Researchers from the Indian Institute of Science (IISc) and the Indian Space Research Organization (ISRO) have developed a modular, stand-alone device for cultivating microorganisms, which could allow scientists to conduct biological experiments in the ‘space.
In a study published in “Acta Astronautica,” the team showed how the device can be used to activate and track the growth of a bacteria called “Sporosarcina pasteurii” over several days, with minimal human involvement, IISc said. , based in Bengaluru in a statement. .
Understanding how these microbes behave in extreme environments could provide valuable information for manned space missions such as “Gaganyaan”, India’s first manned spacecraft planned by ISRO, he said. In recent years, scientists have increasingly explored the use of lab-on-a-chip platforms that combine numerous analyzes into a single integrated chip for such experiments. But there are additional challenges to designing such platforms for space, compared to the lab.
“It has to be completely self-sufficient,” said Koushik Viswanathan, assistant professor in the department of mechanical engineering and lead author of the study. “Also, you can’t just expect the same operating conditions as in a normal lab … and you can’t have something that consumes 500W, for example.”
The device developed by the IISc and ISRO team uses a combination of LED sensors and photodiodes to track bacterial growth by measuring optical density or light scattering, in the same way as spectrophotometers used in the laboratory. It also has separate compartments for different experiments.
Each compartment or “cassette” consists of a chamber where bacteria – suspended as spores in a sucrose solution – and nutrient medium can be mixed to restart growth, by flipping a switch remotely. The data for each cassette is collected and stored independently.
Three cassettes are clubbed into a single cartridge, which consumes just under a W of power. Researchers predict that a full payload that can be loaded onto a spacecraft will contain four such cartridges capable of performing 12 independent experiments. The team also had to ensure that the aircraft was waterproof and immune to any change in orientation.
“This is a non-traditional environment for the growth of bacteria. It is completely waterproof and has a very small volume. We had to see if we would get consistent (growth) results in this smaller volume, ”said Aloke Kumar, associate professor in the department of mechanical engineering and other senior author. “We also had to make sure that the LED on and off didn’t generate a lot of heat, which can change the characteristics of bacterial growth. Using an electron microscope, the researchers were able to confirm that the spores grew and multiplied into rod-shaped bacteria inside the device, as they would under normal conditions. normal in the laboratory, according to the release.
“Now that we know this proof of concept works, we’ve already taken the next step: preparing a flight model (of the device),” Viswanathan said. This would include optimizing the physical space the device can occupy and its performance under stresses such as vibration and acceleration due to gravity. The apparatus can also be adapted to study other organisms such as worms, and for non-biological experiments.
“The idea was to develop a model platform for Indian researchers. Now that ISRO embarks on an ambitious manned space mission, it must find its own, home-made solutions, ”said Kumar.