Engineering Microbes for Mars Survival

A field known as synthetic biology has become one of the most highly anticipated in science. Its outputs range from golden rice , which is genetically engineered to provide vitamin A, to advances stemming from the Human Genome Project , which successfully mapped the entire human genetic code. Prominent voices in biotechnology have heralded it as the next wave of the future of innovation.

Synthetic biology is the use of genetic engineering and other advances in biotechnology to generate new organisms or manipulate existing ones to produce the effects you desire. It is what the British biologist Jamie A. Davies calls "the creation of new living systems by design".

What is perhaps less obvious is that it may even be useful in space exploration . We might eventually use microbes to detoxify Mars - helping humans to one day live on the red planet.

Synthetic biology has transformed many lines of technological breakthrough in biology already. Thanks to technologies such as the Nobel-winning genomic "scissors" Crispr Cas9 , gene editing is now cheap, fast and accurate, as is gene sequencing.

All this means genomics can be done in the field and even in space thanks to new technology - such as the MinION by Oxford Nanopore Technologies, which allowed Nasa astronaut Kate Rubins to sequence the genomes of microorganisms on the International Space Station with a handheld device.

Structural biology has also been revolutionised by breakthroughs in cryo-electron microscopy (enabling us to view large molecules in a solution), and more recently by the Nobel prize-winning protein-folding program "AlphaFold" by Google's DeepMind.

We can now know the structure and sequence of organisms at speed and with tremendous accuracy - and at low cost. Ultimately, this also presents an opportunity to make accurate changes to sequences and structures.

This has important implications for space exploration , according to the Mars Society , Nasa and the Royal Society . Specifically, advances in synthetic biology are opening up new avenues for exploring and colonising Mars.

So, how can we engineer microorganisms to make Mars habitable? Here are a few possibilities.

Eating radiation

Microbes could help us with the damaging radiation on Mars. We know there are bacteria and other single-celled organisms known as archaea living in some of the most hostile places on Earth. For example, Thermus Aquaticus thrives in extremely high temperatures, and psychrophiles live in extreme cold.

The tardigrade genome , for example, is a rich source of information, explaining how these microorganisms can survive in the vacuum of space. Extremophiles that can digest radiation and toxicities are already used to clean up everything from oil spills to the fallout of radioactive sites.

This means we could engineer microbes that are resistant to freezing temperatures and high levels of radiation. Such synthetic microorganisms could then be put to use on Mars in a variety ways to help shield us and our habitats from these extremes - or to develop crops with resistance.

For example, it is now well known that the Martian soil is full of perchlorates , which are toxic to humans. Nasa has several ideas of how this can be dealt with, including synthetic biology.

Fixing atmospheric gases

Long ago on ancient Earth, cyanobacteria flourished . They filled an ecological niche which transformed Earth's atmosphere by enriching it with oxygen. We owe our existence in large part to this fertile bloom.

Could they do the same for us on Mars? The atmosphere on the red planet is extremely thin and primarily made of carbon dioxide. The cyanobacteria would need a lot of help, which we could provide with synthetic biology. Theoretically, microorganisms could be engineered to survive the Martian environment and in turn pump out oxygen and nitrogen.

Warming the surface

Visions of terraforming the red planet (altering it to make it habitable for humans) often involve putting space mirrors in orbit to heat up Mars and melt its ice. This would cause a runaway greenhouse effect that would transform the planet into a more Earth-like state.

But synthetic biology could (theoretically) skip this stage, which has been proposed to take at least 200 years at the very best estimate. Some five years ago, scientists proposed planetary engineering using synthetic biology to engineer microbes for ecological transformation.

Given that microbes helped make Earth habitable, we could use synthetic biology to engineer microbes to speed up a similar process for Mars. Finding organisms that reduce greenhouse gases, remove toxicity and exhale helpful substances could help remove higher levels of greenhouse gases on Earth, too.

Seeding new life on Mars

We are not yet sure there is no life on Mars. The question of how ethical it is to engineer new life and then spread it to other bodies in the Solar System for our own ends is deep and complex. But these conversations need to happen.

However, it certainly seems that synthetic biology may be our best technological bet to becoming an interplanetary species - and a lot of space and biotech agencies are taking it very seriously .

According to recent research from Macquarie University in Sydney, Australia: "From a holistic point of view, the ultimate synthetic biology approach to make the most of plant-based food on Mars would be to develop multi-biofortified crops with improved nutritional properties and enhanced quality traits (e.g., extended shelf life and reduced allergenicity)."

Among emerging technologies, it may be that using synthetic biology improves our future more than any other factor - on Earth and beyond.

Samuel McKee does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.