An international research team has proposed using bacteria to bind Martian soil into concrete-like structures, offering a lower-energy and more sustainable way to build future habitats on Mars.
What The New Research Is Proposing
A new perspective paper published in Frontiers in Microbiology examines whether biomineralisation, a natural process driven by microorganisms, could be adapted for construction on Mars using local materials rather than imported building supplies. The research is led by Shiva Khoshtinat at Politecnico di Milano with collaborators from the University of Central Florida and Jiangsu University.
The researchers (the research is ongoing) are focusing on biocementation, a specific form of biomineralisation in which microbes trigger the formation of calcium carbonate minerals that can bind loose particles together. On Earth, similar processes have been explored for soil stabilisation and experimental low-carbon construction. The paper argues that a carefully engineered version of this approach could be viable on Mars, where energy, materials, and human labour will all be severely constrained.
As the researchers write, “Given the high cost and logistical complexity of transporting construction materials to Mars, the development of autonomous in situ resource utilisation technologies is imperative.”
Why Mars Construction Demands New Thinking
Building on Mars is likely to be fundamentally different from building on Earth. For example, the planet’s atmosphere is extremely thin, surface pressure is less than one percent of Earth’s, and temperatures fluctuate sharply between day and night and across seasons. Radiation exposure is also far higher due to the lack of a global magnetic field.
For future human missions, these conditions will mean habitats must be robust, well-shielded, and ideally constructed using local materials. Transporting large quantities of steel, concrete, or prefabricated components from Earth would simply be prohibitively expensive and energy intensive.
This is why space agencies increasingly focus on in situ resource utilisation, commonly referred to as ISRU, which aims to use local materials such as regolith, ice, and atmospheric gases to support life and infrastructure. The new paper positions biocementation as a potential addition to that toolkit.
Why Conventional Cement Falls Short On Mars
One of the key technical drivers behind the proposal is the chemical mismatch between Martian soil and conventional cement production. For example, Martian regolith contains many familiar oxides, including silica, alumina, iron oxides, and magnesium oxide. Calcium oxide, however, is present at much lower levels than those required to produce Portland cement, which relies heavily on calcium-based compounds.
The researchers have noted that this is likely to make producing a true Portland cement analogue on Mars very difficult without importing large amounts of calcium from Earth, which would undermine both cost efficiency and sustainability. Instead, they argue that calcium carbonate-based binding, supported by microbial activity, may be more compatible with Martian geochemistry.
Biocementation, therefore, appears to offer a way to work with what Mars naturally provides, rather than forcing local materials into Earth-based industrial processes.
How Biocementation Works
Biocementation relies on microorganisms that alter their chemical environment in ways that cause minerals to precipitate, i.e., it is a process where microorganisms form calcium carbonate that binds particles together. In this case, the target mineral is calcium carbonate, the same compound found in limestone and chalk.
When calcium carbonate forms between grains of soil or regolith, it acts as a natural binder. Over time, this process can transform loose material into a solid mass with meaningful compressive strength, without the need for high temperatures or large energy inputs.
The researchers describe this as a potentially low-energy alternative to regolith sintering, which requires heating material to extremely high temperatures to fuse it together.
As their paper explains, “Unlike thermal or microwave-based sintering of regolith reliant on solar, stored electrical, or nuclear energy, biocementation operates at low temperatures with low energy demands, making it suitable for Mars’ limited power systems.”
The Two Micro-organisms At The Heart Of The System
The proposed system centres on a co-culture of two micro-organisms, each chosen for complementary capabilities, which are:
A bacterium that produces the enzyme urease, which breaks down urea into ammonia and carbonate ions. In the presence of calcium, this leads to the formation of calcium carbonate crystals, effectively cementing surrounding particles together. This organism has been widely studied on Earth for biocementation applications.
A cyanobacterium, a photosynthetic microorganism capable of surviving in extreme environments. Certain strains have demonstrated resistance to desiccation, intense radiation, and prolonged exposure to Mars-like conditions, including experiments conducted outside the International Space Station.
In the proposed system, the cyanobacterium plays several roles. For example, through photosynthesis, it consumes carbon dioxide and releases oxygen, helping create a more hospitable micro-environment for its bacterial partner. It also produces extracellular polymeric substances, sticky biological materials that help microbes adhere to surfaces and provide nucleation sites for mineral formation.
Describing this relationship, the researchers write, “Chroococcidiopsis breathes life into its surroundings by releasing oxygen, creating a welcoming microenvironment for Sporosarcina pasteurii. In turn, Sporosarcina secretes natural polymers that nurture mineral growth and strengthen regolith, turning loose soil into solid, concrete-like material.”
From Microbes To 3D Printed Structures
The authors envision this microbial system being integrated with robotic additive manufacturing, essentially large-scale 3D printing adapted for Mars.
In practice, regolith would be mixed with microbial cultures and nutrients inside a controlled, pressurised environment. The resulting slurry could then be extruded layer by layer to form walls, arches, or domed structures designed to withstand internal pressurisation and external dust storms.
Advanced robotic systems would manage mixing, extrusion, and curing, using sensors to monitor moisture levels, pH, temperature, and ion concentrations. Multi-channel nozzles could keep components separate until the final stage of printing, reducing the risk of clogging caused by premature mineral formation.
