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Largest ever bacterium discovered - it can be 2 cm big

puskas78

puskas78

english.elpais.com

Scientists discover one-centimeter long bacterium that’s visible to the naked eye

The organism, identified by a Mexican scientist in a Caribbean mangrove, challenges the very definition of what a microbe is
english.elpais.com english.elpais.com

www.nature.com

Daily briefing: Largest bacterium ever discovered is 2 cm long

Thiomargarita magnifica has a thread-like single cell up to 2 centimetres long and keeps its genetic material in a membrane sac. Plus, nations are convening for a plastic-pollution treaty and evidence that the dinosaur-killing asteroid struck in springtime.
www.nature.com www.nature.com

newatlas.com

Largest bacterium ever discovered is longer than a housefly

Biologists have discovered the largest bacterium ever found, with a single cell measuring a mammoth 2 cm (0.8 in) long. Visible to the naked eye, this new species has some bizarre characteristics that make it like a missing link in the evolution of complex cells like those in humans.
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Its average size is 9 mm but 2 cm specimens have been observed.

This gigantic size completely upends the accepted scientific understanding of how big bacteria could possibly get.
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So how does the giant new bug pull this off? It actually contains a water-filled sac that makes up 73 percent of its volume, which pushes its cellular contents up against the outer membrane, so vital molecules don't have to travel across its entire width.
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Suddenly that "silly" macrovirus episode of Voyager doesn't feel so silly...
Another very large species uses a similar mechanism.

But the bizarre bacterium only gets stranger. This DNA was packaged inside a membrane sac, something that's normally characteristic of more complex lifeforms – bacteria normally have their DNA floating free through the cell. This blurs the line between the two main classifications of lifeforms, prokaryotes and eukaryotes.
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Or it's a missing link?
 
... did we just find a missing link?

Or, well, something with shared derived traits from a missing link?
 
Well the current hypothesis on where the Cell Nucleus came from as a structure, was that it was an endosymbiosis event where an Archea ended up living inside a bacterium.

So rather than a missing link, this is more like, a different evolution of a broadly similar structure.

Frankly, the other structure, the "pepin" sac which inflates the innards against the cell wall, seems more likely to be a pointer in how the endoplasmic reticulum evolved? Sounds like a super-inflated vacuole basically.

The article mentions it's named after sulfur nodules, which implies to me it has an Iron-Sulfite metabolism, which is the "normal" way to do obligate anaerobic activity. (That it grows in detrious in the bottom of a mangrove swamp also makes me think that -- easy for the water to striate and go hypoxic).
 
When I read the title I thought maybe they just found a slightly bigger version of Thiomargarita Namibiensis, I didn't expect over a centimeter- though it still is in thin filaments so it's not THAT impressive by volume if I'm reading this right. What's really interesting is the pseudo-nucleus. It's definitely no missing link (since it's a bacteria rather than a cousin/member of Eukarya or Archaea), but it's definitely fascinating- interesting that (if I'm reading the original paper correctly) the ribosomes are inside the compartment with the DNA.
 
Single called organisms being significantly larger compared to other single cell is not exactly something novel. Acetabularia is a species of single celled plant that's about 0.5 to 10 cm tall. What's astronomical about this discovery is that this is the first case of a extremely large bacterium being discovered that far exceeds prior discoveries in size.
 
General_Urist said:
It's definitely no missing link
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Note that in order for it to be established as a missing link, we need to show DNA replication as well as the act of translation and transcription being done in a way that seems to halfway between bacteria and archaea. This is because Archaea and Eukaryotea use very similar methods to do the above 3. So unless it shows its transitioning into being Archaea like?

We cant call it a missing link.
 
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