Abstract
In taxonomic studies on two streptomyces, the strain MCRL-0357 which produces the antibiotic BD-12 was recognized to be a new species of streptomyces and named Streptomyces luteocolor nov. sp. The strain MCRL-0358 which produces antibiotic BY-81 was concluded to be a new variety of Streptomyces olivoreticuli ARAI et al. The production of both antibiotics were described.