Scientists have discovered the world’s largest known bacterium in the form of a white filament the size of a human eyelash in a swamp in Guadeloupe.
A strange creature about 1 cm in length, Thiomargarita MagnificaIs about 50 times larger than all other known giant bacteria and is first visible to the naked eye. Fine white threads were found on the surface of rotten mangrove leaves in shallow tropical marine swamps.
This discovery was surprising because bacteria should not grow this large according to a model of cell metabolism. Earlier, scientists had proposed a size limit of about one-hundredth of a new species.
“To explain the situation, it’s like encountering another person as high as Everest,” said Jean-Marie Voland, a scientist at Lawrence Berkeley National Laboratory, who co-authored the study. increase.
The organism was discovered by Olivier Gross, a professor of marine biology at the University of Antilles in Guadeloupe, looking for symbiotic bacteria in the mangrove ecosystem.
“When I saw them, I thought: weird,” Gross said. In the lab, we first performed a microscopic analysis to confirm that the strands were a single cell. A closer look also revealed a strange internal structure. In most bacteria, DNA is free to move around inside the cell. Thiomargarita Magnifica It seems to keep that DNA more organized within the membrane-bound compartment of the entire cell. “And this is very unexpected for bacteria,” Volland said.
Bacteria have also been found to contain three times as many genes as most bacteria, with hundreds of thousands of genomic copies spread throughout each cell and become unusually complex.
Scientists still don’t know how bacteria have evolved and grown so large. One possibility is that it has adapted to avoid predation. “When it’s hundreds or thousands of times larger than a predator, it can’t be consumed by the predator,” Volland said.
However, growing means losing some of the traditional benefits of bacteria, such as being able to move around on their own and colonize new niches. “By leaving the microscopic world, these bacteria have definitely changed the way they interact with their environment,” Volland said.
Bacteria have not yet been found elsewhere and have disappeared from their original location when researchers recently returned, probably because they are seasonal organisms. However, in a paper published in Science, the authors conclude that the finding “suggests that larger, more complex bacteria may be hidden in clear vision.” increase.