Yeasts are pretty cool little creatures.
They can kill you or work for you. My experimentation has focused on the useful Yeasts that convert sugars and starches into carbon dioxide or ethyl alcohol. When I get half a day free I enjoy baking bread. I have a bread machine, but mechanization takes the fun out of beating a wad of wet powdered wheat into a soft, fragrant, loaf of food. One of the things that I enjoy most about baking is when my kids come up and watch.