Title: Unveiling chlorpyrifos mineralizing and tomato plant-growth activities of Enterobacter sp. strain HSTU-ASh6 using biochemical tests, field experiments, genomics, and in silico analyses Haque MA, Hossain MS, Ahmad I, Akbor MA, Rahman A, Manir MS, Patel HM, Cho KM Ref: Front Microbiol, 13:1060554, 2022 : PubMed
The chlorpyrifos-mineralizing rice root endophyte Enterobacter sp. HSTU-ASh6 strain was identified, which enormously enhanced the growth of tomato plant under epiphytic conditions. The strain solubilizes phosphate and grew in nitrogen-free Jensen's medium. It secreted indole acetic acid (IAA; 4.8 mg/mL) and ACC deaminase (0.0076 microg/mL/h) and hydrolyzed chlorpyrifos phosphodiester bonds into 3,5,6-trichloro-2-pyridinol and diethyl methyl-monophosphate, which was confirmed by Gas Chromatography - Tandem Mass Spectrometry (GC-MS/MS) analysis. In vitro and in silico (ANI, DDH, housekeeping genes and whole genome phylogenetic tree, and genome comparison) analyses confirmed that the strain belonged to a new species of Enterobacter. The annotated genome of strain HSTU-ASh6 revealed a sets of nitrogen-fixing, siderophore, acdS, and IAA producing, stress tolerance, phosphate metabolizing, and pesticide-degrading genes. The 3D structure of 28 potential model proteins that can degrade pesticides was validated, and virtual screening using 105 different pesticides revealed that the proteins exhibit strong catalytic interaction with organophosphorus pesticides. Selected docked complexes such as alpha/beta hydrolase-crotoxyphos, carboxylesterase-coumaphos, alpha/beta hydrolase-cypermethrin, alpha/beta hydrolase-diazinon, and amidohydrolase-chlorpyrifos meet their catalytic triads in visualization, which showed stability in molecular dynamics simulation up to 100 ns. The foliar application of Enterobacter sp. strain HSTU-ASh6 on tomato plants significantly improved their growth and development at vegetative and reproductive stages in fields, resulting in fresh weight and dry weight was 1.8-2.0-fold and 1.3-1.6-fold higher in where urea application was cut by 70%, respectively. Therefore, the newly discovered chlorpyrifos-degrading species Enterobacter sp. HSTU-ASh6 could be used as a smart biofertilizer component for sustainable tomato cultivation.
Title: Mining of a novel esterase (est3S) gene from a cow rumen metagenomic library with organosphosphorus insecticides degrading capability: Catalytic insights by site directed mutations, docking, and molecular dynamic simulations Lee HY, Cho DY, Ahmad I, Patel HM, Kim MJ, Jung JG, Jeong EH, Haque MA, Cho KM Ref: Int J Biol Macromol, 190:441, 2021 : PubMed
A novel esterase (est3S) gene, 1026 bp in size, was cloned from a metagenomic library made of uncultured microorganisms from the contents of cow rumen. The esterolytic enzyme (Est3S) is composed of 342 amino acids and shows the highest identity with EstGK1 (71.7%) and EstZ3 (63.78%) esterases from the uncultured bacterium. The Est3S did not cluster in any up-to-date classes (I to XVIII) of esterase and lipase. Est3S protein molecular weight was determined to be 38 kDa by gel electrophoresis and showed optimum activity at pH 7.0 and 40 degreesC and is partially resistant to organic solvents. Est3S activity was enhanced by K(+), Na(+), Mg(2+), and Ca(2+) and its highest activity was observed toward the short-chain p-nitrophenyl esters. Additionally, Est3S can degrade chlorpyrifos (CP) and methyl parathion (70% to 80%) in an hour. A mutated Est3S (Ser132-Ala132) did not show any activity toward CP and ester substrates. Notably, the GHS132QG motif is superimposed with the homolog esterase and cutinase-like esterase. Therefore, Ser132 is the critical amino acid like other esterases. The Est3S is relatively stable with ester compounds, and the methyl parathion complex was confirmed by molecular dynamics simulation. NOVELTY STATEMENT: A novel esterase gene (est3S) expressing esters and organophosphorus insecticide degradation traits was isolated from the uncultured bacterium in the contents of cow rumen. The Est3S protein did not cluster in any up-to-date classes (I to XVIII) of esterase/lipase proteins. Est3S was stable with the ligands up to 100 ns during the molecular dynamic simulations.
