Aerobic cometabolism of trichloromethane by a butane-growing pure culture in continuous-flow biofilm reactors fed with pulsed injections of electron donor and acceptor

This work focuses on chloroform (CF) cometabolism by a butane-grown aerobic pure culture (Rhodococcus aetherovorans BCP1) in continuous-flow attached-growth bioreactors. The goals of this study were: i) to obtain preliminary information on the feasibility of CF biodegradation by BCP1 in biofilm reactors; and ii) to evaluate the applicability of the pulsed injection of growth substrate and oxygen to attached-growth bioreactors. Biofilm of BCP1 was formed on glass cylinders. The continuous supply of growth substrate (butane), which led to the attainment of the highest CF degradation rate, was compared with 4 schedules of butane and oxygen pulsed feeding. The best-performing pulsed injection schedule allowed the attainment of a 60% higher CF conversion (38%) and of a 4-fold increase of the mass of CF degraded per unit mass of butane consumed (0.17), in comparison with the continuous supply of substrate.