This approach aligns with broader trends in off-Earth construction, where automation is seen as essential for safety, consistency, and scalability.
Energy Use And Sustainability Considerations
A major sustainability advantage highlighted in the paper is reduced energy demand.
For example, heating regolith to the point where it melts or sinters requires large amounts of power, which early Mars settlements are unlikely to have in abundance. Biological processes, by contrast, operate at ambient or moderately controlled temperatures.
The researchers cite comparative figures suggesting that producing calcium carbonate through biocementation requires far less energy per tonne than thermal sintering, even when compared with lower-energy microwave approaches. While they stress that these numbers are indicative rather than definitive, the contrast underlines why low-temperature chemistry is attractive in a resource-constrained environment.
This energy efficiency also resonates with current challenges on Earth, where cement production now accounts for a significant share (around 8 per cent) of global carbon dioxide emissions and alternatives are actively being explored.
Turning Waste Into Useful Inputs
The proposed system also fits into a wider vision of closed-loop resource use. For example, the urea required for the biocementation process could potentially be sourced from human waste, such as urine. Also, carbon dioxide is abundant in the Martian atmosphere and could feed photosynthesis. Oxygen released by the cyanobacterium could support life support systems, while ammonia produced during urea breakdown may eventually play a role in agriculture.
In their research paper, the authors summarise this integrated approach clearly, stating that biocementation “holds promise not only for infrastructure construction but also for integrated resource cycles, producing oxygen and ammonia as byproducts.”
Key Challenges And Questions
Despite its promise, the paper is careful to emphasise how early-stage the concept remains. Water availability and purification are major concerns, particularly due to the presence of perchlorates in Martian soil and ice, i.e., highly reactive salts that can be toxic to living organisms and interfere with biological processes.
Also, long-term microbial behaviour under reduced gravity is largely unknown, and the combined effects of radiation, temperature swings, and low pressure on co-cultured organisms have not been fully explored.
The lack of returned Martian soil samples also limits experimental validation, forcing researchers to rely on simulants that may not capture all relevant properties.
The researchers acknowledge these uncertainties directly, writing that “without integrated, long-duration testing in analog or space environments, the pathway from concept to application remains highly speculative.”
Other Groups Exploring Biological And Regolith Based Construction
The idea of using biology or low energy chemistry to support off Earth construction is not limited to this one research team. In fact, several space agencies and universities are investigating related approaches, often with a similar sustainability motivation. For example, these include:
– The European Space Agency, which has previously supported the BioRock experiment, led by researchers at the University of Edinburgh, which studied how bacteria interact with basalt under microgravity conditions aboard the International Space Station. While BioRock focused on biomining rather than construction, it demonstrated that microbial processes can still function in reduced gravity environments, a key prerequisite for any biological ISRU strategy.
– NASA has also funded multiple studies into microbially induced calcium carbonate precipitation for soil stabilisation on Earth, including work exploring whether similar processes could one day be adapted for lunar or Martian regolith. These projects have largely remained at the laboratory and modelling stage, yet they provide a growing body of data on how biocementation affects strength, porosity, and durability.
Also, alongside biological approaches, engineering-led programmes are exploring alternative low energy construction routes. For example, NASA’s collaboration with ICON and academic partners has tested large scale 3D printing using simulated Martian and lunar regolith, focusing on structural geometry, automation, and radiation shielding rather than biology. These projects highlight how additive manufacturing and ISRU are increasingly converging across different disciplines.
Together, these parallel efforts suggest that future off Earth construction is unlikely to rely on a single solution. Instead, biological systems like biocementation may sit alongside robotic printing, chemical processing, and regolith based shielding as part of a broader toolkit aimed at reducing energy use, imported materials, and environmental impact during long duration space missions.
What Does This Mean For Your Organisation?
What this research makes clear is that biology is starting to be taken seriously as a practical engineering tool for space, not just a scientific curiosity. The proposal doesn’t promise quick wins or near-term deployment, and the researchers are explicit about the technical and environmental hurdles that remain. Even so, it shows how future Mars infrastructure could be built around low energy chemistry, local materials, and closed-loop systems rather than brute-force industrial processes transplanted from Earth.
That shift matters beyond space exploration. For example, many of the same pressures apply on Earth, where construction faces rising energy costs, tighter carbon targets, and growing scrutiny of cement and concrete. Research into biocementation, low temperature mineral binding, and waste-derived inputs is already influencing experimental construction methods here. For UK businesses working in construction, materials science, robotics, or environmental engineering, this kind of work points to where longer-term innovation and funding interest may head, especially in areas linked to low carbon building materials and automated construction.
For other stakeholders, including space agencies, regulators, and sustainability researchers, the study reinforces the need for interdisciplinary thinking. Mars construction will not be solved by materials science alone, or biology alone, or robotics alone. It will most likely require systems that combine all three in ways that are reliable, scalable, and demonstrably safe.
This research does not claim to have solved that challenge, but it does set out a credible path forward, one where sustainability constraints shape engineering choices from the very start rather than being treated as an afterthought.
