The concept of using chemicals made by bacteria or fungi to treat diseases is hardly new. Penicillin came from the bread mold Penicillium and streptomycin came from bacteria known as actinomycetes, to name two well-known examples. But looking for medically valuable substances in the ocean is relatively new—and very promising. Each kind of marine bacteria produces possibly hundreds of small molecules called secondary metabolites, most of which have never been studied before.
