Abstract
Mass spectrometry confirmed that the entire denitrification system of Thiosphaera pantotropha is present under aerobic conditions. Acetate-dependent oxygen uptake is totally inhibited by 0.3mM cyanide. Nitrate reduction by cells grown with and without nitrate was inhibited by 10 and 15mM azide, respectively. The nitrous oxide reductase was totally inhibited by 1% acetylene or 0.125mM cyanide. This reductase was only temporarily inhibited by 10mM azide. Frozen/thawed cell suspensions of T. pantotropha produced, under anaerobic conditions, only nitric oxide. The effects of various inhibitors on T. pantotropha are summarized and considered in relation to their effect on other denitrifiers.
