The world’s smallest life-form is a tiny bacteria that is virtually invisible to the naked eye, but a team of scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California has recently managed to capture a detailed image of it and give us a peek of the smallest life-form on the planet. The picture may not look like much, but it’s a shot of an ultra-small bacteria that is considered to be “about as small as life can get.”
[Image Source: Berkeley Lab]
Despite being extremely abundant on the planet, the bacteria is still a mystery to scientists, who don’t yet fully understand its role in the ecosystem. That’s because studying it was considered impossible; not only for it’s incredibly small size, but also because it is extremely fragile and dies quite easily.
“They’re enigmatic. These bacteria are detected in many environments and they probably play important roles in microbial communities and ecosystems. But we don’t yet fully understand what these ultra-small bacteria do,” explained Jill Banfield, one of the researchers who captured the images using cryogenic transmission electron microscopy.
The scientists managed to preserve the live samples by freezing them at a temperature of -272° C, before transporting them to the laboratory for analysis. After placing them in an environment with controlled conditions, the cells were analyzed using 2-D and 3-D cryogenic transmission electron microscopy.
These cells have an average volume of 0.009 cubic microns (one micron is one millionth of a meter), which means more than 150,000 cells could fit onto the tip of a human hair!
“There isn’t a consensus over how small a free-living organism can be, and what the space optimization strategies may be for a cell at the lower size limit for life. Our research is a significant step in characterizing the size, shape, and internal structure of ultra-small cells,” says Birgit Luef, a former postdoctoral researcher in Banfield’s group who is now at the Norwegian University of Science and Technology, Trondheim.
According to Banfield, the record is extremely significant because it marks the beginning of research on ultra-small organisms.
“These newly described ultra-small bacteria are an example of a subset of the microbial life on earth that we know almost nothing about,” says Banfield.