Streptomyces hayashii is a species of aerobic Gram-positive actinomycete. It was recently discovered and characterized in Brazil, along with Streptomyces hilarionis, where it has been associated with common scab, a disease that causes significant damage to potato crops worldwide. The type strain is IBSBF 2953<sup>T</sup>(other culture collections: CBMAI 2675<sup>T</sup>=ICMP 24301<sup>T</sup>=MUM 22.68<sup>T</sup>).