Biodegradation and interaction of quinoline and glucose in dual substrates system

An indigenous mixed culture of microorganisms, isolated from a full-scale coal gasification wastewater treatment plant, was used in degrading quinoline in presence of glucose as an alternative carbon source. The results showed that biodegradation kinetics of both quinoline and glucose could be described by first-order reaction kinetics model. It was also found that the biodegradation rate of quinoline was accelerated by the presence of glucose, while glucose degradation was inhibited by the presence of quinoline. Both the biomass yield coefficient and specific growth rate were increased with the increasing of the glucose concentrations in the dual substrates system. A sum kinetics model was used to describe the relative effects of the two substrates on their individual uptakes. The interaction parameter values indicated that quinoline exhibits stronger inhibition on glucose degradation. But for glucose, its effect on quinoline utilization was stimulative. Furthermore, the stimulation was positively correlated with the concentration of glucose in the system.