Mechanisms of Azo Reduction by StreptococcusfaecalisI. Optimization of Assay Conditions

Abstract

1. A new method for the assay of azo-reductase activity in Streptococcus faecalis and several other microbial species is reported. The assay is continuous and permits a more rapid and accurate determination of specific activity than previously reported assays. 2. Optimal cofactor concentrations, pH and temperature have been determined for Streptococcus faecalis azo-reductase. 3. A lag period is observed before reduction proceeds at a constant rate and is probably due to generation of required reduced cofactors. The lag time depends on enzyme activity and cofactor concentrations and this variable may have been overlooked in earlier assay procedures.