We are a team of young people from different universities and different dicsiplines, creating solutions to problems that affect us directly
About Our Project
Almost Half of Kenya’s population lacks clean drinking water and this has proved to be a serious health crisis. ABSI is developing a biosensor that detects common chemical and biological contaminants that can be used by people from the comfort of their homes. The biosensor will apply common engineering principles to work, and this will be a great step for affected communities to fight waterborne illnesses
About Our Project
Project Video Description
Our circuit would be engineered to detect multiple inputs (contaminants), amplify the signal and give an accurate signal. The focus should be on both microbial and chemical contaminants. Target chemical contaminants are Cadmium, Fluoride and Lead while microbial contaminants are E.coli H. Pylori and V. cholerae. We will additionally develop a device that will scan the bacteria genome for the Multidrug Resistance genes and report accurately. Currently, we have established a Cadmium biosensor which will obtained using the assembly of artificial translationally coupled cadR operons. The incorporation of combinatorial design measurement to obtain the best the optimum performace.
Signal amplification using T7RNAP to improve sensitivity & dynamic range. Addition of Zinc exporter to improve the selectivity of CadR10 repressor.
The development of this circuit will pave way for the integration of the other circuits and thereafter a multifaceted biosensor that aligns with our initial objectives.
Engineering section Our desire is to design a biosensor with the following desired attributes of the biosensor design
- High selectivity
- Low detection limit
- Wide (output ) dynamic range
- Low leakiness
The last 3 attributes define the biosensor response curve
Our design is employing CadR.10Z ( this is a combined TF that has CadR gene + a ZitB gene that is a metal exporter that removes Zn from the cell cytoplasm thus improving selectivity). Low leakiness Low level of Cad Repressor is the design - means only low Cd ions will be needed to de -repressor the promoter to generate downstream protein expression. High level of Cad Repressor will mean that to generate downstream protein expression, then high Cd2+ ions will be needed for this to work Reducing the repressor concentration would therefore lower the specified demand on the inducer concentration, which effectively translates into a decreased LOD for the sensing module
Another strategy for improving the LOD of our biosensor could be the integration of CaDR repressor with a toggle switch. This is likely to modulate both the cadmium concentration and a LOD tuning ligand. This could be done after iGEM as we continue to work on our project. In biosensor design, if the transmembrane transporters for a ligand could be identified, the same outcome could be reproduced by overexpressing importers and knocking out exporters. For instance, disruption of the efflux transporters for Zn/Cd/Pb in P. putida strain KT2440 decreased the detection limits by up to 45-fold (Hynninen et al. 2010). In another example, an engineered E. coli biosensor achieved a lower LOD for Ni through the introduction of several foreign Ni-uptake systems
Our circuit would be engineered to detect multiple inputs (contaminants), amplify the signal and give an accurate readout signal. The focus should be on both microbial and chemical contaminants. Target chemical contaminants are Cadmium, Fluoride and Lead while microbial contaminants are E.coli H. Pylori and V. cholerae. We will additionally develop a device that will scan the bacteria genome for the Multidrug Resistance genes and report accurately. Currently, we have established a Cadmium gene circuit that is sensitive, specific and accurate. This is an improvement from the previous existing ones. Our approach focused on these 3 design principles:
- Transcription amplifier
- Multiple copy reporter gene
- Signal amplification
We applied Combinatorial Design to come up with different circuits and identify one that would yield the best performance. The work was divided into sections and handled one at a time. Therefore, we focused on: researching chemical and microbial water contaminants, market research on any available kits (none available locally), available genetic circuits of either of the contaminants of our focus and designing genetic circuits that senses and reports on cadmium contamination to identify the most sensitive and specific.Design diagrams
|Metal Pump||WP_064701588.1||Zinc Exporter|
|Polymerase 3||CadR10 + PROTEASE TAG|
|Promoter 2||Bba_J23100 series||Constitutive promoters|
|Promoter 3||BBa_J34814||T7 promoter|
|Protease tag||BBa_M0051||SsrA degradation tag|
|Repressor 2||BBa_M0051+||CadR10-protease tag|
|Strong Promoter||BBa_J23100||Anderson promoter collection|
Online research and groundwork, proved that there is currently no home-deployable biosensor in Kenya. The current field water testing kits, require certain reagents and cannot detect both chemical and microbial contaminants. This drove our interest to come up with a biosensor aimed at those living in poor conditions, those who rely on treating water, and other stakeholders to have access to clean water as they can easily test on their own and data that can inform decisions respectively.
● Ongoing publication paper (Richard’s presentation)
● Translation of (ASTWS) China team game.
Integrated Human Practices
- Participation in Inaugural International Synthetic Biology and Biosecurity Conference in Africa
- Engagement with research experts and various stakeholders.
- Engaging with Hatem. Presentation of an ongoing paper & pitch by Richard
- Synthetic Biology Conference Dec 1st
Multidisciplinary team and engagements
Team formation saw the involvement of various disciplines ranging from engineering to biology to all come experience synthetic biology as a new.
Collaboration with local universities and scientists
Through partnership and involving various stakeholders, we were introduced to other university students new to synthetic biology. This collaboration helped foster knowledge exchange and future plan on capacity building.
Ongoing publication paper (Richard’s presentation)
The focus of this paper is to show that synthetic biology cannot survive on its own. Fostering its progress and growth will require involving every single person to be informed and aware of it.
Field of Study: BSc. Biomedical Science
Field of Study: BSc. MicroBiology
Field of Study: BSc. Biomedical Science
Field of Study: BSc. Biomedical Science & Biotechnology
Wiki Page Development
Field of Study: B.Eng Chemical & Process Engineering
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Mail Us: firstname.lastname@example.org
+254 725 909775