Bacterial biorepair method enhances lunar structural bricks
Simon Mansfield
Sydney, Australia (SPX) April 2, 2025
Researchers at the Indian Institute of Science (IISC) have designed an innovative approach to repair bricks made from lunar soil using bacteria, a technology that may prove that this is crucial for maintaining structures built in lunar extreme environments.
NASA’s Artemis initiative illustrates the transition from lunar exploration to permanent settlement, and reducing dependence on the earth’s supply of building materials is crucial. Lunar Regolith is a powdery mixture of broken minerals and rocks that provides a viable on-site alternative.
Previously, IISC engineers developed a method for producing bricks from rock simulants using the bacteria Sporosarcina basteurii. This microorganism promotes the formation of calcium carbonate by metabolizing urea and calcium in the presence of guar gum, thereby effectively combining the soil into a hardened structure. The resulting bio-bricks provide a cost-effective and sustainable alternative to cement.
The team also used sintering, a traditional brick process that involved high-temperature heating of compacted rock mixed with polyvinyl alcohol. This technology produces bricks of special strength suitable for housing. “It makes bricks powerful, even for conventional housing,” explains Aloke Kumar, associate professor and corresponding author of IISC. “The scalability of sintering allows batch production in the furnace.
However, the moon surface presents extreme conditions, with temperatures between 121 oC and -133 oC and continuously exposed to solar radiation and microtransistor impact. These factors can induce structural cracks in sintered bricks. “Sintered bricks are fragile,” said IISC co-author Koushik Viswanathan.
To counteract this vulnerability, the researchers reintroduced Clostridium paste into the process. In a new study, they designed the defects in the sintered bricks and treated them with a slurry containing bacteria, guar gums and lunar soil mimics. Over a few days, bacteria produced calcium carbonate and secreted binder biopolymers in the cracks, effectively sealing the defects and restoring the original strength of many bricks.
“We were initially unsure whether the bacteria would bind to the sintered bricks,” Kumar said. “But we found that the bacteria not only consolidate the slurry, but also adhere well to other bumps.” Tests showed that the repaired bricks could tolerate temperatures from 100oC to 175oC.
Kumar [the carbonate production]? These things are still unknown. ”
To address these uncertainties, the team is preparing to include S. pasteurii in the upcoming Gaganyaan mission to assess its microgravity growth and activity. “If this happens, to the best of our knowledge, this will be the first experiment with this type of bacteria,” Viswanathan added.
Research report:Bacterial biological dirt can repair space bricks
Related links
Indian Academy of Sciences
Space Technology News – Applications and Research
