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Team:Edinburgh/biology(overalldescription)
From 2009.igem.org
Biology - Overall description
Personal note
Participating in the iGEM competition gives the opportunity to people to meet like-minded scientists around the world. The whole structure of the competition promotes the creation of a global scientific community, removing boundaries and making collaboration between different disciplines of science easier. Such a mentality is needed for tackling scientific issues of this era. Science has reached such a level where everyone has become so specialised, that sometimes the bigger picture is lost. Hopefully all of us can make a change for the future generations. Participating in iGEM inspired me in looking further into the beneficial prospects of synthetic biology and has motivated me to look further into this branch of science.
Vasilis
Participating in the iGEM competition gives the opportunity to people to meet like-minded scientists around the world. The whole structure of the competition promotes the creation of a global scientific community, removing boundaries and making collaboration between different disciplines of science easier. Such a mentality is needed for tackling scientific issues of this era. Science has reached such a level where everyone has become so specialised, that sometimes the bigger picture is lost. Hopefully all of us can make a change for the future generations. Participating in iGEM inspired me in looking further into the beneficial prospects of synthetic biology and has motivated me to look further into this branch of science.
Vasilis
Our project is concerned with the detection of both TNT and nitrites/ nitrates. We have designed two distinct pathways, each detecting the relevant substances. Via signal integration, both pathways interact to give a different visual signals depending on the presence or absence of our target chemicals.
In this section, we present a simplified explanation of how our system operates from a practical point of view. The first aspect to point out is that we intend for the bacteria to be spread over affected areas with an aeroplane. The resulting colour pattern will be viewed at night. The visual outcome results are summarized in Table 1.
Chemical Visual outcome
TNT Nitrates/Nitrites
Absent Absent No visual outcome
Present Absent No visual outcome
Absent Present Blue light
Present Present Yellow light
Table 1. Visual outcome in different combinations of the detected chemicals
In this section, we present a simplified explanation of how our system operates from a practical point of view. The first aspect to point out is that we intend for the bacteria to be spread over affected areas with an aeroplane. The resulting colour pattern will be viewed at night. The visual outcome results are summarized in Table 1.
You will notice that this system has a limitation – When TNT is present in the absence of nitrite, there will be no visual outcome. This is because enhanced yellow fluorescent protein (EYFP) is produced in the presence of TNT and it is not excitable by visible light. However, in the presence of nitrite/ nitrates, luciferase will produce blue light that can excite EYFP. Adding a TNT degrading enzyme to our system solves this problem. The enzyme we have incorporated is PETN reductase, a nitroreductase enzyme from Enterobacter cloacae (Accession #: U68759, Bba_xxxx). This enzyme will be produced in the presence of TNT and will degrade TNT to nitrites (French, 1998). Furthermore, TNT is degraded by naturally occurring soil flora and fauna (French, 1998). Hence, we are confident that TNT will always be present with nitrites in the soil.
Edinburgh University iGEM Team 2009
