In this video, we're going to begin our lesson on oxygen requirements for microbial growth. And so it turns out that all organisms that utilize chemical energy require what's known as a final electron acceptor for their electron transport chain. Now, later in our course in a different video, we'll talk a lot more about these final electron acceptors and electron transport chains. But for now, here in this video, you can just imagine that the final electron acceptor and electron transport chain are important for generating energy for the cell. Now, in many microbes, the final electron acceptor in this electron transport chain is going to be oxygen gas or O2.
And so organisms that utilize oxygen gas as the final electron acceptor are referred to as aerobes. And so aerobes are really just microbes that require oxygen gas to act as the final electron acceptor in the electron transport chain. And therefore, these aerobes are going to require oxygen to be abundant in order for them to grow, and so aerobes only grow where oxygen is abundant. We call these areas, these environments that have lots of oxygen, aerobic environments. And so aerobes require oxygen for growth, and therefore they grow only in aerobic environments where there's lots of oxygen.
Now, on the other hand, anaerobes are microbes that grow where little to no oxygen is present. And when little to no oxygen is present, we refer to these as anaerobic environments. And so if we take a look at our image down below, notice on the left-hand side over here we're focusing on aerobic environments. And so in aerobic environments, there is plenty of oxygen, and aerobes are capable of surviving in aerobic environments. And so here we're showing you an aerobe because notice he's saying, "I can't live without you," speaking to the oxygen gas.
And so aerobes require oxygen to be present. An example of that is Mycobacterium tuberculosis, which is a bacterium that causes tuberculosis, a lung condition. Now, on the right hand side over here, what we're focusing on is the anaerobic environment. The anaerobic environment is the opposite of the aerobic environment. Anaerobic environments do not have a lot of oxygen, and so aerobes are capable of surviving in anaerobic environments.
And so over here, what we have is an aerobe, and notice this one has a completely different opinion of oxygen. It's saying, "No, thank you. I do not need oxygen to grow." And so, an example of this, anaerobe, I'm sorry, is going to be Bacteroides fragilis, which is a bacterium that survives in the gastrointestinal tract of humans.
And so, this here concludes our brief introduction to oxygen requirements for microbial growth and how aerobes grow in aerobic environments with lots of oxygen and anaerobes grow in anaerobic environments with little to no oxygen. And so we'll be able to learn more about the oxygen requirements for microbial growth as we move forward in our lesson. So I'll see you all in our next video.