Pyrene biodegradatin in aqueous solutions and soil slurries by Mycobacterium PYR-1 and enriched consortium

To better understand complex bioavailability issues, pyrene degradation was examined in aqueous and soil slurry solutions using pure Mycobacterium sp. PYR-1 and a microbial consortium. The intrinsic rates of the aqueous pyrene degradation were very similar, 1.3×10−9 μg pyrene/CFU-h for Mycobacterium sp. PYR-1 and 1.1×10−9 μg pyrene/CFU-h for the consortium. Rates were much lower with the soil-slurry experiments, ranging from 1.2×10−12 to 7.8×10−10 μg/CFU-h, depicting the strong negative effects of soils on bioavailability. Supernatants from the slurry experiments were found to increase the aqueous-phase pyrene solubility significantly. Pyrene solubility was increased from 120.5 to over 230 μg/l. However, the linear adsorption constants of pyrene on the soil were reduced.