Let's say you’re blind, and you’re swimming underwater (no worries, you can breathe under there), and you need to find some food. What strategy would you use to get to the food as fast as possible? Some bacteria have developed a strategy called "run and tumble" to solve this tricky problem. 1/6 ⚛️🧪 - ThreadSky

idontevencara.bsky.social • 38 days ago

Let's say you’re blind, and you’re swimming underwater (no worries, you can breathe under there), and you need to find some food. What strategy would you use to get to the food as fast as possible?

Some bacteria have developed a strategy called "run and tumble" to solve this tricky problem.

1/6 ⚛️🧪

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idontevencara.bsky.social•38 days ago

In the video above, you'll notice that for most of the time, most of the bacteria are moving in straight lines at constant speeds. This is the "run" phase of their movement. But then suddenly a little spindle sticks out, and the bacteria stop and change direction—that’s the "tumble".

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idontevencara.bsky.social•38 days ago

All the while, the bacteria are "smelling"—they sense chemical gradients that tell them food is nearby. If they sense the gradients are weakening, they stop running and decide to tumble. Rinse and repeat until the "smell" gets stronger and they find what they're looking for.

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idontevencara.bsky.social•38 days ago

This process seems to be well-tuned to the environments these bacteria tend to live in. The bacteria here achieve the "tumble" by rotating their flagella in the opposite direction from normal; if you put them in solutions with different fluids, the dynamics of the tumble change drastically.

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idontevencara.bsky.social•38 days ago

Further, it's robust to noisy environments, i.e. the bacteria don't have much trouble finding what they need even with lots of other signals around or with inconsistent food sources. There's also some evidence to suggest that the average direction change the bacteria achieve (~60°) is optimal.

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idontevencara.bsky.social•38 days ago

So even though it doesn't sound super efficient, these single-celled organisms managed to find an impressively successful solution to this otherwise difficult problem!

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idontevencara.bsky.social•38 days ago

References
https://www.sciencedirect.com/science/article/abs/pii/S1476927109000528
https://www.nature.com/articles/srep15761
https://www.annualreviews.org/content/journals/10.1146/annurev-fluid-122414-034606

tesmen.bsky.social•38 days ago

Unsure why it feels like me searching my socks

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