Futuristic marine and space research

Microorganisms as concrete builders

The beginning of space research dates back to the launch of Sputnik 2 by Soviet Union that carried the dog named Laika. Further interest in space research developed with the first man landing on moon. Since then several researches are being conducted to study the outer space. Recently, the whole world has witnessed the success of Mangalyaan and Chandrayaan 3 launched by ISRO. Currently nine astronauts are on board the International Space Station (ISS) through NASA. The astronauts as well as the space craft face several challenges in the outer space due to the microgravity and cosmic radiation. These radiations pose great health hazards to the astronauts and also lead to the destruction of the space craft and the sensors. So, to combat these effects several extremophile microorganisms are used to create concretes that protect the spacecraft as well as the astronaut in it. Concretes are also used to build up settlements on space stations that mimic the lunar or martial atmosphere.

Concretes are promising materials that protect living organisms from radiations. These are made of water, cement and sand and gravels. The strength of these concretes can be increased by mixing human serum albumin or bovine serum albumin along with urea. This is where the microorganisms come into play. Recombinant bacteria producing human or bovine serum albumin can be used to produce large quantity of albumin that can be used to produce concretes. Further the precipitation of calcite which is the main component of limestone and cement is used to produce concrete. Certain extremophiles like Sporosarcina pasteurii, a highly urease active bacteria, precipitate Calcium Carbonate by urea hydrolysis or CO2 concentration, is used to produce concrete. Concretes made of regolith and cement might produce cracks with time that allows the radiations to pass through. The concretes made with the help of bacteria are self-renewable as these bacteria ( etc.) can repair the cracks by precipitation of calcium carbonate crystals within the cracks. These bacteria have the ability to withstand the harsh conditions of the concrete like high pH (pH=12). This property is due to the formation of spores by bacteria like Bacillus sp. Hence, these extremophiles are well capable of combating the extreme conditions of space. Concretes are a major part of space research for the development of radiation tolerant spacecraft and human settlements on Martian and Lunar atmosphere. Thus the building of strong and self-healing concretes is highly essential for protection of astronauts on space.

Recent space research focuses on human settlements on Mars and moon. At this juncture, radiation resistant concretes are highly essential that can provide a promising tool for settlemens on Lunar and Martian conditions and International Space stations (ISS). The engineered microorganisms pave a promising pathway for the development of concretes that are durable, self-renewable and resistant to radiations that provide gateway to future space research.

Tanni Datta

University/College name : Utkal University