streptomyces verticillus streptomyces verticillus streptomyces verticillus is a species of gram-positive bacteria in the genus streptomyces. 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. streptomyces verticillus scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: streptomycetales family: streptomycetaceae genus: streptomyces species: s. verticillus binomial name streptomyces verticillus