LAUSR

In this study, a novel β-cypermethrin-degrading enzyme was isolated and purified by 32.8 fold from the extracellular cell-free filtrate of Pseudomonas aeruginosa GF31with the protein recovery of 26.6%. The molecular mass of the enzyme was determined to be 53 kDa. The optimum temperature for the activity was surprisingly 60 °C, and moreover, the purified enzyme showed a good pH stability, maintaining over 85% of its initial activity in the pH 5.0-9.0 range. Most of the common metal ions exhibited little influence on the activity except for Hg2+, Ag+, and Cu2+. After the complete gene sequence of the degrading enzyme was obtained by subcloning, sequence analyses as well as enzymatic properties demonstrated that the islolated enzyme should be an aminopeptidase. This is the first reported aminopeptidase for pyrethroid hydrolase, providing new potential enzyme resources for the degradation of this type of pesticide.