Attempts to show Inhibition of Nitroreductase by Aureomycin in Cell-free Extracts and Isolation of an Aureomycin-resistant Nocardia V.

Abstract

Saz and Marmur¹ and Saz and Slie² have reported that the nitro-reductase system in a strain of Escherichia coli is sensitive to aureomycin. Saz, Brownell and Slie³ isolated a mutant of the organism which was resistant to the antibiotic and found that the nitro-reductase system of the mutant was also resistant to high concentrations of the drug. Now an investigation has been made of the sensitivity to aureomycin of the nitro-reductase enzyme system in Nocardia V.⁴. The growth of Nocardia is inhibited by concentrations of aureomycin as low as 1 µgm./ml. The cell-free nitro-reductase system isolated from the organism was not, however, sensitive to inhibition by aureomycin whether reduced diphosphopyridine nucleotide or diphosphopyridine nucleotide plus dehydrogenase substrate was used as hydrogen donor.