Human Practices

Human Practices play an important role in our project. The Space Yeast project can significantly impact future generations. To maximize its relevance, we organized our Human Practices considering different stakeholder views to cover all levels, from researchers working with melanin and cell factories to astronauts and radiation experts. To get from ideas to applications we progressed in the design of our project with continuous input from professionals. While advice for engineering was crucial to bring our project idea to life, further implementation that had to go beyond basic scientific research was an important element for us. As we learned more about space missions from experts, we decided to share this knowledge with other people through a public survey. All these joint actions guided the project development by identifying possible issues along the way and integrating advice from different stakeholders.

Human Practices & Integrated Human Practices
ASTROSHIELD
Sao Carlos-Brazil team members, who did a project related to melanin producing yeast in 2019, reached out to us and proposed an online meeting to discuss potential benefits and risks associated with our project. During the meeting we discussed the challenges that their team faced three years ago, and they shared some useful suggestions with us. For example, we implemented the yeast display strategy that they used, but in a modified way by fusing tyrosinase to the yeast display protein Aga2. We also learned about a melanin-binding peptide and incorporated a similar peptide in our project design. Knowing their attempts and issues, we designed three different approaches to test experimentally. Members of the Brazil team pointed out that based on their experience, melanin is extremely hard to deal with because it is insoluble and toxic to the cell. The latter was one of our main concerns and driving force to go for multiple strategies for melanin production. One of the pieces of advice that we were given was to test our results as soon as possible to make sure that the substance synthesized is indeed melanin.
When coming to professional researchers, we turned to Ekaterina Dadachova, as she has done extensive research on melanin as a radioprotector. We had an extensive discussion with her about her work on melanizing fungi and their properties. There are multiple possible pathways to synthesize melanin and there are multiple types of melanin. We had possible pathway candidates based on our literature research, however, due to lack of experience with this compound, we asked for a consultation from Prof. Dadachova. We were advised to proceed with the L-DOPA pathway since it will be easier to implement in S. cerevisiae. Another important question was to figure out which type of melanin has the best radioprotective properties. Since Prof. Dadachova has worked on this topic, she was able to provide us with pointers that pheomelanin can be more useful in our case and it is possible to synthesize it from a precursor containing sulfur. This knowledge can be used by us in the later stages of the project to further improve our yeast strains. From this conversation, we learned that melanin has a strong paramagnetic signature and very characteristic signal in electron paramagnetic resonance (EPR). This can be used as one of the methods to confirm that the produced compound is indeed melanin. Her knowledge provided valuable assistance in understanding what direction we should move, as well as she gave some specific advice on methodology.
Ekaterina Dadachova
Li Chen Cheah
Ms. Li Chen Cheah has done research into how to use nanocompartments to improve production in yeast metabolic pathways. We turned to her for advice, since one of our strategies is to synthesize melanin inside viral-like nanocompartments. She shared that the nanocompartment technology is still new and a lot depends on species and that it is hard to predict how it will work in our case. The compartment assembly is greatly affected by the choice of cargo protein, and there is currently no straightforward way of predicting which proteins will be encapsulated well. Ms. Li Chen Cheah also suggests trying a few strategies for our project, because there are many uncertainties and some of them might be risky. Because of the associated risks, but also the benefits of using nanocompartments, we kept the compartmentalized melanin synthesis as one of our three experimental approaches.
Felice Mastroleo is a scientist at SCK CEN (Belgian Nuclear Research Centre) working on the border of microbiology and space research. He is participating in the Micro-Ecological Life Support System Alternative (MELiSSA) project whose main goal is life support systems in space. He raised two main points during our discussion. First, he advised us to find a specific detailed application, so that we could proceed with a more targeted approach. Another aspect he raised was that in space there are multiple harsh conditions, and sometimes it might be hard to separate the effects from them, i.e. radiation and microgravity. Felice mentioned that the idea of using bioreactors in space is not very common and it is groundbreaking research that can help solve issues with life support in space. He mentioned as well that there is a possibility of doing a collaboration with us as we do not have specific hardware for radiation testing. These further steps would also lead to a publication. To proceed further with proper testing methods, he referred to us his colleague who works specifically with space dosimetry.
Felice Mastroleo
Sergey Ryazansky
As our project can potentially be used on the International Space Station (ISS), we wanted to reach out to an astronaut. We found a perfect match for our project that combines biology and space - the world's first scientist who became a spacecraft commander - Sergey Ryazansky. He kindly shared information about his experience in space and gave more practical information which we later used in our public survey to bring awareness for regenerative life support demand in space. Sergey told us about cargo ships, water reuse and about future technologies that can be used on ISS. He shared that during his missions he collected microorganism samples from the inside and outside of ISS, and brought them back for further research. One of the issues we discussed was radiation protection. Currently from his knowledge, the ISS does not provide full protection. There are dosimeters that monitor the level of acquired radiation. To explain that this problem is still under research, Mr. Ryazansky told us about the ongoing experiments on the ISS that study cosmic radiation penetration level in different tissues. Sergey also mentioned that it is difficult to differentiate between microgravity and radiation effects on microorganisms. Currently, NASA sent yeast to space in order to examine how microgravity and space radiation affect them. The samples will be continuously exposed to high-energy cosmic rays for several months. After this study, we should gain a better understanding of how severe conditions affect microorganisms and later we can use this knowledge to bring our project closer to real applications. Overall, Sergey Ryazansky gave us a better understanding of current space missions situations, reaffirming our initial hypothesis that there is no radiation protection, which confirms that our project is indeed needed.
After multiple discussions with other researchers, we came to Olivier Van Hoey - a researcher in Radiation Protection Dosimetry and Calibration Expert Group at Belgian Nuclear Research Centre whose contact we got from Felice Mastroleo. We discussed in depth about different types of radiation and how to measure it. One of the discussed topics was that in space it is very hard to be protected from radiation. For example, on Mars one could dig bioreactors into soil to protect them from radiation. From the discussion with Olivier, we discovered that the possible usage of radioprotection is more critical during yeast transportation during long space voyages. Without the melanin shielding, alternative protection is necessary, for example by putting the yeast in a lead container, but that would be extremely heavy and expensive. Hence, by applying our method we can greatly reduce the costs of transportation.
Olivier Van Hoey
Public Survey To assess the interest of the public in our topic, as well as test people’s assumptions about space, our team carried out a public survey. First part contained more educational questions which also tested the variance of opinions. Questions about resupply missions had very varying answers, which shows that the public is not well informed about this issue. Without providing the answer choices it would be even harder to guess how much does NASA pay per kilogram of a shipment. The second part of the survey revealed that more than half of the respondents believe that Mars or other planets can be colonized in the next 5-100 years, which is not that far in time. Hence, our research is a relevant step to prepare for these steps. Part three of the questionnaire asked about people’s opinion about Genetically Modified Organisms. It was pleasant to see that the majority of participants were not totally against GMOs, meaning the society’s opinion is slightly moving towards GMO-tolerance. In the last part of the survey we asked what people think about our project. People had a positive attitude towards melanized yeast and the majority believed that it can be a successful project.