streptomyces noursei streptomyces noursei streptomyces noursei is a bacterium species in the genus streptomyces. streptomyces noursei scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: streptomycetales family: streptomycetaceae genus: streptomyces species: s. noursei binomial name streptomyces nourseibrown et al. 1953 uses nystatin is a polyene antifungal medication isolated from s. noursei.