And penicillin is a classic "recognize what you have found" example, scientists prior to Alexander Fleming had noted and wrote up observations of molds killing

And penicillin is a classic "recognize what you have found" example, scientists prior to Alexander Fleming had noted and wrote up observations of molds killing cultured bacteria, but just treated that as a curiosity. He, at least, was actively looking for anti-bacterial agents after his experiences in WWI battlefield hospitals.