It’s an interesting device. It reminds me of fermentors which are used to ferment alchohol. They use yeast and bacteria to do the process of fermentation.
I don’t know exactly how the process works but I’d assume that the bacteria or yeast grow too in the process of creating fermentation. In fermentation however you don’t have controlled growth of microorganisms, so the chemostat is very unique.
I can imagine that they can use something like this in industrial science to grow certain organisms with useful properties, such as the ability to “eat” oil slicks or chemical spills.
Scientists could figure out exactly how many organisms they need for the ecological spill and grow only that amount, then release it into the ocean.