Journal
MICROBIAL CELL FACTORIES
Volume 16, Issue -, Pages -Publisher
BIOMED CENTRAL LTD
DOI: 10.1186/s12934-017-0767-9
Keywords
Pyrethroid; Esterase; Immobilization; Reusability; Bioremediation; Vegetables
Categories
Funding
- National Natural Science Foundation of China [31400680]
- School Research Fund [2017xkj007]
- Early Research Training Program from Anhui Medical University [2013-ZQKY-09]
- Open Project from Anhui Province Biomass Clean Energy Key Laboratory
- Science and Technology Plan Project of Guangdong Province [2013B010404044, 2017A010105011]
- Education Project of Guangdong Province [2013KJCX0107, 2016KTSCX067]
- Guangdong Climbing Plans [pdjh2017b0262]
Ask authors/readers for more resources
Background: Pyrethroids are potentially harmful to living organisms and ecosystems. Thus, concerns have been raised about pyrethroid residues and their persistence in agricultural products. To date, although several pyrethroid-hydrolyzing enzymes have been cloned, very few reports are available on pyrethroid-hydrolyzing enzymes with cold adaptation, high hydrolytic activity and good reusability, indispensable properties in practical bioremediation of pyrethroid-contaminated vegetables. Results: Here, a novel gene (est684) encoding pyrethroid-hydrolyzing esterase was isolated from the Mao-tofu metagenome for the first time. Est684 encoded a protein of 227 amino acids and was expressed in Escherichia coli BL21 (DE3) in soluble form. The optimum temperature was 18 degrees C. It maintained 46.1% of activity at 0 degrees C and over 50% of its maximal activity at 4-35 degrees C. With the goal of enhancing stability and recycling biocatalysts, we used mesoporous silica SBA-15 as a nanometer carrier for the efficient immobilization of Est684 by the absorption method. The best conditions were an esterase-to-silica ratio of 0.96 mg/g (w/w) and an adsorption time of 30 min at 10 degrees C. Under these conditions, the recovery of enzyme activity was 81.3%. A large improvement in the thermostability of Est684 was achieved. The half-life (T-1/2) of the immobilized enzyme at 35 degrees C was 6 h, 4 times longer than the soluble enzyme. Interestingly, the immobilized Est684 had less loss in enzyme activity up to 12 consecutive cycles, and it retained nearly 54% of its activity after 28 cycles, indicating excellent operational stability. Another noteworthy characteristic was its high catalytic activity. It efficiently hydrolyzed cyhalothrin, cypermethrin, and fenvalreate in pyrethroid-contaminated cucumber within 5 min, reaching over 85% degradation efficiency after four cycles. Conclusions: A novel cold-adapted pyrethroid-hydrolyzing esterase was screened from the Mao-tofu metagenome. This report is the first on immobilizing pyrethroid-hydrolyzing enzyme on mesoporous silica. The immobilized enzyme with high hydrolytic activity and outstanding reusability has a remarkable potential for bioremediation of pyrethroid-contaminated vegetables, and it is proposed as an industrial enzyme.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available