This year the Stanford-Brown-RISD iGEM team worked with the Danish Technical University (DTU) overgrad team from the beginning. Both teams were inspired by the idea of mycotecture as funded by the NASA Innovative Advanced Concepts Program to our faculty advisor, Dr. Rothschild. With our expertise in applying synthetic biology to problems of space exploration and settlement, and DTUs particular expertise in filamentous fungal biotechnology, we worked together towards the goal of using synthetic biology enabled fungal mycelia as an material for space settlement. We shared protocols for growing the material and helped troubleshoot each other’s projects. Both teams agreed to frame the project around a mission to the Martian surface and with with advice from resident NASA experts, both teams worked to add suitable benefits to the material.

Modeling

Both teams possessed some expertise in modeling and decided to put it to use to create models which described different stages of the mycelium production process. Working together, the goal was to have models which could inform future scientists that wish to use mycelium from the stage of a single spore all the way to building the final structure.

The DTU team created two models, one taking us from a single spore and modeling its hyphal growth and the second modeling what properties of mycelium would be necessary in a building Brick to make the final structure. Our team worked on a model which spanned the intermediate between the two, taking a large colony of fungus and modeling its growth into a mold from which building Bricks could be made. Further details on the two teams’ models can be found below.

Our teams met several times over video chat to compare and contrast our approaches to models. Key takeaways follow:

• The DTU model begins from a single spore; SBR’s begins from a “plug” of existing mycelia of given dimensions.
• DTU’s model maps 2D, unconstrained growth; SBR’s model maps 3D, constrained growth (within a mold). Note that early iterations of the SBR model mapped 2D, unconstrained growth; this was changed to better suit our unique use-case for the model.
• Both models incorporate density but define it differently: DTU’s defines density as the concentration of individual hyphae in a given surface area, whereas SBR’s defines density as the proportion of the physical mold that is filled from the base upward.
• Both models’ parameters can be fine-tuned in accordance with lab results in order to account for the use of different fungi.
• The SBR model is based on the Eden Model for tumor growth; DTU’s is based on a few different approaches, including a branch-extension simulation that provides the bulk of their rationale.

Finally, taken together, the two teams’ models can form a cohesive use-case. DTU’s first model simulates fungal growth kinetics from a single spore, growing into 2 dimensions and forming the initial “plug” used to fill the mold--this is the SBR model. Finally, DTU’s second model gives the properties of the brick necessary to make the final structure. In essence, DTU's model depicts the beginning and the end of the process, and SBR's model depicts the middle.

The DTU Team's modeling can be viewed here Our team's modeling can be viewed here

Physical Testing

Despite our two teams being separated by almost 6000 kilometers we were able to meet up with one advisor from the DTU Team, Kyle Rothschild-Mancinelli (in the gray jacket) who stopped by the Ames Research Center to look at our progress and exchange mycelium so that we could perform testing in our respective labs. Thanks to this visit we were able to test our glue on an independently created mycelium, further validating our results. In turn our advisor also was able to visit the DTU team in Denmark and advise on any questions they had about creating a mission to outer space.

To see the results of our physical testing on DTU’s bricks as well as our own please see our physical testing page, linked here