Meetings of the American Chemical Society never disappoint. In them, you can see first-hand some of the most innovative initiatives in the sector, and the last one, held in Washington DC, has been no exception. Thus, among the myriad of studies that have been presented –their leitmotif has been the impact of this discipline on the global economy–, we have learned about the development of biodegradable compounds capable of absorbing some of the toxic substances that are destroying corals; that of silk sensors that can be easily integrated into any garment; or a striking proposal that proposes converting the waste left by astronauts, such as their urine or the carbon dioxide that they exhale when they breathe, into very different tools.
Mark A. Blenner, professor of Chemical and Biomolecular Engineering at Clemson University in South Carolina, coordinates the group of students and researchers working on this latest project. In his opinion, the conversion of debris will be a key technology that will facilitate long-duration manned space travel , in which astronauts will not be able to receive new equipment or spare parts: “If they are going to embark on a journey of several years, we will have they have to find a way to reuse and recycle everything they carry, “he says. In such an adventure, nothing would go to waste, not even their own organic waste or the gases they exhale.
To convert these molecules into other useful products, such as nutrients and polyesters, Blenner and his colleagues propose using different microbes. “Take omega-3 as an example , an essential fatty acid that our bodies cannot make from other substances. It can be kept for about two years, so many of those long flights will require more to be manufactured on board. of the ship or when it reaches its destination. The idea is that they have biological tools that allow them to do so “, explains the scientist.
These include several strains of the yeast Yarrowia lipolytica , which require nitrogen and carbon to grow. Both compounds, according to Blenner, can be found, respectively, in urine and in the carbon dioxide that we expel when we breathe . In order for yeasts to take advantage of the latter, scientists would add cyanobacteria, microorganisms capable of photosynthesis. Researchers can adjust the process so that one of the strains produces the aforementioned omega-3, but also certain monomers, elemental chemical units that can combine with others to form other compounds, such as polyesters.
These polymers can be used as raw material in a 3D printer – a tool that all missions to space will incorporate – to obtain plastics and fibers with different properties. In fact, Blenner and his team have announced that they will continue to study how to modify Y. lipolytica to produce different monomers. “We have observed that this organism differs quite a lot from other yeasts in its genetics and biochemical nature,” says Blenner. “What’s more, each one presents some peculiarity that, if we want to take advantage of it, we must know in depth.”
Image: American Chemical Society
