A microorganism for the selective production of a specific component of avermectin and method for the selective preparation.

摘要

NEW MATERIAL:A microorganism selectively producing a specific component of avermectin (accumulating only (a)-component thereof) efficiently intaking isoleucine or keto acid corresponding thereto (3-methyl-2-oxovaleric acid) into avermectin skeleton and steeply reducing intaking valine or keto acid corresponding thereto (2-oxoisovaleric acid) into avermectin skeleton. USE:Used for production of avermectin as an antibiotic of anthelminthic. PREPARATION:For instance, a strain belonging to Streptomyces and accumulating only a-component of avermectin with efficiently intaking isoleucine or keto acid corresponding thereto into avermectin skeleton and steeply reducing intaking valine or keto acid corresponding thereto into avermectin skeleton is made to defect avermectin B O-methyl transferase activity by gene manipulation to afford Streptomyces avermitilis K2033 (FERM BP-2733) as a microorganism selectively producing a specific component of avermectin.