From the brains behind brains on, this is the Moment of Um. Moment of Um comes to you from APM Studios. I'm Ruby Guthrie.

You might not know this about me, but I'm obsessed with anything and everything miniature. I collect mini toys,

like teeny animals or adorable little foods. In fact, I used to paint miniature figures and make

tiny scenes inside little mint and candy tins. I love all things mini. And you know what is extremely many? Microorganisms,

or microbes for short. They're tiny microscopic living things like bacteria, and they are everywhere.

Microbes in our gut help us digest foods. Microbes also help make some of my favorite

foods, including bread and cheese. And with all the hard work that microbes do, I wonder if they

ever get tired. Like, do they ever rest? Listener John had this question, too. Do microbes ever sleep?

We say in class, the dream of a bacterium is to become another bacterium. My name is Daniel Bond.

I'm a professor of microbiology at the University of Minnesota. I study cool bacteria. When they sleep,

that would mean that they're probably, they're just not eating. They're not metabolizing. But a lot of bacteria have resting states, ways that they can rest so that their

cells won't break down so that they're ready when things get better. A lot of cells can go into a state

that can be dried that's like a spore. So this thing can last hundreds of years in a dry state. And then when

it finds water and nutrients, the bacteria can emerge and start growing again. So they could be

growing very, very slowly or waiting for that moment when the nutrients come by. So yeah, they

have a lot of ways to rest because they probably spend most of

their time waiting for things to get better. They don't sleep, but a lot of bacteria have what we

call circadian rhythm. They know when it's night and day. And so if you go out and take a sample of

bacteria from the ocean at night, a lot of those bacteria will wake up in the sense of they'll start turning on genes and switching their metabolism to things that they're going to need when the sun comes up.

So that when the sun is up, they're making the proteins and the machines they need to harness the sunlight. But at night, when

there's no sun, they need to do something different. And so they will turn those genes off. And so

even when you take them out and you put them in the dark, they'll continue this rhythm.

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