STREPTOMYCES AVERMITILIS MUTANT HAVING MODIFIED AVERMECTIN BC-5-O-METHYLTRANSFERASE GENE

摘要

PURPOSE: A Streptomyces avermitilis mutant which has modified gene encoding avermectin BC-5-O-methyltransferase and its producing method are provided, thereby mass-producing avermectin B compounds. CONSTITUTION: A DNA fragment contains an antibiotic tolerant gene between avermectin BC-5-O-methyltransferase gene, in which the DNA fragment contains 1.4 kb DNA fragment encoding a restriction enzyme S of the avermectin BC-5-O-methyltransferase gene and 1.1 kb neomycin resistant gene. A knockout vector comprising the DNA fragment having the restriction map of figure 2 modifies the avermectin BC-5-O-methyltransferase gene, and produces Streptomyces avermitilis mutant M1 (KCTC 18023P) transformed therewith and having a modified avermectin BC-5-O-methyltransferase gene.