Azoreductase and Nitroreductase in Human Feces: Comparison of Methods to Measure Specific Activities in the Absence of Oxygen

We measured the specific activity of azoreductase and nitroreductase in eight fresh samples of human feces, using three ways to produce anaerobic assay conditions. A fourth, bench top aerobic assay was also run. Using Oxyrase to produce anaerobic conditions on the open bench gave a significantly higher level of azoreductase than did running the assay entirely in an anaerobic the glove box. Nitroreductase levels were similar in the two assays. Oxyrase and the glove box both gave significantly higher levels of each activity than did either the aerobic bench top or the Anaerobe Lab transfer system. The latter was no improvement over the aerobic, bench top assay. We conclude that Oxyrase is a technically competitive way to conduct anaerobic assays. Keywords: azoreductase, nitroreductase, anaerobe, colon, feces.