Title: Organophosphorus hydrolase (OpdB) of Lactobacillus brevis WCP902 from kimchi is able to degrade organophosphorus pesticides Islam SM, Math RK, Cho KM, Lim WJ, Hong SY, Kim JM, Yun MG, Cho JJ, Yun HD Ref: Journal of Agricultural and Food Chemistry, 58:5380, 2010 : PubMed
Lactobacillus brevis WCP902 that is capable of biodegrading chlorpyrifos was isolated from kimchi. The opdB gene cloned from this strain revealed 825 bp, encoding 274 aa, and an enzyme molecular weight of about 27 kDa. OpdB contains the same Gly-X-Ser-X-Gly motif found in most bacterial and eukaryotic esterase, lipase, and serine hydrolases, yet it is a novel member of the GDSVG family of esterolytic enzymes. Its conserved serine residue, Ser82, is significantly involved with enzyme activity that may have application for removing some pesticides. Optimum organophosphorus hydrolase (OpdB) activity appeared at pH 6.0 and 35 degrees C and during degradation of chlorpyrifos, coumaphos, diazinon, methylparathion, and parathion.
Organophosphates are esters of phosphoric acid and can be hydrolyzed and detoxified by carboxylesterase and phosphotriesterase. In this work esterase enzyme (Est5S) was expressed in yeast to demonstrate the organophosphorus hydrolytic activity from a metagenomic library of cow rumen bacteria. The esterase gene (est5S) is 1098 bp in length, encoding a protein of 366 amino acid residues with a molecular weight of 40 kDa. Est5S enzyme was successfully produced by Pichia pastoris at a high expression level of approximately 4.0 g L-1. With p-nitrophenol butyrate as the substrate, the optimal temperature and pH for enzyme activity were determined to be 40 C and pH 7.0, respectively. The esterase enzyme was tested for degradation of chlorpyrifos (CP). TLC results obtained inferred that CP could be degraded by esterase enzyme (Est5S) and HPLC results revealed that CP could be efficiently degraded up to 100 ppm. Cadusafos (CS), coumaphos (CM), diazinon (DZ) dyfonate (DF), ethoprophos (EP), fenamiphos (FM), methylparathion (MPT), and parathion (PT) were also degraded up to 68, 60, 80, 40, 45, 60, 95, and 100%, respectively, when used as a substrate with Est5S protein. The results highlight the potential use of this enzyme in the cleanup of contaminated insecticides.
Title: 8-hydroxydihydrochelerythrine and 8-hydroxydihydrosanguinarine with a potent acetylcholinesterase inhibitory activity from Chelidonium majus L Cho KM, Yoo ID, Kim WG Ref: Biol Pharm Bull, 29:2317, 2006 : PubMed
Ethanol extract of the aerial portion of Chelidonium majus L. inhibited acetylcholinesterase (AChE) activity without a significant inhibition of butyrylcholinesterase (BuChE). Using mass spectrometry and NMR studies, three active constituents were isolated and identified: 8-hydroxydihydrochelerythrine (1), 8-hydroxydihydrosanguinarine (2), and berberine (3). Compounds 1-3 showed potent inhibitory activity against AChE, with IC50 (microM) values of 0.61-1.85. Compound 1 exhibited competitive and selective inhibition for AChE.
Title: Isoterreulactone A, a novel meroterpenoid with anti-acetylcholinesterase activity produced by Aspergillus terreus Yoo ID, Cho KM, Lee CK, Kim WG Ref: Bioorganic & Medicinal Chemistry Lett, 15:353, 2005 : PubMed
A new seven-membered lactone type meroterpenoid, isoterreulactone A, was isolated from the solid state fermentation of Aspergillus terreus and its structure was established by various spectral analysis. Isoterreulactone A inhibited acetylcholinesterase with an IC(50) value of 2.5 microM while did not inhibit butyrylcholinesterase even at 500 microM.
Title: Terreulactones A, B, C, and D: novel acetylcholinesterase inhibitors produced by Aspergillus terreus. I. Taxonomy, fermentation, isolation and biological activities Cho KM, Kim WG, Lee CK, Yoo ID Ref: J Antibiot (Tokyo), 56:344, 2003 : PubMed
In the course of screening for selective inhibitors of acetylcholinesterase from the microbial metabolites, four new meroterpenoid compounds, terreulactones A, B, C and D were isolated from solid state fermentation of Aspergillus terreus Fb000501. They showed potent inhibitory activities against acetylcholinesterase with IC50 values in range of 0.06 to approximately 0.42 microM. In addition, they exhibited more than 500 to approximately 3000 times selectivity for acetylcholinesterase compared with butyrylcholinesterase.
Title: Terreulactones A, B, C, and D: novel acetylcholinesterase inhibitors produced by Aspergillus terreus. II. Physico-chemical properties and structure determination Kim WG, Cho KM, Lee CK, Yoo ID Ref: J Antibiot (Tokyo), 56:351, 2003 : PubMed
Terreulactones A, B, C, and D, new meroterpenoid compounds with potent anti-acetylcholinesterase activity, were determined to be mixed polyketides-terpenoid structures by spectroscopic studies.
