Overview

With the continuous deterioration of the Earth's environment, the day will come when mankind has to migrate to another planet. Mars, as the closest Earth-like planet, might be the first destination for interstellar migration. This year, our team created a lichen-like biofilm with cyanobacteria and E. coli to modify the environment of the Martian surface, preparing a "second home" for mankind. The biofilm could survive the harsh environment of Mars, with high radiation, severe drought, huge temperature differences, and extreme sandstorms, and transform bare rocks into fertile soil. Using our products adeptly and correctly, the ultimate goal of terraforming Mars might be accelerated. Besides, our product is of environmental and commercial value, with potential applications in multiple fields on Earth.

How to use

Considering that our transformation target is the desolate Martian rocks, we intends to use cyanobacteria and E. coli as the chassis to construct a living biofilm and apply them to the rock surface.

1. Spray and Form a Living Biofilm

   Enabled with the Biofilm Formation System (more details in Description), the cyanobacteria and engineering E. coli form a living biofilm. Sprayed on the Martian surface, the biofilm will quickly spread and cover the bare rocks with the bacteria proliferating. Cyanobacteria will take full advantage of atmospheric CO₂ to produce enough energy and organic substances by photosynthesis. Thus, without any extra support, the biofilm could consistently grow on Mars.

2. Provide Water Source

   For the severe drought on the Martian surface, a water source is necessary for the successful settlement of the biofilm. To provide a water source, we could collect the abundant ice on Mars, melt it into water by heaters, and spray the water onto our biofilm.

3. Biological Weathering Agent Simulating Lichen

   Approximately 24 hours after providing the water source, the biological weathering agents begin to take effect. Genetically modified E. coli is responsible for mimicking lichen function by secreting oxalic acid and extracellular polysaccharide (EPS). Oxalic acid forms cation-organic complexes with mineral cations, inducing a transfer of electron density towards the mineral framework, thereby expediting the progress of physical weathering. The bare rock on the Martian surface will gradually break down into small pieces of gravel and then powder. With EPS, the powder will condense and eventually form fertile soil.

   
   

   The progress of biological weathering promoted by our biofilm

4. Survival System for Long-term Growth

   A survival system (more details in Description) was introduced into our biofilm to enable it with resistance to the harsh environment of Mars.

Safety Concerns

For the well-being of all mankind, we have collect insights on the safety concerns of our product from the perspective of environmental ethics and bioethics (more details in Human Practice). Aware of our responsibility to manage the risk, we have made multiple attempts to ensure the safety in the future application of our product (more details in Safety).

On Earth

Our biofilms can not only modify rocks in outer space and form soil on Earth-like planets. The various components of biofilms have their own unique roles, and there are potential applications on Earth that can already be adopted.

Multiple potential applications of our product

1. Environment: Addressing Soil Problems

   The production of oxalic acid by engineered bacteria has potential applications in the transformation of soil. Salinization is known as the "stubborn disease" of the land, and the soil salt content is so high that crops are low-yielding or cannot grow. Oxalic acid could be used to solve soil salinization, and the production of oxalic acid by engineered bacteria (opens new window) could be massive and gradually improve saline soil.

2. Agriculture: Improve Crop Production

   Engineered bacteria producing EPS (e.g. BBa_K4765121 (opens new window)) is effective in order to improve soil fertility. Extracellular polysaccharide is the binder to form soil aggregate structure and keep the aggregate stable^[1][2]. The use of microbial EPS to improve the soil can make the soil more loosened and permeable and reduce soil crusting, which will be beneficial to crop production.

   Antifreeze protein (BBa_K4765111 (opens new window)) produced by engineered bacteria can be used to improve crop viability. Low temperatures may cause crops to suffer from frost and thus reduce yields. Biological anti-freeze provides new ideas in the field of crop improvement^[3].

   Anti-desiccation protein (BBa_K4765112 (opens new window)), when used in crops, can enhance water retention and greatly improve recovery from drought and water scarcity. It could improve crop production in arid areas.

3. Cosmetic: Sunscreen Products

   MAAs have potential applications (opens new window) in the field of biological sunscreen. Batch production of traditional chemical sunscreens causes pollution of chemical waste. UV-resistant substances MAAs extracted from biological sources could open the way for the production of environmentally conscious UV-absorbing coatings^[4].

4. Synthetic Biology: Regulated Polycistronic Expression for Metabolic Enginnering

Improving chassis metabolism for health or commercial usage is one application of synthetic biology. Fudan iGEM 2022 (opens new window) archived β-carotene production in single bacteria using four BioBricks (opens new window) connected by ribozyme. This year, we have developed a software tool, to facilitate polycistronic expression using ribozyme, in the real-world.

References

1. Ates O (2015 Dec). Systems Biology of Microbial Exopolysaccharides Production. Front Bioeng Biotechnol, 18(3), 200. https://doi.org/10.3389/fbioe.2015.00200 ↩︎

2. Mager D, Thomas AD (2011 Feb). Extracellular polysaccharides from cyanobacterial soil crusts: A review of their role in dryland soil processes. J Arid Environments, 75(2), 91-97. https://doi.org/10.1016/j.jaridenv.2010.10.001 ↩︎

3. Muñoz PA, Márquez SL, González-Nilo FD, Márquez-Miranda V, Blamey JM (2017 Aug). Structure and application of antifreeze proteins from Antarctic bacteria. Microb Cell Fact, 16(1), 138. https://10.1186/s12934-017-0737-2 ↩︎

4. Singh A, Čížková M, Bišová K, Vítová M (2021 Apr). Exploring Mycosporine-Like Amino Acids (MAAs) as Safe and Natural Protective Agents against UV-Induced Skin Damage. Antioxidants (Basel), 10(5), 683. https://doi.org/10.3390/antiox10050683 ↩︎