(lva)] are under control of p(rhlA) and RBSII, while in Circuit B, RhlI and Target B (DsRed-exp) are under control of p(rsaL)-RBSII.) - Supplemental Material
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[img] PDF (Fig. 10. Fluorescence of cells containing Circuits A and B rises with time when the two are grown in communication with one another. Neither cell population fluoresces significantly in the absence of the other population.) - Supplemental Material
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[img] PDF (Fig. 11. Photograph of the flow apparatus. The entire interior was kept sterile, and flow chambers were maintained at 30°C in an incubator (not shown).) - Supplemental Material
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PDF (Table 1. Effect of system property modifications on YA/WA) - Supplemental Material
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Microbial consortia form when multiple species colocalize and communally generate a function that none is capable of alone. Consortia abound in nature, and their cooperative metabolic activities influence everything from biodiversity in the global food chain to human weight gain. Here, we present an engineered consortium in which the microbial members communicate with each other and exhibit a “consensus” gene expression response. Two colocalized populations of Escherichia coli converse bidirectionally by exchanging acyl-homoserine lactone signals. The consortium generates the gene-expression response if and only if both populations are present at sufficient cell densities. Because neither population can respond without the other's signal, this consensus function can be considered a logical AND gate in which the inputs are cell populations. The microbial consensus consortium operates in diverse growth modes, including in a biofilm, where it sustains its response for several days.

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URLURL TypeDescription CentralArticle
Arnold, Frances H.0000-0002-4027-364X
Additional Information:© 2007 by The National Academy of Sciences of the USA. Edited by Charles R. Cantor, Sequenom, Inc., San Diego, CA, and approved September 10, 2007 (received for review May 7, 2007). Published online before print October 24, 2007, doi: 10.1073/pnas.0704256104. This article is a PNAS Direct Submission. We thank Jared Leadbetter and Ernesto Andrianantoandro for discussions or comments on the manuscript; and Chris Waters, Tracy Teal, and the Caltech Biological Imaging Center for assistance with biofilm imaging. This material is based on work supported by 2005 National Science Foundation Emerging Models and Technologies for Computation Grant CCF-0523195 and 2006 National Institutes of Health Grants R01 GM074712-01A1 and 5R01CA118486-2. Author contributions: K.B. and D.K.K. contributed equally to this work; K.B., D.K.K., R.W., and F.H.A. designed research; K.B. and D.K.K. performed research; K.B. and D.K.K. contributed new reagents/analytic tools; K.B. and D.K.K. analyzed data; and K.B., D.K.K., R.W., and F.H.A. wrote the paper. The authors declare no conflict of interest. This article contains supporting information online at
Funding AgencyGrant Number
NIHR01 GM074712-01A1
Subject Keywords:biological engineering; cellular circuits; synthetic biology
Issue or Number:44
PubMed Central ID:PMC2077251
Record Number:CaltechAUTHORS:BREpnas07
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11237
Deposited By: Archive Administrator
Deposited On:26 Jul 2008 05:55
Last Modified:08 Nov 2021 21:56

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