The original version of This story appears in Quanta Magazine.
Prochlorococcus Bacteria are so small that you have to manage a thousand of them to fit the thickness of a human grandchild. The ocean sees with them: the microbes are probably the most abundant photosynthetic organism on the planet, and this creates a significant part – 10 to 20 percent – of the oxygen of the atmosphere. This means that life on earth depends on the approximately 3 octillion (or 3 × 1027) Small individual cells away.
Biologists once thought of these organisms as isolated wanderers, who are in an unfathomable expanse. But the Prochlorococcus The population can be more connected than anyone could imagine. They may have conversations over broad distances, and not only fill the ocean with envelopes of information and nutrients, but also connect what we thought they were private, inner spaces with the interior of other cells.
At the University of Córdoba in Spain, not long ago, biologists saw images of the cyanobacteria under a microscope that grew a long, thin tube and grabbed its neighbor. The image made them sit upright. It came to them that it was not a wave.
“We realized that the cyanobacteria were linked to each other,” says María del Carmen Muñoz marín, a microbiologist there. There were links between Prochlorococcus cells, and also with another bacterium called Synechococcus, often living nearby. On the images, silver bridges linked three, four and sometimes 10 or more cells.
Muñoz marín struggled about the identity of these mysterious structures. After a battery tests, she and her colleagues recently reported that these bridges are bacterial nanotubes. Bacterial nanotubes were only observed in a general laboratory bacterium only 14 years ago, and are structures of cell membrane that allow nutrients and resources to flow between two or more cells.
The structures have been a source of fascination and controversy over the past decade, as microbiologists have worked to understand what leads to them forming and what exactly moves under these network cells. The images of the Muñoz marín laboratory were the first time these structures were seen in the cyanobacteria responsible for so many of the earth’s photosynthesis.
They challenge fundamental ideas about bacteria, and raise questions such as: how much cost Prochlorococcus Share with the cells around it? And does it really make sense to think about it, and other bacteria, as single cell?
Completely tubular
Many bacteria have active social lives. Some make Pilei, hair -growing protein that connects two cells to enable their DNA. Some form dense plaques, known as biofilms. And many emit small bubbles, known as vesicles containing DNA, RNA or other chemicals, such as messages in a bottle for whatever cell to intercept it.
These were vesicles on which Muñoz marín and her colleagues, including José Manuel García-Fernández, a microbiologist at the University of Córdoba, and graduated student Elisha Angulo-Cánovas, were looking for as they searched Prochlorococcus and SYNECHOCOCCUS in a dish. When they saw what they suspected was nanobuis, it was a surprise.