Scientists at the Indian Institute of Science (IISc) investigated how bacteria that can mold Martian soil into brick-like structures thrive in the presence of perchlorate, a toxic chlorine-containing chemical.
In a study published in PLOS One, the authors of which include Indian astronaut captain Shubhanshu Shukla, the authors found that while perchlorate slows the growth of bacteria, it also leads to the formation of stronger bricks.
According to IISc, bacteria that thrive on Earth may not make it to the alien lands of Mars, and perchlorate, which has been discovered in Martian soil during various space missions, is a potential deterrent.
Impact on the terrestrial organism
“Mars is an alien environment. What will be the effect of this new alien environment on terrestrial organisms is a very, very important scientific question that we need to answer,” said Aloke Kumar, associate professor in the Department of Mechanical Engineering and corresponding author of the study.
In previous studies, researchers have used the soil bacterium Sporosarcina pasteurii to build space bricks from lunar or Martian soil that can potentially be used to create alien habitats.
When the bacterium is added to synthetic Martian or lunar soil along with urea and calcium, it produces calcium carbonate crystals (precipitates) that help glue the soil particles together into bricks, in a process called biocementation. The process also requires the natural adhesive guar gum, a powdered polymer extracted from guar beans.
On Bengaluru soil
In the current study, the authors used a more robust, native strain of the bacterium that they discovered in the soils of Bengaluru.
IISc said that after first demonstrating its ability to form clots, scientists wondered if the strain could survive in the presence of perchlorate, which can be found at levels of up to 1% in Martian soil.
Working with Punyaslok Bhadury, a professor at the Indian Institute of Science Education and Research (IISER), Kolkata, the team found that bacterial cells become stressed in its presence, grow slowly, become more circular in shape and begin to cluster into multicellular structures.
More protein
Stressed bacterial cells also release more proteins and molecules into the environment in the form of extracellular matrix (ECM). Using electron microscopy, the researchers found that more calcium chloride-like precipitates formed and that the ECM formed small “microbridges” between the bacterial cells and the precipitates.
“When the effect of perchlorate is studied only on bacteria, it’s a stressful factor. But in bricks with the right ingredients in the mix, perchlorate helps,” said Swati Dubey, currently a doctoral student at the University of Florida and first author of the study.
As a building strategy
The team said it aims to deploy the method as an alternative, sustainable construction strategy that relies less on carbon-intensive cement-based processes — both on Earth and on Mars.
“Such technologies can also help facilitate future Mars landings by helping to build better roads, launch pads and landing sites for rovers,” said group captain Shukla.
Published – 30 Jan 2026 20:10 IST
