Isolation and characterization of organophosphorus phosphatases from Bacillus thuringiensis MB497 capable of degrading Chlorpyrifos, Triazophos and Dimethoate

Abstract

In the current investigation, bacterial strain Bacillus thuringiensis MB497 was examined for production of intracellular and extracellular organophosphorus phosphatase (OPP) enzymes. This strain produced significant amount of extracellular acidic and alkaline phosphatases. Production of neutral phosphatase was negligible. Production of OPP was generally highest at pH 11 and at 45-50 C. However, activity and stability of OPP was highest at 37 C and reduced at higher temperatures. OPP production was decreased after 48 h of incubation. Largely, OPP activity was inhibited by SDS and EDTA and significantly enhanced by metals (Zn þþ , Cu þþ and Cd þþ ). Both acidic and alkaline OPPs were capable of bio-precipitation of selected metals (Ni, Mn, Cr and Cd) up to 86-100%. When used against 50 mg/l of three OP pesticides (Chlorpyrifos, Triazophos, and Dimethoate), 81-94.6% degradation of pesticides was observed by alkaline OPP, while acidic OPP showed less degradation (61-70.5%) within 30 min of incubation.

Identification of chlorpyrifos-degrading microorganisms in farmland soils via cultivation-independent and -dependent approaches

“…Bacillus, a kind of Gram-positive bacterium that is oen used in bioremediation, is also capable of promoting plant growth and reducing hormones against antimicrobial compounds and volatile compounds. 26,27 Pseudomonas has been widely studied for the degradation of multiple pollutants, including nitrophenols, aromatic compounds and pesticides, e.g., carbamates, organochlorines and organophosphates. Pseudomonas nitroreducens strain AR-3 was the fastest degrader among Pseudomonads, which could degrade 97% of CPF within 8 h. 28 Other microorganisms enriched in MFC_CPF, including Citrobacter, Exiguobacterium, Azoarcus, Geobacter and Ramlibacter, are possibly related to the degradation or mineralization of multiple pollutants.…”

“…Bacillus , a kind of Gram-positive bacterium that is often used in bioremediation, is also capable of promoting plant growth and reducing hormones against antimicrobial compounds and volatile compounds. 26,27 Pseudomonas has been widely studied for the degradation of multiple pollutants, including nitrophenols, aromatic compounds and pesticides, e.g. , carbamates, organochlorines and organophosphates.…”

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“…The presence of available P by phosphate solubilizing Bacillus may contribute the P supply for ATP formation. Both Bacillus species in this experiment produced extracellular phosphatase (Hindersah et al, 2020b) as a prominent mechanism to solubilize the organic P in growth substrate (Guang et al, 2008;Ambreen et al,2020).…”

Inhibitory properties of polyphenols in Malus “Winter Red” crabapple fruit on α‐glucosidase and α‐amylase using improved methods

“…The use of pNPG as a substrate for α-glucosidase activity assays began in the 1950s and mainly focused on yeast glycosidases (Hall et al, 1962;Robertson & Halvorson, 1957). Later, this method was adapted to measure the inhibitory properties of polyphenols on αglucosidase in vitro because the method is convenient and the pNG that is a product of enzymatic decomposition of pNPG has a large range of linear relationship between the concentration and absorbances (Ambreen et al, 2020). But the interference of polyphenols had seldom been considered.…”