In order to enhance the activity of pyrethroid degrading enzyme

error prone PCR technology was used to modify a novel esterase gene (est825) which was derived from marine sediment metagenomic library. A mutant enzyme EstM46 was cloned and characterized. The activity of EstM46 was 1.5-fold higher than wild type (Est825)

and the optimum temperature was 5 degrees higher than that of Est825. Furthermore

the mutant enzyme stayed stable up to 70 ℃

remaining 80% (50% with Est825) of its activity after incubated at 70 ℃ for 2 h. The hydrolysis rates of cyhalothrin

cypermethrin

sumicidin and deltamethrin were 92.21%

99.75%

93.21% and 89.48%

respectively. A broad-spectrum pyrethroid-degrading enzyme with higher hydrolytic activity and more thermostability will play a better role in practical biodegradation.