This is Scientific Americans' 60-Second Science. I'm Sarah Mytek.

Modern medicine and bacterial pathogens are in an arms race. We use antibiotics to keep

them at bay, and then they adapt to become immune to those antibiotics, evolving into

super bugs. The battle has been an asymmetric one. We just don't have that many options

in the fight. Most of our antibiotics come from bacteria, the vast majority from a single

genus, streptomyces. And most antibiotics use the same handful of strategies to attack

bacteria. But there's a reason that we only use a tiny fraction of the antibiotic

chemicals that exist in nature.

This search for completely new substances was unsuccessful for the past 30 years. It's

very difficult to make sure that we find an antibiotic, so a substance that's produced

by microorganisms and that's toxic to other microorganisms, but that is not toxic to humans.

Miriam Rosenbaum is a professor of synthetic biotechnology at the Hans-Nol Institute in

Germany. But how, if they're so hard to find, do scientists know that we have only found

a tiny fraction of the antibiotic substances that exist in nature?

We do know that because for the past 20 years, we were under this biological revolution

of sequencing. Researchers like Rosenbaum have taken that revolution underground, literally,

like into the dirt. And so with this environmental sequencing campaigns, we found out that actually

the microbial road is much more bigger than we thought it is. This is how we know that

we only have 5% in the lab, because we see just looking at the DNA in the solar cell,

but we see there are 95% more than we already. We don't have the cells. We can know more

than their name or more than their existence there. We see what genes they have.

They don't have the cells because only about 1 to 15% of the species of bacteria in nature

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