Tomas Tyml / The Regents of the University of California, LBNL
Bacteria usually live their tiny lives in the microscopic realm, but scientists have now discovered a gargantuan one the size and shape of a human eyelash.
The new discovery is “by far the largest bacterium known to date,” says Jean-Marie Volland of Lawrence Berkeley National Laboratory and the Complex Systems Research Laboratory. “These bacteria are about 5,000 times larger than most bacteria.”
“To put it into perspective,” he added, “it’s the equivalent for us humans of meeting another human who would be as tall as Mount Everest.”
The about 1 centimeter monster somehow attaches itself to leaves buried in the Caribbean mangroves, according to a report from the newspaper Science.
The scientist who originally collected the thin white filaments had no idea he had discovered a new type of bacteria visible to the naked eye.
But laboratory examination showed they lacked the essential characteristics of plant or animal cells, and genetic analysis soon revealed their true nature. They are related to other bacteria that also live on sulfur and grow, but not to this extent.
Olivier Gros/The Regents of the University of California, LBNL
Now called Thiomargarita magnificathese bacteria have yet to be cultured in the lab, so much about their way of life remains a mystery – including what advantage they gain in their underwater environment by growing to such prodigious size.
In addition to challenging old ideas about the maximum possible size, each of these bacteria organizes its insides in an unusually advanced way.
Instead of allowing the genetic material to float freely, as other bacteria do, these beings envelop and contain it in a kind of packaging. This is similar to what is done in more complex cell types, such as those that make up plants and animals.
Volland cautions that this doesn’t mean these bacteria are some kind of “missing link” between simple lifeforms and more complex lifeforms, saying it’s just a “fascinating example of a bacterium which has evolved to a higher level of complexity”.
Still, finding this bacteria inside, along with its incredible size, makes it “a truly magnificent discovery”, according to Thijs Ettema, a microbiologist at Wageningen University & Research who was not part of this research team.
“Researchers have identified a real ‘microbial monster,'” Ettema said in an email. “Their work highlights that the microbial world continues to amaze us!”
These bacteria can’t even rightly be called microbes, because microbes are by definition microscopic, points out Petra Anne Levin of Washington University in St Louis, who wrote a commentary accompanying the new report.
Additionally, while most bacteria reproduce by dividing into two identical cells, these long, filament-like creatures appear to reproduce by removing a small piece at the end which can then float away and continue to create a whole new being. .
And even though these organisms are so large that hundreds of thousands of smaller bacteria could fit on their outer surfaces, the researchers found that these surfaces appeared pristine, suggesting that these bacteria may be secreting some kind of antibiotic to ward off bacteria. smaller relatives.
The discovery of this bacterium “really opened our eyes to the unexplored microbial diversity that exists,” says Shailesh Date of the University of California, San Francisco and Complex Systems Research Laboratory. “Really, we’re only scratching the surface, and who knows what interesting things we have yet to discover.”