Safety

here our food comes from has been an increasingly relevant discussion, with emphasis on simple and low impact production changes that still result in healthy food. A topic for discussion regarding food of the future is the use of GMOs, Genetically Modified Organisms, within our food chains. The greatest concern for GMO is that we cannot rely on a long history of use, but rather trust that the work in the lab has resulted in a reliable end product.

There is a legal framework established by the European Union to ensure safe conditions for the development of GMOs. This legal framework includes a safety assessment to protect animal and human health and the environment, harmonised procedures for risk assessments and authorizations of GMOs, clear labelling of GMOs on the market, and traceability of GMOs on the market [1]. Since SoDoVi contains genetically modified yeast and lactic acid bacteria, it would be necessary to assess the potential effects of the gene modifications on the organisms. A risk assessment is necessary to evaluate the potential risks of using genetically modified organisms in a sourdough, including the impact on human health, the environment and the safety of the food product. We chose to do this project since SoDoVi would benefit human health and the environment by decreasing vitamin deficiency, contribute to a more nutritious diet and have less environmental impact than other sources of vitamins due to the reduced carbon footprint of plant based foods compared to meat. It is however important to keep in mind that the safety of the food product must be ensured in order to offer this product to consumers, and such an assessment is not included in the scope of this project.

The opinions related to GMO in Europe have been diverse and influenced by a variety of factors. What is argued by opponents of GMO is that genetic manipulation could give unpredicted, irreversible consequences. Those could affect not only natural ecosystems but also humans through the food we consume [5]. However, performing risk assessments on the GM foods currently present on the market has not presented any risks for human health [7]. Another argument against GMO is that genetic manipulation is “unnatural” and that this is a world-changing technology [5] [6]. The discussion whether something is natural or unnatural is difficult on its own. For example, going from hunting and gathering to agriculture could be seen as “unnatural” and also one of the biggest changes in the history of humanity [6]. However, if genetic manipulation would be regarded as unnatural, we would not be able to proceed with a big part of biotechnology research stopping the technological advancement and all the benefits that this could bring [6]. It must be remembered that all technology brings some changes into the world and it is difficult to predict all the consequences. However, regarding the benefits that genetic manipulation has already introduced and can continue doing so, it should outweigh the potential harm it could cause.

Local regulations and guidelines regarding lab safety and personal safety have been followed during the duration of the project. Risk assessments and safety declarations have been written to ensure both the lab and iGEM that the risks associated with our project have been considered. Appropriate safety equipment has been used in the lab such as gloves, lab coat and glasses to ensure the safety of the team members. Sterile techniques have been used to minimize contamination and correct waste management has been ensured. The lab engineers introduced the safety procedures in the lab and they, together with the team’s supervisor, have been helpful in answering all our questions related to safety.

A typical sourdough starter consists of several different bacteria and yeast strains, which ones are usually a complete mystery since it depends on the temperature and flour used to produce the starter. SoDoVi includes genetically engineering yeast and lactic acid bacteria to enrich sourdough with vitamins A and B12. Both these organisms are common both in traditional sourdough and in lab environments.

Saccharomyces cerevisiae, also called baker’s yeast, has been a chassis for genetic engineering for decades and knowledge of the procedure to grow and modify it safely is easy to attain. In addition to baker’s yeast, gene fragments from the yeast X. dendrorhous have been used. Since protocols to safely cultivate S. cerevisiae exist and the genes from X. dendrorhous to produce vitamin A have been successfully introduced into baker’s yeast before [2], this was the approach chosen to produce vitamin A in our project.

Several strains of lactic acid bacteria have been handled in this project and they all have safety level 1. None of these strains produce vitamin B12 naturally, but the genes used to introduce a vitamin B12 pathway is naturally found in other strains of lactobacillus. By using genes encoding B12 from other lactobacillus, we expected the gene modification to be easier for the used lactobacillus strains to accept than if B12 genes from another type of organism would be used.

What was early discussed in the project is antibiotic usage during the procedure of cloning. It is common knowledge that using antibiotics in food production is not preferable. However, we concluded that the project of producing vitamin enriched sourdough is in its early stage. The aim of the project is to combine Lactobacillus producing B12 with B12 dependent yeast producing vitamin A, creating a biosensor that would indicate the vitamin B12 production in the culture making the sourdough slightly orange. Whether this would be a safe product in relation to antibiotics would be a question for later studies.

An additional question remains about the concentrations of vitamins in the sourdough. Vitamin A is a fat soluble vitamin, which, unlike vitamin B12, which is water soluble, can accumulate in the body and become toxic [3]. If this project would succeed with the two vitamins, this is a discussion that would be very relevant. The first thing would be to check the concentrations of the vitamins in the sourdough. However, would this project actually turn into a product, perhaps a yeast dependent on another vitamin would be used instead of a vitamin B12 dependent yeast that produces vitamin A. For now, the project is in a very early stage with the aim to study if such a biosensor is feasible.

For the biosensor to work, we have introduced some mutations. It is common knowledge that organisms mutate and in this way the introduced mutations could be lost. The question is: how long could we expect the starter to contain the modifications we have introduced. Those rates of the mutations of the introduced yeast and lactic acid bacteria cannot be known but this is something that would be investigated in the later state of the project. One solution that has been discussed during the project was to make the organisms in the sourdough dependent on each other by using auxotrophic markers. This means that the organism is unable to synthesize all the essential metabolites on its own and is dependent on other organisms to provide them [4]. If all the organisms would be dependent on each other, the sourdough could potentially remain stable for some time.