The isolation and some properties of an enzyme system which catalyzes the degradation of β-nitropropionic acid

Abstract

An enzyme system, found in extracts of Penicillium atrovenetum, catalyzes the degradation of β-nitropropionic acid to nitrite, nitrate, and as yet unidentified carbon compounds. This thermolabile enzyme system requires oxygen for both nitrite and nitrate formation, and it appears to be specific for β-nitropropionic acid as a substrate. Nitrite formation is inhibited by reduced pyridine nucleotides, high concentrations (10 m m) of ferrous or ferric ions, and (1.0 m m) azide. Nitrate formation is inhibited by NADP, low concentrations (1.0 m m) of ferrous ions, and low concentrations (0.01 m m) azide. The evidence indicates that more than one enzyme is involved in the degradation, and that this system may be responsible for the production of nitrite and nitrate by growing cultures of P. atrovenetum.