Studies on Antibiotics Produced by Psychrophilic Microorganisms

Part I. Production of Antibiotics by a Psychrophile, Streptomyeces sp. No. 81

Abstract

A screening for antibacterial antibiotics was carried out with psychrophilic microorgan-isms. The most active microorganism, a soil actinomycete, was selected and characterized to be a facultative psychrophile, Streptomyces sp. No. 81. This strain was found to produce antibiotic (s) in the culture fluid only at low temperature cultivation below 20°C but not at moderate temperature. Mycelial growth at low temperature seemed to be indispensable for the antibiotic production. The antibiotic produced by Streptomyces sp. No. 81 was isolated and characterized. It appeared that the antibiotic had the selective toxicity against several Gram-positive bacteria. From the comparative studies with several known antibi-otics, the antibiotic appears to be a new compound derived from the new metabolic routes involving temperature-sensitive mechanisms.