Expression, Characterization, Fermentation, Immobilization, and Application of a Novel Esterase Est804 From Metagenomic Library in Pesticide Degradation

Abstract

Esterase, as a type of powerful catabolic enzyme for the degradation of pyrethroid pesticides (PYRs), appears promising in improving the quality of crops and the environment contaminated by pesticide residues. The purpose of this research is to provide a detailed introduction to the enzymatic properties, optimal production and immobilization conditions, and the degradation ability of Est804 for PYRs. The study on enzymatic properties indicated that Est804 was an alkaline esterase with an optimal pH of 8.0 and a broad optimal temperature in the range of 35−50°C. The optimal activity of free Est804 was calculated to be 112.812 U, and the specific enzyme activity was 48.97 U/mg. The kinetic parameters of Est804 were Km = 0.613 mM, kcat = 12,371 s–1, and Vm = 0.095 mM/min. The results of the fermentative optimization demonstrated that the optimal conditions included 1.5% of inoculation amount, 30 mL of liquid volume, 28°C of the fermentation temperature, and 18 h of the fermentation time. The optimal medium consists of 15.87 g of yeast powder, 8.00 g of glycerol, and 9.57 g of tryptone in 1 L of liquid. The optimized enzyme activity was 1.68-fold higher than that before optimization. Immobilized Est804 exhibited the highest activity under the optimum preparation conditions, including 0.35 g of chitosan dosage, 0.4 mL of an enzyme, and 4 h at 40°C for adsorption. The degradation rates of Cypermethrin (CYP), fenpropathrin (FE), and lambda-cyhalothrin (LCT) by Est804 within 30 min were 77.35%, 84.73%, and 74.16%, respectively. The present study indicated that Est804 possesses great potential for the treatment of pesticide residues on crops and environmental remediation, conducive to the development of SGNH family esterase against pyrethroid accumulation.

Expression, characterization, and immobilization of a novel SGNH esterase Est882 and its potential for pyrethroid degradation

“…The reaction mixture was saturated with sodium chloride and extracted with an equal volume of N-hexane. One microliter of the reaction liquid was used for quantitative analysis by gas chromatograph (GC; Agilent7890B, USA) on HP-5MS column ( Chen et al, 2022 ). The conditions of GC analysis were as follows: the split ratio of 5:1; the injection volume of 1.0 μl; the injection temperature of 260°C; the column flow of 1.0 ml/min.…”

“…The conditions of GC analysis were as follows: the split ratio of 5:1; the injection volume of 1.0 μl; the injection temperature of 260°C; the column flow of 1.0 ml/min. Besides, the carrier gas was high purity nitrogen with a total flow rate of 9 ml/min ( Chen et al, 2022 ). The concentration of pyrethrin was calculated according to the peak area.…”

Pesticides Toxicity, Removal and Detoxification in Plants: A Review

“…Notably, microorganisms secrete hydrolytic enzymes to participate in pesticide degradation. For example, the Est804 enzyme achieved degradation rates of 77.35%, 84.73% and 74.16% for CYP, fenpropathrin (FE) and lambdacyhalothrin (LCT), respectively, within 30 min [69]. IMD, as an important insecticide, has become a new pollutant.…”