How can induced laboratory-induced mutations be used to obtain traits that humans need in microorganisms?

A striking example of the use of chemical mutagens is the creation of polyploid plant varieties. People always tried to breed those plants that had especially large fruits or yielded a large crop. In many cases, polyploids possess such properties. As it turned out, many cultivated plants belong to them: wheat, oats, potatoes, sugarcane, plums, cherries, etc. Chemical mutagens made it possible to obtain polyploids artificially. So, for example, V.V.Sakharov received tetraploid buckwheat, a high-yielding variety with large seeds.