Streptomyces verticillus

Streptomyces verticillus is a species of Gram-positive bacteria in the Streptomyces genus. Whilst screening fermentation broths of this species for bioactivity in the early 1960s, Hamao Umezawa and colleagues at the Institute of Microbial Chemistry in Tokyo identified a family of glycopeptide antitumor antibiotics called the bleomycins. Examples of the bleomycins in clinical use include bleomycin A₂ (also known as bleomycin) and bleomycin A₅ (also known as pingyangmycin). Both are used to treat lymphomas (e.g. Hodgkin's lymphoma), head and neck cancer, and testicular cancer.