Team:Manchester/Human Practices

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Human Practices

Cheesemaker from Rokiškio sūris
Short summary
  • Our project is designed to make cheese products safer. If applied, this idea would influence current cheesemakers. However, if we would like cheese makers to consider our innovation, first we need to examine their suggestions because they are experts in making cheese and so can advise us on our project design.
  • We have 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.
  • Also, Vadimas mentioned that GMOs in cheese are not acceptable and that 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.
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Rokiškio sūris
The Whole story

To get a real-world cheese maker's perspective on the industrial constraints affecting our project we spoke to Vadimas Kličius, who is the director of new product development in “Rokiškio sūris” - a major cheese manufacturer in Lithuania. Mr. Kličius introduced us to the safety measures employed in the company to keep products safe. To ensure safety, samples are taken during different stages of the cheese making process. Since tests for pathogenic bacteria (e.g. Listeria or Salmonella) cannot be run in the cheese making factory (because tests require growing potentially pathogenic cultures, which are forbidden for safety reasons), all samples are sent to external microbiology labs for analysis. It takes around 1 to 3 weeks to get the results back. Most interesting for the assessment of the economic feasibility of our alternative testing device was information on the price of this off-site testing of cheese samples. Current tests involve the following costs:

Example prices at National food and veterinary risk assessment institute of Lithuania:

  • Detection of L. monocytogenes in (26 g - 125 g of the sample) - 27 Eur ≈ £ 24 ≈ $31.8
  • Detection of L. monocytogenes by BAX Q7 method - 21 Eur ≈ £ 19 ≈ $24.7
  • Detection of the number of L. monocytogenes in food products - 12-16 Eur ≈ £ 11-14.5 ≈ $14.1-18.8
  • Detection of the number of L. monocytogenes in food products - 12-16 Eur ≈ £ 11-14.5 ≈ $14.1-18.8
  • Detection of L. monocytogenes by PCR method - 30 Eur ≈ £ 27 ≈ $35.3

We learned from Mr. Kličius that L. lactis, the bacterial species we are targeting in our iGEM project, is not necessarily used to make soft cheeses (e.g. mozzarella). The species is instead mostly used for making semi-hard cheeses, which are currently not the target of our detector device. However, according to Mr. Klicius, modified L.lactis for Listeria detection could theoretically also be integrated into the soft-cheese starter cultures without negative effects on product quality.

On the other hand, we learned that the choice of a mesophilic bacterium L.lactis might not be optimal for industrial applications of our system. Firstly, some soft cheeses (e.g. mozzarella) have a formation step where the pre-cheese mass is heated up to 59-62°C and cheese is formed. Also, the process of making the majority of hard cheeses includes a stage where cheese granules are heated up to 38-58°C to dry them and control the fermentation process. A sensor system based on L.lactis bacteria would probably lose its function or even would not survive in such temperatures. Secondly, to make mature cheeses, they are kept at 9-12°C to keep the fermentation process slow. If L.lactis bacteria are added, the maturation rate would increase because such temperature is optimal for our mesophilic bacteria to grow. As a result, cheese quality and flavour might change.

When asked about the potential of our Man-Cheester project, Mr. Klicius responded that the idea is promising but currently no one would buy a cheese-containing GMOs. He even mentioned that big companies which are buying products from “Rokiškio sūris” ask for tests which prove that products do not contain GMOs. This confirmed our earlier insights talking to artisan cheese makers, who expressed similar concerns. Thus, although interaction with potential customers indicated that they might be much more open to GMO for cheese safety testing, the commercial viability of our device would depend on a change in risk perception among cheese producers and sellers, as well as changes in the regulation of GMO in food. As a result, we had intense discussions with the European Commission regulating relevant GMO policies, but we also explored possible modifications to our device that would ensure that no live GMOs are contained in the final product - considering that GMO-derived ingredients, such as vegetarian rennet, are widely accepted in commercial cheese products.

Cheesemaker from Burt's cheese
Short summary
  • We have visited a local cheese maker Claire Burt to get to know about the cheese making process and 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 the major sources of Listeria contamination are various surfaces or water used in the process. That suggested us that having a cell-free or an isolated-cell test would be more convenient than a biosensor integrated into the product.
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Visit to Burt’s Cheese
The Whole story

On the 5th of June, we were kindly invited to ‘Burt’s Cheese’ in Cheshire. The owner, Claire Burt, was generous enough to give us a full demonstration of the cheese making process where we learned the importance of pH and temperature control in cheese manufacture. With this data, we were able to amend our current cheese making protocol to fit better for a soft, white mould cheese. Our original cheese making protocol did not use any other live culture besides our E. coli but Claire advised us to include other cultures. These other cultures are used to produce flavors and/or CO2 in cheese with eyes. This meant we now needed to control for pH and temperature more strictly. For example, culture must be added at 17°C and increased slowly to 30℃ rather than simply heating to 32°C. We were also informed that it was important to check the pH of the milk is as close to 6.74 as possible for an optimal batch.

