New Carbon-Silicon Bonds in Living Cells Point Toward New Forms of Life?

A recent study suggests that we are able to "coax" living cells into carbon-silicon bonds. This is the first time that we have seen that we can actually incorporate silicon, one of the most abundant elements on Earth, into the building blocks of living organisms.

However, it is important to point out that such bonds have been present before -- in electronics. People can find carbon-silicon bonds in paints, semiconductors, TV screens, and computers. According to Science Alert, it's only through these recent discoveries that we have figured out that carbon-silicon bonds can indeed exist in nature.

Silicon is the second-most abundant element in the Earth's crust after oxygen. However, scientists have found no indication of its involvement in any form of biological life.

This is why silicon can never be incorporated into any kind of biochemistry on Earth. This fact has puzzled scientists for a while because in theory, it would have been easy for silicon-based life forms -- and not carbon-based -- to evolve on the planet. This is because silicon and carbon have very similar chemical makeups.

Silicon and carbon share in the quality that they can form bonds with four atoms at the same time, meaning they can make long molecules needed to form the basis of life such as DNA and proteins.

However, according to New Scientist, the new discovery can bring a new foundation to what alien life may be on other planets. Caltech-based researcher Jennifer Kan affirmed that before their study, no living organism is known to put silicon-carbon bonds together.

It is also important to point out that Kan and her team were crucial in helping cells to form carbon-silicon bonds as it appears the cells could not have achieved this on their own. 

According to Caltech, the experiment is proof that these bonds can be present in the universe, given the right conditions.

They did this by isolating a protein naturally occurring in the bacterium Rhodothermus marinus in Iceland. The cytochrome c enzyme was chosen because of its ability to transport electrons through cells. Tests revealed these are the kinds of bonds that are able to attach silicon atoms to carbon.

After isolation, they inserted the gene for it into some E. coli bacteria to check if it could facilitate the production of carbon-silicon bonds inside its cells. 

The first iteration of the silicon-engineered bacteria did not do well, but they continued to mutate the protein gene within a specific region in the E. coli genome.

According to Aviva Rutkin, three rounds of mutations forced the protein to bond silicon to carbon 15 times more efficiently than any synthetic catalyst.This discovery is exciting primarily for two reasons. One, it offers a new way to produce carbon-silicon bonds needed to make pharmaceutical products, chemicals, and fuels. 

Second, it hints toward life-forms that could be silicon-based. And if researchers continue to do this research, they can get an understanding of what they could look like. 

Frances Arnold, one of the members of the team, said in a press statement that this is proof that nature can quickly adapt to new challenges. She said the DNA-encoded catalytic machinery of the cell can rapidly learn to promote new chemical reactions provided the right environment.