Bacteria as natural biofactories

SynCell News • May 21, 2020

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umankind has relied on bacteria for millennia. From fermentation processes, such as baking or brewing, to chemical manufacturing of enzymes or pharmaceutical compounds as antibiotics, vaccines, or steroids, passing through the energy bio-fuels industry or agriculture. Bacteria have always been in our lives in one way or another.

Bacteria can generate nanomaterials.

Thanks to genetic engineering, we dream of a future in which creating bacteria that eat plastic, emit light, and even tell us about our health will be possible. When it comes to microbes, big things come from small packages. However, why not going even farther? Or smaller.

Bacteria wander around the micrometer scale can generate nanomaterials with different compositions, morphologies, and features. The bacteriogenic (or bacteria mediated) synthesis of nanostructures has raised as one of the most novel and promising facets within Green Nanotechnology.

However, long before this natural behavior caught the scientific community’s attention, bacteria were able to produce nanostructures as a survival way.

How do bacteria produce nanostructures?

The natural distribution of minerals and, nowadays, human contamination, are responsible for numerous localized mineral deposits with a high concentration of metals all over the planet. These deposits are named ores when the raw material can be profit upon extraction using different techniques. Not looking for a benefit, but for spreading out and survive, bacteria reached the Earth’s crust long before humans did.

As they evolve and adapt quicker than any other living organism, bacteria could alter the chemical nature of the toxic metallic elements, so there was no longer a concern about toxicity. Therefore, after a few biochemical reactions, bacteria were naturally able to cope with the toxicity of metallic ions and generate harmless nanoparticles without effect for them. All of that just happened as a byproduct of their survival.

Bacteria evolve and adapt quicker than any other living organism

This new behavior caught the attention of the scientific community in the 1950s, when Kenneth Temple discovered that the rod-shaped Gram-negative bacteria Acidithiobacillus ferrooxidans prospered in iron, copper, and magnesium-rich environments. In Temple’s experiment, the bacterium was inoculated into media containing a concentration of iron 433 times more significant than the one able to kill a man. Temple discovered that the bacteria grew faster in high iron concentrations. The byproducts of bacterial growth caused the media to turn very acidic, in which the microorganisms were still able to reproduce.

This was the first experiment proving that microorganisms have mechanisms for sensing and taking up metals. But how does it happen? Microbial cells need metal ions as cofactors for the proper functions of several biochemical processes. Nonetheless, high concentrations of these ions might interfere with enzymatic functions, becoming extremely toxic and leading to cell death. Therefore, bacteria can develop metalloregulatory mechanisms, which allow them to generate metallic nanomaterials as a byproduct.

Using this natural, smart, and extremely old detoxification mechanism of bacteria, SynCell Biotechnology has designed, tailored, and implemented synthetic devices that allow our bacterial species to produce valuable nanomaterials with incredible biomedical applications.