Biotransformation of heptachlor to hydroxychlordene by soil bacteria

Heptachlor is an organochlorine pesticide that can persist in the environment, resulting in environmental problem with chronic effects on human and animal health. The determination of heptachlor in soil samples from 9 agricultural areas in Karawang district, West-Java, Indonesia central of paddy field, found heptachlor residue in the ranges of 0.3-4.5 ng/g soil. From representative of these sampled areas and after repeated culturing in nutrient agar 5 morphologically different bacterial strains were isolated. Out of isolates, bacteria potentials was showed heptachlor degrading ability as indicated by protein increase when grown on Medium Mineral (MM) supplemented up to 0.2-2.0 μg/g. Growth of these isolates in MM+heptachlor 2.0 μg/g after 30 days indicated reductions of heptachlor until 3.99 ng/g. Based on GC analysis, showed the new peak in time (rt) 10.78 minute and consistence all of concentration was 1-hydroxychlordene. And, the morphological characteristics and 16S rDNA analysis, isolate B4 which showed the highest degradation ability was found to be 99% identical (1360/1362) to Raoultella ornithinolytica B4.