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Learn the toughest concepts covered in Microbiology with step-by-step video tutorials and practice problems by world-class tutors.

10. Dynamics of Microbial Growth

Growing a Pure Culture


Growing a Pure Culture

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in this video, we're going to begin our lesson on growing a pure culture. And so in a scientific lab or a microbiology lab, bacterial and our kale cells are generally isolated, grown and studied in what's known as a pure culture. And so a pure culture can be defined as a population of cells containing only one single species. And typically these pure cultures are grown starting from a single colony. Now, a colony is a scientific term that's used to describe a group of approximately one million cells or so, and colonies are going to be required to start up your culture. And these pure cultures are again typically grown in a lab. And so if we take a look at our image down below, over here, at this pure culture, notice that we're starting with just a single bacterial cell over here and this single bacterial cell will divide and replicate in order to create many more cells of the same exact species. And so we have a population of cells here, But this population of cells consists of just one single species. And because we have a lot of cells here, if we had about one million cells or so, we would have ourselves a colony of cells or a group of cells that are all the same species. And so this is an example of a pure culture because it is uh they're all it's a population of cells containing only one species. And so notice here that this old guy over here saying, look at all my Children. And these guys are saying, we form a colony together and all cells are going to be descended from a single cell in a pure culture. That is what allows for the population of cells to only contain one single species. Now there is another term here that might be important to keep in mind if you're in a microbiology lab and that is the term in Oculus. Um And so an inoculation is really just a colony of cells that are added to a culture medium in order to start a pure culture. And so if we were to take if we wanted to create a pure culture, what we would typically do is start with a colony of cells that are all of a single species. And then we would use that colony as an inoculation um to inoculate some other kind of culture medium and start a new pure culture. And so this year concludes our brief introduction to growing a pure culture and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.

A pure culture of bacteria is made of…


A bacterial culture grown in a _________________ will not continue to grow exponentially forever, but will stop once the limited nutrients have been consumed.