According to a study published Thursday in the journal Science, a newly discovered bacterium has been found in Guadeloupe, the Lesser Antilles, that is large enough to be visible to the naked eye and resembles the shape and size of a tab.
Thiomargarita magnifica, a reference to its exceptional size, has an average cell length greater than 9,000 micrometers, which is almost 1 centimeter (0.4 inches) long. The cells of most bacterial species are about 2 micrometers long, although the largest can reach 750 micrometers.
T. magnifica can grow up to 2 inches long, according to study co-author Jean-Marie Volland, a marine biologist and scientist at the California Complex Systems Research Laboratory and affiliated with the Department of Joint Genome Institute. ‘US Energy.
“To understand how giant a bacterium is, it’s the same as finding a human as tall as Everest,” he told CNN on Wednesday.
More than 625,000 E. coli bacteria could fit on the surface of a single T. magnifica. However, despite its size, the bacterium has a “remarkably pristine” surface, devoid of the bacteria that live on the surface of living plants and animals, according to the study.
How do you maintain your size?
It was previously thought that bacteria could not grow to a size visible to the naked eye due to how they interact with their environment and produce energy.
But T. magnifica has an extensive network of membranes that can produce energy so that it does not depend only on the surface of the bacterium to absorb nutrients through its cell. Volland was able to visualize and observe the giant cells in 3D with the help of hard X-ray tomography, confocal laser scanning microscopy and transmission electron microscopy, according to a press release.
Unlike most bacteria, which have genetic material that floats freely within their single cell, a T. magnifica cell has its DNA contained in small sacs that have a membrane, called cucumbers.
“This was a very interesting discovery that opens up a lot of new questions because it’s not something that is classically observed in bacteria. It’s actually a feature of more complex cells, the type of cells that make up our bodies, or animals and plants “. said Volland. “We want to understand what these cucumbers are and what they do exactly, and whether they play a role in the evolution of the gigantism of these bacteria, for example.”
T. magnifica was first discovered growing as thin white filaments on the surface of decaying mangrove leaves in shallow tropical marine mangrove swamps in Guadalupe, according to the study.
These giant bacteria grow in sediments at the bottom of sulfurous waters, where they harness the chemical energy of sulfur and use the oxygen in the surrounding water to produce sugars, according to Volland. T. magnifica can also make food from carbon dioxide.
It has been suggested that by being much larger than the average bacterium, a T. magnifica cell could have better access to oxygen and sulfur from its environment at the same time, according to Volland.
It is also possible that the amplitude of T. magnifica cells compared to other microbes in the bacterial population means that they do not have to worry about being eaten by predators.
A microbial “black box”
Tanja Woyke, a senior scientist at Lawrence Berkeley National Laboratory in California, believes it is likely that giant bacteria, or related species, can be found in other mangroves around the world.
“I’m always struck by how little we know about the microbial world and how much there is,” he told CNN on Wednesday, adding that the microbial world “is still a black box.” Woyke, who heads the U.S. Department of Energy’s microbial genomics program, is one of the study’s senior authors.
“Viral size-related confirmation bias prevented the discovery of giant viruses for more than a century,” the study concluded. “The discovery of Ca. T. magnifica suggests that larger, more complex bacteria may be hidden from view.”
“Just because we haven’t seen it yet, doesn’t mean it doesn’t exist,” Woyke added.