Increased biosafety through cell-free systems
While developing our project idea, we were already integrating biosafety aspects in our blueprint. Last year’s Bielefeld iGEM Team was working on a biosensor for capsaicin, which is responsible for the spiciness in food. The approach was to use a test strip to get a visible light signal as a function of the sample’s spiciness. This was supposed to be a proof of principle project, but the biosensor was cell-based: This has the big disadvantage that genetically modified E. coli had to be taken out of the lab and near ones food. This constrains a possible application, because it does not only cause possible problems with biosafety but is also against the law in many countries such as Germany. Therefore, we thought that it would be great to lay the basis for cell-free biosensors.
Besides higher durability and more specific signals, cell-free biosensors have the significant advantage that for the production all GMOs stay in the controlled environment of the lab and are not taken outside the lab for the application of the biosensor. All cells are grown under controlled conditions and only qualified personnel have access to them. This minimizes the risk of releasing GMOs into the environment and therefore the possibility of horizontal gene transfer.
Expert classification of our project
To get an expert view on cell-free biosensors concerning technology assessment, biosafety and the embedment in the current discussions about synthetic biology we asked Dr. Arnold Sauter from the Office of Technology Assessment at the German Bundestag (TAB) for his opinion. Dr. Arnold Sauter is the project manager for research on synthetic biology and has a long-standing experience in technology assessment for methods and applications of genetic engineering.
The TAB is an independent scientific institution created with the objective of advising the German Bundestag and its committees on matters relating to research and technology. Since 1990 TAB, has been operated by the Institute for Technology Assessment and Systems Analysis (ITAS) of the Karlsruhe Institute for Technology (KIT), based on a contract with the German Bundestag. TAB´s steering body is the Committee on Education, Research and Technology Assessment. Since September 2003 KIT has cooperated with the Fraunhofer Institute for Systems and Innovation Research (ISI), Karlsruhe. TAB is both a member of the European Parliamentary Technology Assessment (EPTA) Network and the German language network NTA (»Netzwerk TA«) (NTA).
- “The development and use of cell-free biosensor systems for practical applications appears to be advantageous and therefore desirable in many aspects compared to genetically modified cell-based systems.
- Economic aspects: Because of approval requirements for genetically modified organisms there are probably almost insurmountable hurdles for the everyday use of cell-based systems. To my knowledge genetically modified organisms are not permitted for use outside closed systems in the EU.
- Health and environmental aspects: Potential health and ecological risks of genetically modified organisms are particularly relevant due to the uncontrolled proliferation and spread of potential living systems - which does not mean that the risks have to be large in themselves, but most of them clearly cannot be estimated or even be determined. The easiest way to avoid these risks caused by the properties of living systems (compared to dangers posed by chemicals) is to eshew organisms capable of reproduction, as in this project. Of course the necessity of a risk assessment for chemical hazards legislation persists anyway.
- Due to the possibility to “rebuild” or “design” production organisms to a much larger extent using the methods of synthetic biology than before, the problems of risk assessment and evaluation should increase significantly, because the principles of familiarity and substantial equivalence used in the past take effect to a lesser extent and thus are increasingly inapplicable.
- Therefore it makes sense to use cell-free systems wherever possible.”
Our project as an example for possible applications
To show the general public the advantages and possibilities of synthetic biology we wanted to chose an easy to understand and relevant application. Therefore we developed a biosensor for the supposedly harmful substance bisphenol A which is used in the production of polycarbonates. Hence bisphenol A can be found in a variety of objects of daily use like baby bottles, tin cans or DVDs. By providing an easy to use cell-free biosensor, bisphenol A can be detected without expensive machines or toxic substances. This project is a major step towards an application of synthetic biology and therefore a great example to show the public the advantages and possibilities of this new biotechnology branch.