Claire Burt also gave us a good insight into the hygiene practices she must adhere to ensure her cheese is safe. For example, Claire uses an ozone producing machine in order to control phage contamination. There is also a strict hygiene checkpoint at which hairnets, lab coats and shoes are changed to minimise the introduction of outside contaminants. We discovered where and how any foodborne pathogens can enter the process. Of particular concern to Mrs. Burt was the hygiene quality of the large metal vat that the farm used to store pasteurised milk. She also stated that Listeria, when present, is often on surfaces and within the water. In addition to this, we learnt that small-scale cheese producers often only send swab samples to labs every 3 months due to the high costs associated with testing. An outbreak of Listeria can be extremely damaging within this space of time. For example, a recent L. monocytogenes outbreak in South Africa lasted 15 months, infecting over 1000 and killing over 200 people. (Blomfield, 2018)

From our visit we decided that, seeing as Listeria monocytogenes contamination was possible at the first stage of processing (the storage vat) we should integrate our biosensor into the cheese itself. Rather than developing the sensor in an external Escherichia coli bacterium, we made the milestone choice to integrate the E. coli into the cheese starter culture. In doing this, the bacterium will always be detecting L. monocytogenes, drastically reducing the time the pathogen spends in the food. Claire Burt also prompted us to research the pathogen detection market to see if we could produce our biosensor as a cheaper alternative to lab grade testing for smaller producers.

British Science Week 2018
  • We were volunteering in the British Science Week 2018 and presented at the stall "Making medicines in cells".
  • We have introduced school students to the concept of DNA replication and translation.
Public Engagement session in Manchester Museum
  • We hosted a small stand in The Manchester Museum as part of ‘University of Manchester Community Fest’.
  • We introduced members of a 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.
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Public Engagement event in Manchester Museum
The Whole story

We hosted a small stand in ‘The Manchester Museum’ as part of ‘University of Manchester Community Fest’. As this was an event aimed at families, we had a colouring activity for children. We asked the children to colour what they think ‘good’ and ‘bad’ bacteria would look like. While the children were engaged with this activity we asked parents questions about their views on GMO containing cheese. These questions were:

  • Do you like cheese?
  • Is there anything specific about it you enjoy?
  • Do you have any concerns about cheeses? (Particularly to do with health, disease and contamination)
  • Do you take any steps to minimise your concerns about cheeses?
  • What are your feelings regarding genetic modification?
  • What would convince you (or not) to eat GM food?
  • How would you feel about using genetic modification technology to make cheese safer?

These questions yielded a broad range of responses that are summarised below:

These questions yielded a broad range of responses that are summarised below:

Do you like cheese? Is there anything specific about it you particularly enjoy?

43 people responded to this question, with 35 stating that they enjoy cheese products regularly because they like the taste. 4 people stated that they do not like cheese, again due to its taste. 2 respondents stated their indifference to cheese. There was also one lactose intolerant individual and one vegan.

Do you have any concerns about cheese? (Particularly to do with health disease and contamination)

37 people responded to this question. 22 stated that they had no concerns about eating cheese. 7 were only concerned if they were pregnant. 3 respondents expressed dietary concerns, with 2 further expressing concerns specifically to do with cholesterol levels. 1 respondent each voiced concerns about handmade cheeses only, Listeria contamination and concern only for children.

Do you take steps to minimise your concerns about cheese?

Of the 11 people that responded to this question, 3 took no actions. 3 attempt to limit the quantity they eat. 2 keep it refrigerated. 2 did not eat soft cheeses when pregnant. 1 did not buy handmade cheeses.

What are your feelings regarding genetic modification?

We gained 27 responses to this question which are summarised below:

I try to Avoid GM Products x3
I agree with using GM for health and safety purposes x3
I do not know enough to make an informed choice x3
I do not care if food is GM or not x2
I do not agree with using GM crops for profit but using them for health and safety measures is useful
I am interested in how the laws differ around the world
They seem a good solution to many problems
I disagree with using any GMOs
I do not know anything about GMOs
Is it safe to ‘play’ with bacteria
I am scared of GM
I know that plants are modified to give a better yield
I would not eat GM food
I prefer natural products
I do not mind trying GM products but I would not give them to my child
I feel uncomfortable but would change my mind if they were cheaper

These responses informed us that much of the public are pro-GM if the technology is being used to benefit health, but are less supportive it is simply being used to reduce costs of production. There was less strong opposition than we predicted.

What would convince you to (or not) eat our GM food?

Lower Price of a product x7
If they are better educated on how the technology works x5
The use of a well known ‘good’ bacteria rather than E. coli x4
If the taste remains the same x3
Nothing could convince me x2
A full explanation of how the GMO interacts with the body
If pregnant, will the GMO interact with the fetus?
I would only eat the product if I was pregnant
I would eat the cheese if the GM organisms could be removed before consumption
I would eat the cheese if the system could be put in goats cheese rather than other soft cheese
If there are more people eating such products and they were more common

A significant number of people were supportive of our product if it were not sold at a higher price. Another common trend was a requirement of better education on GM technology to be confident in consuming our product. Possibly the most impactful comment was the trend that people are more happy to consume a GM bacteria that is commensal and well known as it removes much of the uncertainty. E. coli is commonly associated with disease in the public and media so a switch to a ‘good’ bacteria would be preferred. From these data we decided to integrate our system into the already present Lactococcus lactis rather than E. coli in order avoid the public fear of E. coli.

How would you feel about using genetic modification technology to make cheese safer? (Sticker chart for children and adults) (0=Would not eat such a cheese. 10=Would eat such a cheese as normal)