Scientists made living cells from carbon-silicon bonds. This proves for the first time ever that nature can include silicon into the building blocks of life.
"No living organism is known to put silicon-carbon bonds together, even though silicon is so abundant, all around us, in rocks and all over the beach," says Jennifer Kan, a postdoc scholar and lead author of the new study from Caltech.
These carbon-silicon bonds have been seen before, but this is the first time they've ever been found in nature. They could be missing pieces to understanding silicon-based life in other parts of the universe.
[Image courtesy of Warut Roonguthai/Wikimedia]
Does this mean we're to expect silicon organisms now? Well, outside of Star Trek's Horta creatures, not yet. Carbon and silicon are chemically similar. They can both form chains easily thanks to their structure.
The research recently won Caltech's Dow Sustainability Innovation Student Challenge Award (SISCA) and showed that the bonds used in pharmaceuticals could be made more environmentally friendly.
Frances Arnold, Caltech's principal investigator of the study, said the team upgraded biology.
"We decided to get nature to do what only chemists could do - only better," Arnold said.
The researchers used directed evolution that creates new enzymes in labs by artificial selection. The goal not only improves the enzyme through evolution but also to convince the enzyme to make a silicon-carbon bond.
"It's like breeding a racehorse," said Arnold. "A good breeder recognizes the inherent ability of a horse to become a racer and has to bring that out in successive generations. We just do it with proteins."
Rendering of silicon-based lifeform [Image Courtesy of Lei Chen and Yan Liang for Caltech]
If we're not to expect silicon lifeforms on earth anytime soon, what can we expect? Well, any number of things. Pharmacy, agricultural and fuel specialists could use the processes to more efficiently make the carbon-silicon bonds they need for their products.
"This is something that people talk about, dream about, wonder about," said Annaliese Franz from the University of California, Davis to New Scientist. Franz was uninvolved in the research. "Any pharmaceutical chemist could read this on Thursday and on Friday decide they want to take this as a building block that they could potentially use."
This could also show that carbon traces might not be the only signs of life we should be looking for. If researchers continued to combine carbon-silicon bacteria, we might be able to predict or understand what they could look like.
You can read the entire paper, "Directed Evolution of Cytochrome c for Carbon-Silicon Bond Formation: Bringing Silicon to Life," on Science.