A novel organophosphate hydrolase from Arthrobacter sp. HM01: Characterization and applications. (April 2022)

• Record Type: Journal Article
• Authors: Mali, Himanshu; Shah, Chandni; Rudakiya, Darshan M.; Patel, Darshan H.; Trivedi, Ujjval; Subramanian, R.B.
• Is Part Of: Bioresource technology. Volume 349(2022)
• Publication Date: 2022-04
• Subjects: Pesticides -- Chemical warfare agents -- Bioremediation -- Site-directed mutagenesis -- Phosphotriesterase -- Organophosphorus; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.126870
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Organophosphates (OPs) pesticides are emerging environmental pollutants. A novel recombinant OPs hydrolase biocatalytic system (ropdH) was investigated. ropdH enzyme was functionally characterized to improve its catalytic properties. The active site of the ropdH enzyme was determined by site-directed mutagenesis. Several OPs pesticides were degraded by ropdH and a degradation pattern was proposed. Abstract: Bioremediation systems coupled to efficient microbial enzymes have emerged as an attractive approach for the in-situ removal of hazardous organophosphates (OPs) pesticides from the polluted environment. However, the role of engineered enzymes in OPs-degradation is rarely studied. In this study, the potential OPs-hydrolase ( opd H) gene ( Arthrobacter sp. HM01) was isolated, cloned, expressed, and purified. The recombinant organophosphate hydrolase (ropdH) was ∼29 kDa; which catalyzed a broad-range of OPs-pesticides in organic-solvent (∼99 % in 30 min), and was found to increase the catalytic efficiency by 10-folds over the native enzyme ( k cat / K m : 10 7 M −1 s −1 ). The degraded metabolites were analyzed using HPLC/GCMS. Through site-directed mutagenesis, it was confirmed that, conserved metal-bridged residue (Lys-127), plays a crucial role in OPs-degradation, which shows ∼18-folds decline in OPs-degradation. Furthermore, the catalytic activity and its stability has been enhanced by >2.0-fold through biochemical optimization. Thus, the study suggests that ropdH has all the required properties for OPs bioremediation.