BIODEGRADATION OF SYNTHETIC PYRETHROID DIP INSECTICIDES: A THREE YEAR STUDY

摘要

Synthetic pyrethroid (SP)-degrading bacteria were isolated from soil previously exposed to SP sheep dips and identified as a Pseudomonas and a Serratia species. The Ps. Sp. Grew best in the lower temperatures whereas the Ser. Sp. Grew better at the warmer temperatures. Biodegradation rates were less affected by the culture temperature. Studies into the metabolism of the isolates showed that both organisms grew best and degraded the most SP in the mineral and sucrose cultures. However the limiting factors were different depending on the organism, with the Ps sp. Limited by the lack of minerals whereas the Ser. Sp. Was limited by the carbon source availability. With environmental samples it was found that the isolated organisms were significantly better at removing the SP from used sheep dip, but only by a few percent in comparison to the control.