Growth Kinetics of Attached Iron-Oxidizing Bacteria

Publisher Website
Google Scholar
Abstract
A model of growth and substrate utilization for ferrous-iron-oxidizing bacteria attached to the disks of a rotating biological contactor was developed and tested. The model describes attached bacterial growth as a saturation function in which the rate of substrate utilization is determined by a maximum substrate oxidation rate constant ( P ), a half-saturation constant ( K s ), and the concentration of substrate within the rotating biological contactor ( S 1 ). The maximum oxidation rate constant was proportional to flow rate, and the substrate concentration in the reactor varied with influent substrate concentration ( S 0 ). The model allowed the prediction of metabolic constants and included terms for both constant and growth-rate-dependent maintenance energies. Estimates for metabolic constants of the attached population of acidophilic, chemolithotrophic, iron-oxidizing bacteria limited by ferrous iron were: maximum specific growth rate (μ max ), 1.14 h −1 ; half-saturation constant ( K s ) for ferrous iron, 54.9 mg/liter; constant maintenance energy coefficient ( m 1 ), 0.154 h −1 ; growth-rate-dependent maintenance energy coefficient (m′), 0.07 h −1 ; maximum yield ( Y g ), 0.063 mg of organic nitrogen per mg of Fe(II) oxidized.