Kinetics of aerobic growth of a denitrifying bacterium, Pseudomonas denitrificans, in the presence of nitrates and/or nitrites

Batch experiments have been employed to develop a mathematical model for the aerobic growth of a known denitrifier, Pseudomonas denitrificans, in the presence or absence of nitrate and/or nitrite. Specially designed batch experiments were used in order to evaluate the modelʹs kinetic parameters. The aerobic growth kinetics, could be very well described by using double Monod expressions for the limiting substrates (organic carbon and oxygen). The proposed model is capable of describing accurately cellular growth, organic carbon utilization and oxygen transfer and utilization rates. The presence of nitrites and/or nitrates in the culture medium for the aerobic growth of P. denitrificans caused an intense decrease of the cell growth rate and the growth yield. These effects were accounted for in the kinetic model extending thus its validity for describing growth under aerobic conditions both in the absence and in the presence of various concentrations of nitrite and nitrate in the range of 0 to about 400 mg N/L.