WEBVTT

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So this is a, let’s see if I get this right, Zetaproteobacteria. Correct.

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We’re focusing our efforts quite a bit on iron microbiology and we’re finding there’s an awful lot of iron that’s getting put into the oceans,

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basically fertilizing the oceans, that’s coming from hydrothermal vents.

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We’ve got our intact mat at the bottom here.

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Craig Moyer and his group are very interested in the iron-oxidizing microbial mats.

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There’s a little piece of intact mat.

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They’re kind of fluffy deposits that we see on the seafloor.

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It’s not that little. This is big.

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The iron mats are made up of what’s called iron ferrihydrite, primarily.

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They can also have some clays in them.

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They have a lot of polysaccharides, or microbial snot, and then there’s the cells that are actually doing a lot of the chemical transformations.

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That one’s kind of cool.

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So we brought up big chunks of the microbial mat, which we hope are intact, and then with the scalpel,

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we try to like, peel back layers, kind of, to show if there’s any directionality or orientation that we can see just by looking at it.

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I think it, like, this is the outside, right here, and they’re all coming, like, up.

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The bacteria are oxidizing iron, but what that’s basically doing is taking iron from the soluble form and converting it to a solid form.

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This was crotched by Margo Heygood as a gift for me for my master’s degree.

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So these are the cells of the Zetaproteobacteria on the end.

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So that bacteria is just this part?

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Yes.

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And everything else is just iron oxide?

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Yeah. And so all this is the iron oxide that the cells are producing.

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So this is not life size.

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No. But it’s a bit to scale. And it’s meant to represent what we know about the Zetaproteobacteria.

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Zetaproteobacteria seem to dominate all the iron systems in and around hydrothermal vents.

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They’re one of the main iron oxidizers that occur in the microbial mats in marine systems.

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The different bacteria make cool structures.

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Some of them twist, the iron comes out twisted, we call it a stalk.

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Sometimes it’s like a tube. We call that a sheath.

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So you can tell something about what was living there, like, based on what they make, what kind of structures they make.

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So the cell uses the iron oxides to move through the environment.

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Oh really.

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And it’s twisting as it’s doing that.

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And then as it’s gaining energy, growing larger, then it divides, and that’s what’s represented by…

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Oh, so these two guys used to be one, and now they’re two?

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Exactly.

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That is crazy.

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And when we look at the mats, you can tell which direction the mat was formed in by looking for these division points.

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Wow.

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When you see these nice mats on the bottom, they’re not just all microbiology, but it’s really the history of the microbes that have been there before them,

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as well as the ones that are actually growing right now.

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It is good in the lab where it’s a bit air conditioned, but it doesn’t quite fit around as a scarf.