The images of the smallest bacteria to have ever ‘existed’ on our planet have been captured on microscope by researchers from the Lawrence Berkeley National Laboratory under the U.S. Department of Energy and University of California. The paper was published in the journal Nature Communications.
This cryo-electron tomography image, obtained from a 3-D reconstruction, of one of the cells. The interior of the cell looks densely packed. The darker spots are probably ribosomes. Scale bar: 100 nanometers. (Photo credits: Berkeley Lab)
Analysing the bacteria with electron microscopes
The scientists have been working on deciphering the bacteria for long now: the tiniest of bacteria known to men – they are believed to be the smallest form of life to have ever existed, or so do the researchers say – had triggered a controversy that lasted for around 20 years. They have now been documented by the researchers who analysed them with electron microscopes. Initially, the scientists were doubtful that these bacteria would be alive since they were found to be so small.
Description of the bacteria
The microorganisms are apparently ubiquitous, found mostly in groundwater. To the surprise of the researchers, the bacteria were easily spotted.
The bacteria look like densely packed spiral shapes similar to DNA.
They have only a few ribosomes. Their metabolism seems to be relatively minimal. Their subsistence depends on other bacteria.
150 of the cells fit into one cell of E-coli
The average volume of the bacterial cells has been estimated to be around 0.009 cubic microns. They are so small that 150 of them could fit into one cell of the well-known E-coli.
The researchers further explained their ‘tininess’ by comparing their size to that of a human hair: 150 000 of them can be made to fit onto the tip of a human hair.
Caught with filters
The bacteria were caught from groundwater with several filters of size 0.2 microns, the same ones used for water sterilisation.
The scientists stated that these bacteria might be contributing to the overall welfare of microbial ecosystems in ways yet unknown to us.
Our planet has always thrived with species of plants and animals that remain hidden from us. Perhaps, we have even smaller living organisms that we know nothing about. One of the authors of the paper, Birgit Luef, affirmed that their findings are not the result of a consensus of how minute a living thing can be, but they do constitute invaluable information as to the characterisation of the size and structure of extremely small cells.