The novel carboxylesterase gene (
est741) was cloned from
Geobacillus uzenensis. The optimal pH and temperature of Est
741 were 8.0 and 50 °C. Through site-directed mutation, the optimum temperature of the mutant M160K(Est
M160K) was increased from 50
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The novel carboxylesterase gene (
est741) was cloned from
Geobacillus uzenensis. The optimal pH and temperature of Est
741 were 8.0 and 50 °C. Through site-directed mutation, the optimum temperature of the mutant M160K(Est
M160K) was increased from 50 to 60 °C, and showed enhanced T
1/2 of 2.5 h at 70 °C in comparison to the wild type (1.3 h). Est
M160K was successfully expressed
Pichia pastoris and Est
M160K fermentation broth was directly immobilized on epoxy-functionalized supports via a one-pot strategy to obtain the immobilized enzyme lx-Est
M160K. Additionally, lx-Est
M160K showed enhanced T
1/2 of 36.8 h at 70 °C in comparison to free enzyme. lx-Est
M160K could degrade various pyrethroid pesticides. After 40 min reaction with 50 U of the lx-Est
M160K, the malathion removal was 95.8% with a malathion concentration of 20 mg/L. When 2.5 g lx-Est
M160K was added to the 10 mL column reactor with the concentration of bifenthrin was 500 mg/L and the transfer rate of the pump was 0.7 mL/min, the degradation rate of lx-Est
M160K to bifenthrin was 90.4%. lx-Est
M160K exhibited high operational stability and maintained 72% initial activity after ten batches of continuous reaction for bifenthrin pesticide biodegradation.
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