Realisation
Our engineers have used CAD CAM and 3D printing to produce a prototype model of how our environmental solution could be devlivered in a practical, cheap, and user friendly way (left: images of prototype).
The material used for 3D printing is relatively inexpensive, especially given how little of it is needed to produce each biosensor or DCMation unit. If we had time to explore this project further, we would hope to have chance to consider how this basic model could be adapted to the different environments in which bioremediation of chlorinated solvents might be required. For example, one option we explored was the possibility of hooking the unit up to the mains water pipes in order to make filling easier, which would be ideal if the unit were on a work surface, for example in a lab. We have also thought about how our system could be scaled up for use in large factories. In our prototype, lights and clear labels have been added to make it clear to the user whether the system is safe or not yet.
In addition to cost and practicality, our design was influenced by the effectiveness of our system. For example, the biosensor has been designed in such a way as to maximize the exposure of the sensing bacteria to the solution containing GFP.
For more information, take a look at our
Biosensor Realisation and
Bioremediation Realisation and
Biopolymer Containment pages...
Above (left to right): Engineers Oliver and Leroy piece together our 3D printed prototype; Chemist Jack shows off his successful biopolymer containment; Engineer Matt completes the electrics requires for our biosensor; a close-up shot of one of Jack's 'beads'.
Cost
One of the points raised by the Environment Agency was the huge cost of simply testing for chlorinated solvent pollution, before even beginning to deal with any which is found.
The current method requires using a national network of thousands of boreholes, which are regularly sampled for numerous contaminants, including DCM and other chlorinated solvents. Initial tests give an indication of the presence of contaminants, and further tests are conducted if necessary. Tests include HPLC and mass spectroscopy. These techniques are highly expensive, costing the government hundreds of pounds per sample.
Here in the UK we are extremely fortunate to have an Agency which performs these tasks, at great expense, to protect us and our environment from chlorinated solvent waste. However, there are many places in the world where testing and decontamination procedures are far less rigorous.
We hope that development of a biosensor and bioremediation kit which is cheap and easy to manufacture would contribute to improving conditions and drinking water quality in countries which are currently unable to test for and subsequently deal with chlorinated solvent pollution due to the prohibitive cost of the processes involved.
We also hope that the ideas we develop can ultimately be applied to tackle other pollutants, using the biosensor-bioremediation-biopolymer containment mechanism technology developed by Oxford iGEM. Potential pollutants which would be suitable for bioremediation using our system can be identified by looking for other native bacteria showing a relatively high catalytic conversion rate towards these chemicals, which could be used as a basis for bioremediation in a similar way to DM4 in our DCMation system.
Safety
Safety was a primary concern when designing our system: this was further reinforced by our public engagement research which indicated how critical safety would be in securing public support and acceptance of synbio solutions. The concerns raised during the focus group discussions were at the forefront of our minds when thinking about the safety of the system.
Our public focus groups and survey results also guided our focus in the safety department. For example, members of the public were particularly concerned about escape of synthetic bacteria into the external environment. With this in mind, we designed our system using a combination of biopolymer containment and a filter to prevent the beads from being poured away inadvertently, with the effect that the bacteria cannot escape from the system.
For more information take a look at our
Safety page...
References
[1]Shaun Rowson BA (Hons) MSc CIWEM CWEM (Team Leader - Groundwater & Contaminated Land,Lincolnshire and Northamptonshire), by personal communication.