Enhanced Degradation of Residual Cadusafos in Soils by the Microbial Agent of Cadusafos-degrading Sphingobium sp. Cam5-1

Abstract

Cadusafos, an organophosphorus insecticide, has been commonly used against various pests worldwide. Organophosphorus pesticides have shorter half-lives and lower toxicities than organochlorine pesticides. However, excessive use of Cadusafos can increase pest resistance and issues with acetylcholine biomagnification, potentially resulting in human toxicity. In this study, we investigated the effect of a Cadusafos-degrading micro-bial agent (CDMA) prepared using Sphingobium sp. Cam5-1, which was previously reported to effectively degrade residual Cadusafos in soil. Experiments were conducted under both controlled laboratory and greenhouse field conditions. Under laboratory conditions, CDMA (10 6 cfu/g soil application rate) decomposed 97% of Cadusafos in the soil in the untreated control after 21 days. Additionally, when CDMA (10 6 cfu/g soil) was mixed with quicklime, 99% of Cadusafos was decomposed within 3 days. Under greenhouse field conditions, the combined effect of CDMA (10 6 cfu/g soil) and quicklime was not observed. However, CDMA (10 6 cfu/g soil) application alone was capable of decompos-