Part:BBa_K5080000
The LuxR expression system, for use in testing real milk samples.
This part is utilized to express the LuxR protein, serving as the regulatory protein in our milk detection system.
Significant research has been conducted on the Lux quorum-sensing system from Vibrio fischerii. Traditionally, the entire system was constructed on a single plasmid. This year, we have separated the two most critical components of this system: LuxR andpLux, and placed them on two distinct plasmids (corresponding to BBa_K5080001 and BBa_K5080000), creating a dual-plasmid system that responds specifically to AHL molecules, and tested this system's response to real milk samples.
Additionally, we tested the system's response to AHL small molecules under the control of the LuxR protein driven by J23119 and 16 other promoters listed in the iGEM part registry.
Part I: Standard Sample Testing
First, we tested the influence of different standards on this dual-plasmid system and obtained the AU-time curve. We then plotted a standard curve correlating the stabilized fluorescence values with the corresponding AHL small molecule concentrations.
PartII :Milk Sample Testing
Subsequently, we tested the system's response to AHL-type small molecules produced by microbial growth in actual spoiled milk samples and obtained positive results. This verified the concept of using our system for milk testing.
PartIII :High-Throughput Screening (Model Refinement)
Ultimately, we refined the entire system by replacing the promoter sequence upstream of LuxR, which yielded an extensive dataset detailing the influence of various promoter-driven LuxR expressions on the system's response intensity. Utilizing this empirical data, we developed a predictive model to elucidate the variations observed.For detailed information regarding this model, please refer to the model page on our wiki.
Reference:
[1] LuxR- and LuxI-Type Quorum-Sensing Circuits Are Prevalent in Members of the Populus deltoides Microbiome. mBio, Available at: https://doi.org/10.1128/mBio.01722-15.
[2] Odeyemi, O.A., Alegbeleye, O.O., Strateva, M. and Stratev, D. (2020) Understanding spoilage microbial community and spoilage mechanisms in foods of animal origin. Comprehensive Reviews in Food Science and Food Safety, 19, pp. 311-331. doi: 10.1111/1541-4337.12526.
[3] IIT Kharagpur iGEM Team (2015) Project Overview. Available at: https://2015.igem.org/Team:IIT_Kharagpur/Project.
[4] Tokyo Tech iGEM Team (2016) AHL Assay: AHL Reporter Assay. Available at: https://2016.igem.org/Team:Tokyo_Tech/AHL_Assay/AHL_Reporter_Assay.
[5] Michigan iGEM Team (2019) Project Overview. Available at: https://2019.igem.org/Team:Michigan/Project.
[6] GCGS China iGEM Team (2021) Project Description. Available at: https://2021.igem.org/Team:GCGS_China/Description.
[7] Kim, J., Twede, D. and Lichty, J. (1997) 'Consumer attitudes about open dating techniques for packaged foods and over-the-counter drugs', Journal of Food Products Marketing, 4(1), pp. 17-30. doi: 10.1300/J038v04n01_03.
[8] United States Food and Drug Administration (2008) Foodborne Illness-Causing Organisms in the U.S.―What You Need to Know. Available at: https://www.fda.gov/food/foodborne-pathogens/foodborne-illness-causing-organisms-us-what-you-need-know.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 7
Illegal NheI site found at 30 - 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
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