by Scott Schrage | University Communication
Burning rubber? Tired. Breathing rubber? Inspired.
The single-celled microorganisms known as methanogens are, no surprise, known for emitting methane: in the guts of humans and other animals, in hydrothermal vents that gash the ocean floor — almost anywhere, really, that oxygen is not.
But biochemist Nicole Buan and colleagues at the University of Nebraska–Lincoln have now genetically engineered a species of methanogen that can also yield sizable amounts of isoprene, the primary chemical component of synthetic rubber. Promisingly, that isoprene production substantially outpaces the yields of other microorganisms engineered for the same purpose.
“It’s the equivalent of if you or I just started breathing rubber,” said Sean Carr, a doctoral advisee of Buan’s. “That’s essentially what we made this organism do.”
Roughly 800,000 tons of isoprene, most of which go to the production of synthetic rubber, are refined from petroleum annually. A climate-conscious desire to reduce reliance on the fossil fuel has pushed researchers to seek alternative, renewable sources of the chemical. Among those alternatives are other types of single-celled microorganisms, including the more familiar yeast, the E. coli bacterium, and blue-green algae known as cyanobacteria.
As organisms, though, those sources require feedstocks to yield isoprene. Many of the feedstocks, especially glucose, are themselves expensive to produce or process on a large scale. Some of them come from corn, sugar beets or other crops that could otherwise be feeding people or livestock. And extracting whatever isoprene is produced can also mean designing and constructing new infrastructure, another pricey and labor-intensive proposition.
Which is partly why Buan had taken an interest in methanogens, which need no light, want no oxygen and readily devour otherwise worthless waste products — including wastewater, which they also happen to treat in the process.
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Nicole Buan
“They’re really incredible, really magical organisms,” said Buan, associate professor of biochemistry. “They can grow in a sealed glass vessel with just some minerals, and that’s it. To me, they had the highest potential for developing sustainable technologies that could really revolutionize our climate and energy needs.”
Read More:
https://news.unl.edu/newsrooms/today/article/engineered-microbe-excels-at-breathing-rubber-could-curb-reliance-on/