Prokaryote Lineages 2

cyanobacteria are gram negative photo autotrophs and many species actually performed nitrogen fixation. Now they are sometimes termed blue green algae. But this is a bit of a misnomer, as they are in fact, pro carry outs. Not you carry outs at all. They're actually the Onley bacteria that perform oxygen, IQ, photosynthesis. And it's pretty incredible because they're responsible for the origin of oxygen in the atmosphere. And you can see a nice, up close image of some cyanobacteria here. These are cyanobacteria that grow in filaments. Some grow is like free floating little cells and others form colonies. And you can see that this is a satellite photo here and this green mass here, that is just a cyanobacteria. That is a huge bloom of cyanobacteria. Um, you know, obviously generating ah bunch of oxygen because it's performing. Ah, bunch of photosynthesis. I mean, pretty amazing. This is a satellite photo, and there is so much of these tiny micro organisms rather so many of these tiny micro organisms that we can see it from space. And actually, the oldest fossils we have of life on Earth come from cyanobacteria. Uh, these air stromatolites, these blobs of what looked like rockets, actually calcium carbonate. And this is exuded by certain types of Santa bacteria on the and basically the oldest fossils we have of life on Earth are stromatolites from cyanobacteria, these air modern, uh, you know, living cyanobacteria. But we have stromatolites that look like these from, you know, over a billion years ago. It's amazing now. And also don't forget, lastly, that cyanobacteria are the organisms that were engulfed and eventually became chloroplasts. Now Act 18 acting a bacteria our high GC gram positive bacteria. And what that means is they have a large, uh, a high percentage of guanine cytosine right GC from DNA in there chromosome. So they have a high GC content, so to speak, their grand positive bacteria. And they include the genus stripped in my sees, which is responsible for many antibiotics. Uh, many antibiotics have come from this genus of act in a bacteria. Now, these were initially mis classified as fungi because they have a fungus like morphology. And as you'll see in the name, it ends with my sees. Uh, what you'll see once we are when we discuss fungi is that, uh, the names of the Latin names for fun. Guy end in my sees. So these were initially thought to be fun guy, Actually, bacteria. Now the misclassification comes from the fact that chains of cells form these branching my Celia. And it's these structures that caused biologists to think that these were actually fun guy. Lastly, we have the firm equities which are low GC gram positive bacteria. So thes high GC is basically in comparison to these low G C bacteria, and this actually includes This group includes the genus lacto bacillus, which is super important to humans. Not on Lee. Are they responsible for yogurt production? Obviously very important, and also they're involved in cheese production. Very important, and most important to me, they're involved in sour beer production. If you've never heard of sour beer, you strike. It's delicious. Andi. It involves fermentation with lacto bacillus to help get that lactic acid kind of sour flavor. Additionally, there are many species of lactobacillus that live inside humans that are super important. Um, for our health, I mean many species live in our gut. Help us with digestion. There are species that live in the vagina that help maintain that environment, and that's actually what this image is from this is a human cell, and you can see this is a human cell and you can see all these little dark rods. Those are lacto bacillus and they our species of lactobacillus that live in the vagina. All right, that's it.