 Okay, everybody, Dr. O. This video I want to talk about the formation of biofilm. So there's significance matters a lot more to me, but I think this is still important to talk about. So a couple of terms before we jump in, you're going to hear me use the terms planktonic cells and sessile cells. So planktonic cells are the free-floating individual cells that are living out and about. And the sessile cells are the ones that have actually attached to the surface and begin the formation of a biofilm. And then, of course, those sessile cells can become a planktonic cell again and leave a biofilm. So the function of biofilms is going to be, besides all the protection and everything I covered in the other biofilm video, is going to be an attachment so the microbes can live in a community in a surface. And oftentimes, these surfaces are going to have moving water or material by them. So they need an attachment point. So that's what happens. The first step of biofilm formation is this attachment. So the planktonic cells are going to find some sort of organic matter to attach on to. So I could be like a rock or something like that. But they're going to find this home, this attachment point. And then they're going to really, really anchor in. Now you can see this becomes an irreversible process. And they anchor in and form the foundation of this biofilm that's going to form this entire community. And then we just have growth and growth and growth. These cells grow. The biofilm is going to continue to grow. Maybe you've seen that. Get the slime on the rock or slime in a pail you have in your backyard or something. So over hours and days, these cells are going to continue to grow and divide and form this larger and larger community. But it is a very complex community. Like you see here with step number four, you've got this big, thick coating, this extracellular polymeric substance, this like, I like to give it as a capsule over a large community. This thick capsule forms on the outside and on the inside you have channels for water and air and these kinds of things. It is like they're basically forming a microbial city. And it is also important to note it's a community. These are not all the same organisms. They're not even all bacteria. So different types of organisms are going to be working together. And I'll talk in another building about another building. Now that looks like a building to me, but I'm going to talk in another video about how they communicate using something called quorum sensing. So but then the next step of biofilm formation is actually once a biofilm has reached its peak size, it's going to allow some of the cells to leave where they're going to go to a new site and form a new biofilm. So that is the basis of biofilm formation. I talked in the other video about how once they're in this biofilm, remember they're physically protected. They're way harder to kill with antibiotics up to a thousand times harder to kill. Some of the cells are really just kind of hanging out and slowed on their metabolism. Others are actively doing all sorts of things. But while they're in here, they're sharing nutrients. So where like the waste product of one cell becomes the food of another. So that's what allows the community to survive. That's how they get rid of their waste is basically, well, it's your waste, but it's your food. So let's work together. And then lastly, while they're in there, just imagine all the swapping. Think about each of these organisms having playing cards and they're swapping genetic material while they're in there. That's what's really terrifying is a relatively harmless organism can come into biofilm. When it leaves, it can be genetically modified, having traits that make it more virulent, more dangerous. It could be healthier, et cetera, et cetera. So, okay, that is biofilm formation and that is why it is important. Have a wonderful day. Be blessed.