Microbial kinetics of Pseudomonas sp. straub DM1 during dichloromethane biodegradation.

The microbial kinetics of Pseudomonas sp. strain DM1 during dichloromethane biodegradation was studied by means of fed-batch culture technique. The growth of the bacteria and the consumption of the substrate were inhibited severely by the substrate CH2Cl2 and the product chloride at high concentrations. The optimal concentrations for reaction were CH2Cl2 1.2 mM and chloride less than 100mM. When the concentrations of CH2Cl2 and/or chloride were higher than their restricted values, the bacteria would die and autolyse, mu less than or equal to 0. A modified kinetic model was proposed which can fit the experimental data, and is better than other traditional models. It consists of two terms: the first is due to the reversible Monod-type complexion mechanism and the second is regarded as an irreversible inhibition effect of a toxic compound on the microbial metabolism.