They discover giant bacteria that can be seen with the naked eye

MADRID (El País): An international team of scientists has discovered a bacterium about one centimeter long In the mangrove forests From the French island of Guadeloupe, in the Caribbean Sea. The unusual object can be seen with the naked eye, so it is in contrast same definition germ: “a single-celled organism visible only under a microscope.” bacteria called The wonderful theomargariteThey were identified by Mexican microbiologist Silvina Gonzalez Rizzo, of the University of the Antilles, in Pointe-a-Pitre.

The usual size of bacteria is about two thousandths of a millimeterwith exceptions of about 180 millimeters (slightly less than the thickness of the paper), such as Thiomargarita namipensisFound in Namibia in 1999. A newly discovered organism averages 9,000th of a millimeter, roughly a centimeter.. It is about 50 times larger than the bacteria hitherto considered giant, according to the researchers, who have only published a tentative draft of their analysis so far. A copy of The wonderful theomargarite The longest among those found reaches two centimeters.

Microbiologist Sylvia J. Organisms have traditionally been divided into prokaryotic organisms, such as bacteria, and eukaryotes, such as humans. The main difference is that eukaryotes consist of cells that have their own instruction manual, DNA, in a differentiated, membrane-enclosed nucleus. In bacteria, on the other hand, DNA floats freely. The biggest surprise is that a file The wonderful theomargarite It has structures reminiscent of a nuclear membrane, according to Asinas, a researcher at the Institute of Marine Sciences (affiliated with CSIC) in Barcelona who was not involved in the study.

Amazing new bacteria. Its instruction manual contains nearly 12,000 genes, three times the usual number, and the organism possesses half a million copies of this genome, an “unprecedented” amount, according to the discovery’s authors. For Acinas, a lifelong co-author of discovering thousands of new species of microbes, The wonderful theomargarite It’s a “brilliant example” of investigating the evolutionary mechanisms that drove these bacteria to be as such in an ecosystem as unique as mangroves, which are lands populated by tropical shrubs that are tolerant of saltwater.

At least 600 million years ago, life on Earth moved from simple, single cells to multicellular organisms, which ended up evolving into complex organisms like humans, made up of 30 billion perfectly coordinated cells. Silvina González Rizzo’s team recognizes that “the origin of biological complexity is one of the most important, and still unanswered, questions in biology”. Unusual features of The wonderful theomargarite It has elicited numerous reactions from the scientific community. Japanese biologist Kazuhiro Takemoto of the Kyushu Institute of Technology proposed in the magazine to know That new bacteria Could be the ‘missing link in complex cell evolution’.

Biologist Inaki Ruiz Trillo is more cautious. “It’s not the missing link,” says this scientist, head of a laboratory at the Barcelona Institute for Evolutionary Biology that researches the origin of multicellular animals. “It is not something intermediate between prokaryotes and eukaryotes. Nor is it an intermediate between unicellular and multicellular organisms. It is nothing in between, because it is not in an intermediate region on the tree of life.” It is a breed that has evolvedNow they’ve found out which is great, but that’s all there is to it,” says the Spanish biologist.

Ruiz Trillo believes that the strange intracellular membranes of The wonderful theomargarite It may be the result of evolutionary convergence, the phenomenon by which similar structures, such as the wings of bats and butterflies, appear independently. “These bacteria have grown larger, because they have worked to their advantage ecologically, and as they have increased in size they have developed certain characteristics, such as partitioning, which, for whatever reason, work better for them,” Ruiz Trillo says. “It’s brutal it’s a large bacterial cell. It breaks your schemes on all sides,” he adds.

Marine biologist Olivier Gros, of the University of the Antilles, discovered microbial filaments in sunken leaves in a mangrove swamp on Guadalupe Island a decade ago, but it was his colleague Silvina Gonzalez Rizzo who realized five years ago that it was one. bacteria. It was a Mexican microbiologist who chose the scientific name The wonderful theomargarite, which means “large sulfur pearl”, referring to its granular structures with sulfur. Biologist Jean-Marie Voland, from the Complex Systems Research Laboratory (USA), led the in-depth analysis of the organism.

The authors believe that no more giant bacteria were found because of what’s called confirmation bias: the tendency to search for results that confirm personal beliefs. Nobody was looking for centimeter-sized bacteria. “Discovery The wonderful theomargarite It suggests that larger, more complex bacteria may be hiding in plain sight.”

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