Generic studies on the oxytetracycline producing organism, Streptomyces alboflavus

Abstract

The Actinomycete organism, Streptomyces alboflavus, produces the antibiotic oxytetracycline. Treatment with curing agents resulted in S. alboflavus losing the ability to produce oxytetracycline. However, the loss of oxytetracyc1ine production was reversible, and non-producing colonies regained the ability to produce oxytetracycline when the curing agent was removed. Therefore the loss of oxytetracyc1ine production was not due to the irreversible loss of genetic material specifying oxytetracycline production, but was possibly due to genetic instability. Two extrachromosomal DNA species were isolated from S. alboflavus, (SAP1 and SAP2). SAP1 was approximately 8 - 10 x 10â ¶ da1tons, and appeared to be linear and heterogenous. SAP2 was 20 - 25 x 10â ¶ daltons and appeared to be covalently closed circular. The functions of SAP1 and SAP2 are unknown, although transformation experiments with SAP1 suggested that it may play a role in the production of an antibiotic-like substance, possibly by acting as a promotor of the genes coding for the antibiotic-like substance.