The biological reduction of N2O, a potent greenhouse gas, is crucial for environmental sustainability. We developed an automated system for continuous N2O monitoring in the gas phase of a flask containing an anaerobic bradyrhizobial culture, and then exami-ned the kinetic parameters of bacterial N2O reduction. The maximum reaction rate (Vmax) was approximately 61-fold higher for Bradyrhizobium ottawaense SG09 (1,471 nmol h-1 109 cells-1) than for B. diazoefficiens USDA110 (24 nmol h-1 109 cells-1). Our kinetics anal-ysis confirmed that SG09 maintained higher N2O-reducing activity than USDA110 even at the atmospheric concentration of N2O (0.34 ppm).
Itakura et al. (Thu,) studied this question.