Shapiro redux: from prey to predator (Introduction)

by David Turell , Wednesday, January 24, 2024, 19:17 (93 days ago) @ David Turell

Raied in hot or cold makes the switch:

https://www.newscientist.com/article/2413791-a-bacterium-switches-from-prey-to-predator...

Growing up at a different temperature seems to transform common prey bacteria into predators, suggesting that bacterial ecology is more fluid than we thought.

Two species of bacteria appear to reverse which is predator and which is prey depending on the temperature. Just a small temperature change is enough to cause the switch.

"The soil bacteria Myxococcus xanthus is a social species that hunts in packs – it forms temporary, multicellular “swarms” of individuals that chemically tear apart and soak up nutrients from other microbes. And its prey includes Pseudomonas fluorescens, a bacterium common in both soil and water.

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"...when P. fluorescens was reared at 32°C, M. xanthus destroyed most of the population within four days. But surprisingly, the P. fluorescens reared at 22°C “slaughtered M. xanthus to extinction”, Vasse and her colleagues wrote in the paper. They realised that cooler-reared P. fluorescens secreted a chemical compound that could degrade and destroy other bacteria.

"In addition, the team observed that P. fluorescens grew rapidly after wiping out M. xanthus. This means that it was probably consuming nutrients from, and thus preying on, its one-time predator.

“'[This research] challenges the idea of having ‘fixed’ roles within communities,” says Vasse. “They can change so fast, so easily and so radically. It’s very brutal.”

Comment: this study is no surprise to Dr. Shapiro. However, we should note, the species is still the same adapted species. Bacteria as free-living-alone organisms must have altered defenses they can bring into play.