How and why are bacteria used in industry?

Bacteria are used in industry to produce enzymes and other proteins. Because they are prokaryotes and don't have a nucleus, every DNA plasmid that is taken up is translated. You just have to insert the plasmid that codes the protein you want to produce and the bacteria will make it. They also have a very rapid expansion phase and are easy to grow, making them perfect for mass production. They are used to produce drugs such as insulin and even detergents in washing up liquid.Imagine a big pot in which all these bacteria are growing. They are being constantly mixed by a big rotor so the nutrients are spread evenly. At the bottom of the pot is a tap where you can drain the excess liquid that contains all the debris from the dead cells. The enzyme you're looking for is part of this debris, so all you have to do now is to separate it from the rest and collect it.