Abstract: The productive strain(Amycolatopsis mediterranei) produces a substance for inactivating self-product (Rif SV) in the course of Rif SV-biosynthesis.The experiments demonstrate that it is a protein consisting of 14 kinds of common amino acids including Gin, Asp,Lys, Val and so on.Its molecular weight (MW) is approximately 2.5×10⁴D and its isoelectric point (PI) is 5.7-6.1.After heated at 100℃ for 10 min,its activity is disappeared.The optimum PH range for reacting on Rif SV is 7.4-8.6 and the optimum temperature is 29℃.It is preliminarily identified as a enzyme (temporarily designated as Rifamycin SV-inactivation enzyme).

Key words: Amycolatopsis mediterranei, Rifamycin SV, Rifamycin SV-inactivation enzyme, Antibiotic enzyme