What is our chassis organism?
We used standard commercially available chassis organisms: E. coli strains T7 Express, T7 lysY/Iq, NEB 5-alpha, VH33.
Did we experiment with any other organisms?
We will experiment with the alga Chlamydomonas reinhardtii, utilising a natural endogenous pathway (requiring sulfur deprivation and absence of light) to produce both oxygen and hydrogen gas.
How does our project work?
Our entire project is to do proof-of-concept work for a biologically produced balloon that can explore planetary atmospheres. This involves creating several membrane prototypes made out of latex, collagen, elastin, and p-aramid fibers. E. coli transfected with appropriate DNA will be made to produce these materials endogenously, then lysed so that the protein/polymers can be extracted and assembled into sheetlike structures. Additionally, E. coli will be made to produce melanin that can be linked to our various membrane types using a binding domain by taking advantage of E. coli's tyrosinase pathway. An additional project is using the natural gas production cycle of Chlamydomonas reinhardtii to produce hydrogen and oxygen gas for flight in various atmospheres. Finally, for sensing we are using DNA-based aptamers and chromoproteins. The aptamers can sense for various target molecules in space, allowing us to probe the surrounding terrain. The chromoproteins undergo a conformational change that manifests as a physical change in color, allowing them to be used as a type of thermometer when many types of chromoproteins are used at once. They are produced in E. coli, purified, concentrated, and then bound to cellulose sheets to create a temperature-sensitive colour gradient for sensing nearby temperatures during flight.
How did we limit risk-taking actions during our project?
E. coli is a relatively safe organism to work with, but we are still engineering genes into our E. coli that confer a number of dangerous properties, such as antibiotic resistance and the ability to create and secrete proteins that are not innate to E. coli. We reduce the risk of allowing our E. coli to grow and reproduce outside of our experiments by wearing gloves, sterilising our biowaste before throwing it away, and spraying down surfaces with ethanol.
How do we envision our project being used in the real world?
We envision our project as a biologically-created weather balloon for exploration on Earth, Venus, Mars, Titan, or other planetary bodies.
What risks might our project pose in the "real world"? What future work are we doing to reduce these risks?"
Our latex production project could result in the collapse of the southeast asian latex farming industry. Our human practices project focuses around the work that might need to be done in the future for responsibly introducing this production method into the greater community. Other risks that our project may pose is that the balloon may introduce (biodegradable but still foreign) waste onto non-Earth planets, and we can work in the future to increase the degradability of our project as well as develop safe recovery mechanisms for our balloon in space.
Find our final safety form submission here.
You can download our part safety spreadsheet here.
Team:Stanford-Brown/Safety
