"Actinomyces nigrescens" Sveshnikova in Gauze et al. 1957 Dataset NCBI Taxonomy Classification phylum Actinomycetota class Actinomycetes order Kitasatosporales family Streptomycetaceae genus Streptomyces species Streptomyces nigrescens Name Homonyms Actinomyces nigrescens "Actinomyces nigrescens" Sveshnikova in Gauze et al. 1957