In the goldfields of Western Australia, researchers have discovered a variety of fungus called Fusarium oxysporum which literally means ‘Midas touch’. This organism is pink in color and is able to interact with mineral deposits underground, break them down into a liquid state and eventually grow solid gold crystals on thread-like hyphae.The presence of gold on the hyphae of this fungus allows for increased growth rate and size compared to their non-gold-infused cell cultures. Researchers now plan to further investigate using this organic alchemy to mine precious metals on the Moon and Mars. By using fungal bio-mining technology, future missions will be able to use a terrestrial biological wonder to provide the basis for extraterrestrial resource recovery infrastructure.
A fungus in Western Australia that eats gold
Researchers at CSIRO (Commonwealth Scientific and Industrial Research Organisation) discovered that Fusarium oxysporum is known to absorb gold from its surroundings through the process of dissolution and precipitate this gold in the form of nanoparticles on hyphae (branched filaments). This process is highly reactive in nature and involves the production of superoxide by the fungus which is used to oxidize the gold, thus allowing the coating of gold on the fungus.
Why does fungus like to sleep?
The analysis, published in the journal Nature Communications, shows that fungi that are coated with gold exhibit higher growth rates than fungi that are not coated with gold, compared to fungi that do not interact with gold. This suggests that the presence of gold may assist as a catalyst for biochemical reactions or aid in the uptake of other nutrients, thus giving the fungus a competitive advantage in the extremely mineral-rich environment of the Australian Outback.
How do microorganisms replace heavy machinery?
The exploration of microorganisms processing minerals, commonly known as bio-mining, is a hot topic in studies by agencies such as NASA and ESA regarding potential implementation in space. Invisible to the naked eye, due to the prohibitive cost of carrying large amounts of heavy equipment to the Moon or Mars, workers like Fusarium oxysporum could potentially be employed to extract gold and other metals from regolith, or soil on other planets. The biological aspect of in-situ resource utilization (ISRU) will support human presence in space in a more sustainable way in the long term.
How biological signatures could eliminate the need for expensive exploratory drilling
Apart from space applications, this discovery also has many immediate applications on Earth. CSIRO scientists say the presence of gold-coated fungi growing on the surface is an indicator to mining companies that deep underground deposits of gold may exist in large concentrations, and so using biological indicators earlier could eliminate the need for expensive drilling for exploratory purposes.