Team:Manchester/Human Practices



    We engaged with a diverse group of people when investigating the impacts that a food-based biosensor may have. Contacting cheese manufacturers in the UK and EU highlighted a requirement for a Listeria detection system to find contamination early in the food production process, so we aimed to incorporate a biosensor into the first step of manufacture: the cheese starter culture. Through outreach activities with the general public we investigated consumer preference on live GMOs in food and found using a strain native to cheese was preferred, so we designed Listeria-detecting BioBricks compatible with lactic acid bacteria L. lactis. Following consultation with the European Commission for Health and Food Safety, we analysed the current and future legal framework around live GMOs in food to learn whether our project could be used in the EU. This prompted us to investigate through modelling whether a cell-free biosensor might be a better alternative.


We first realised that we needed to investigate the scale of the Listeria problem, and so began our human practices investigating the impact of Listeria outbreaks worldwide in the last year.
We found that:

  • Listeria has an effect on trade, both directly (via restrictions on import from affected countries) and indirectly (due to loss of consumer trust and reduced demand for goods).

  • We need to ensure that our detection system is both quick and accurate to avoid lost time waiting for tests impacting the quality of the food being tested.

  • It is key that food testing be decentralised to avoid a single point of failure and therefore our detection system should use a reporter that needs no equipment to interpret.

  • It is currently impractical to test each packet of food if contamination is suspected. Our system needs to be higher resolution by reporting Listeria contamination only when present and able to prevent this food waste.

  • We began planning a Listeria detection system using easily-visible chromoproteins as the output.


  • When we learned more about the problems with Listeria contamination in food we were eager to learn more about the cheesemaking industry tackles this problem. We first visited a local cheese maker Claire Burt to get to know about the cheese making process and a local cheesemaker’s perspective about our idea.

  • We found that the commercial cheese making process is very sensitive and needs to be highly controlled.

  • Claire explained to us that Listeria contamination can occur in the very first stages of cheese production, which indicated to us that having a biosensor which could detect contamination in these early stages (i.e., by being incorporated into cheese starter culture) would be invaluable. She also told us that there is possibility for contamination on various surfaces or water used in the process. That suggested to us that having a cell-free or an isolated-cell test would be more convenient than a biosensor integrated into the product. Hearing that, we started modelling an isolated-cell system to be able to predict how quickly such test could detect pathogenic bacteria (read more).


In our early search for council, we contacted Michael Mullen of ‘Dairy Science Food Technology’. On hearing the details of our project he expressed significant concern about the legality or commercial viability of our project, stating that:

“this has limited practical application and if I were the expert assessor I would voice my concerns. Currently, we are not legally permitted to use genetically engineered cultures in cheese making”

and that it is

“not practical in our current legislative environment and would be unlikely to be looked on favourably by consumers either”.

As our first piece of significant negative feedback on our project, we took this criticism very seriously. On receiving further confirmation that the selling of a product such as ours would be prevented by legislation, we were further prompted to look further into current EU laws surrounding the deliberate release of GMOs (read more). Mr. Mullen’s concerns about the consumer opinion of our novel starter culture also worried us. We decided that we needed to deliver an outreach event at The Manchester Museum to see if Mr. Mullen’s prediction about our products lack of commercial viability was correct (read more).


  • We hosted a small stand in The Manchester Museum as part of ‘University of Manchester Community Fest’.

  • We introduced members of the general public to our project idea and asked if they would eat a cheese that contains GMOs if the purpose of GMOs is to detect the pathogenic bacteria. The majority of people showed an interest to our approach and supported the idea saying that they would not mind GM bacteria in cheese if it is safe to eat.

  • From our input from Claire Burt, we had already been thinking of incorporating a live genetically-modified bacteria into cheese starter cultures. Early in the project design we were considering using modified E. coli (Nissle 1917), a probiotic strain. From feedback in this outreach session we realised that people's awareness of E. coli is more as a pathogen and people would, therefore, prefer any GMOs in food to be a strain native to that food. We chose to use L. lactis, known as 'good bacteria', to be integrated into our product.


    We then decided to ask another cheesemaker for feedback. As our project is designed to make cheese products safer, we need to examine the suggestions of multiple cheesemakers because they are the experts and so can advise us on our project design.

    We arranged a phone talk with Vadimas Kličius, the director of new product development in “Rokiškio sūris” (a major cheese manufacturer in Lithuania) and discussed our project idea.

    The takeout message from the talk was that mesophilic L. lactis bacteria culture is not an optimal choice for the biosensor. The bacteria culture could not be used in making hard cheeses and some of the soft cheeses, that we are aiming for this project, do not use L. lactis in the making process. To improve our project design, we have optimised codon sequences for a thermophilic bacteria Streptococcus thermophilus. Though we did not have time to test these in the laboratory during our iGEM project, we have made these sequences available for teams if they wished to continue our work.

    Also, Vadimas mentioned that GMOs in cheese are not currently accepted and that the perception of GMOs would be the main issue in applying our biosensor in any cheese making company. This is why we are modelling the isolated cell detection system so we would not need to integrate modified L. lactis to cheese products (read more). We also decided that we needed to look deeper into the legislation behind GMOs in food, and so we were inspired to begin discussions with the European Commission about current GMO regulations and their impact on our project (read more).


  • After speaking with Michael Mullen and Vadimas Kličius, we decided we should investigate GMOs and EU law. As we are in the United Kingdom, we thought it might be interesting to investigate current literature about how laws about GMOs in food might change after Britain leaves the EU in March 2019. We found that:

  • Possibility of a deal with the EU will likely mean accepting current EU regulations governing GMOs in food for the foreseeable future, as changing food standards is politically difficult.

  • In the event of a ‘no deal’ Brexit, there may be a food crisis due to reduced import of food from the EU and increased checks on the border.

  • Cheese and other dairy products are likely to be one of the hardest hit food groups in this event.

  • Changing to a less restrictive system of GMO regulation may be a necessary part of forming trade deals with other countries.

  • A passive way of checking food for contamination (such as our device) could reduce the time at the border and thus reduce the potential price increase in the event of a no deal Brexit.

  • Our device could address the increased need for a fast and cheap detection tool for a growing local artisan cheese industry within Britain (the status of Northern Ireland in this context is unclear), favoured by a considerably relaxed future regulatory climate. In general, our research indicates that this might be a good time for increased investment into potential synthetic biology food applications in the UK.


  • Since our project aims to integrate GMOs into food, we were considering how it will be accepted in the market. To answer that, we have arranged a video conference with three officers from the Directorate-General for Health and Food Safety (DG SANTE) of the European Commission (EC).

  • We learnt that our biosensor would be considered a category 4 genetically modified microorganism (GMM) and to gain authorisation to use GMMs they must be contained. This also added to the idea of developing our Listeria detection test as an isolated cell detection system using Escherichia coli rather than an integrated test using Lactococcus lactis.

  • We would need to design future tests to prove that our biosensor would not produce false negatives to be accepted by the EFSA risk assessment.