Biodehalogenation of low concentrations of 1,3-dichloropropanol by mono- and mixed cultures of bacteria

The degradation of low concentrations of 1,3-dichloro-2-propanol (1,3-DCP) and related halohydrins by whole cells and cell-free extracts of soil bacteria has been investigated. Three bacteria (strains A1, A2, A4), isolated from the same soil sample, were distinguished on the basis of cell morphology, growth kinetics and haloalcohol dehalogenase profiles. Strain A1, probably an Agrobacterium sp., dehalogenated 1,3-DCP with the highest specific activity (0.33 U mg protein-1) and also had the highest affinity for 1,3-DCP (Km, 0.1 mM). Non-growing cells of this bacterium dehalogenated low concentrations of 1,3-DCP with a first-order rate constant (kl) of 1.13 h-1. The presence of a non-dehalogenating bacterium, strain G1 (tentatively identified as Pseudomonas mesophilius), did not enhance the dehalogenation rate of low 1,3-DCP concentrations. However, the mixed-species consortium of strains A1 and G1 had greater stability than the mono-species culture at DCP concentrations above 1.0 gl-1.