Bioremediation Of Chlorpyrifos Research Articles

Modeling and optimization of chlorpyrifos and glyphosate biodegradation using RSM and ANN: Elucidating their degradation pathways by GC-MS based metabolomics

Ongoing and extensive use of pesticides negatively impact the environment and human health. Microbe-based remediation bears importance as it is an eco-friendly and cost-effective technique. The present study investigated chlorpyrifos (CHL) and glyphosate (GLY) degrading potential of Bacillus cereus AKAD 3–1, isolated from the soybean rhizosphere. Optimization and validation of different process variables were carried out by response surface methodology (RSM) and artificial neural network (ANN). Critical parameters which affect the degradation process are initial pesticide concentration, pH, and inoculum size. At optimum conditions, the bacterial strain demonstrated 94.52% and 83.58% removal of chlorpyrifos and glyphosate, respectively. Both Central-composite design (CCD-RSM) and ANN approaches proved to perform well in modeling and optimizing the growth conditions. The optimum ANN-GA model resulted in R2 ≥ 0.99 for chlorpyrifos and glyphosate, while in the case of RSM, the obtained R2 value was 0.96 and 0.95, respectively. Results indicated that the process variables significantly (p < 0.05) impact chlorpyrifos and glyphosate biodegradation. Moreover, the predicted RSM model had a “lack of fit p-value” of “0.8849” and “0.2502” for chlorpyrifos and glyphosate, respectively. GC-MS analysis revealed that the strain first converted chlorpyrifos into 3,5,6-trichloro pyridin-2-ol & O, O-diethyl O-hydrogen phosphorothiate. Later, these intermediate metabolites were broken and completely mineralized into non-toxic by-products. Similarly, glyphosate was first converted into 2-(methylamino) acetic acid and amino-oxyphosphonic acid, which were further mineralized without any toxic by-products. Taken together, the results of this study clarify the biodegradation pathways and highlights the promising potential of B. cereus AKAD 3–1 in the bioremediation of chlorpyrifos and glyphosate-polluted environments.

Study of formation of valuable organic products from bioremediation of chlorpyrifos by bacteria catalyzed by molybdenum and zinc salt

Experimental studies have been carried out to find the bioremediation activity of bacteria with molybdenum and zinc ions separately on the toxic insecticide, chlorpyrifos. Two bacterial strains, ZS20 (Enterobacter sp. strain TSNG) and E57 (Pseudomonas sp. strain GRTM) and three inorganic salts: ammonium-molybdate, sodium-molybdate, and zinc-nitrate, have been used for the degradation of toxic insecticide, chlorpyrifos. The metabolic products obtained are chelating organic acids, such as maleamic acid, ascorbic acid, salicylic acid, and other different derivatives of soluble-phosphate and phosphatase enzymes. They help for the better growth of plants. Ammonium-molybdate along with ZS20 strain is more active for the production of metabolic products and the growth of plants than the other combination. The liquid chromatography and mass spectrometry data of ZS20 and ammonium-molybdate salt portray complete degradation of chlorpyrifos into nontoxic valuable products. Hence, this combination can be used as good bioremediater as well as good biofertilizer. Results have been tabulated, shown graphically and discussed.

Biodegradation of Organophosphorous Pesticide: Chlorpyrifos

At the present time extensive varieties of pesticides are being used but the demand for organophosphorus pesticide is increasing globally to control insect. Chlorpyrifos is a broad spectrum, moderately toxic, chlorinated organophosphate insecticide that is synthetic in origin and is normally ester or thiol derivatives of phosphoric, phosphonic or phosphoramidic acids. The mode of action involves inhibiting acetyl cholinesterase leading to accumulation of acetylcholine causing neurotoxicity. It is being transported by circulation far away from site of application leading to pollution of environment. Due to its persistent in nature, it is not only severely detrimental to the target pests, but also causes toxicity in non-target organisms including humans. It is thus critically important to develop methods to eradicate these pollutants from the environment. Lately, research activities in this area have demonstrated that microorganisms are potential tool in decaying chlorpyrifos into less harmful and non-toxic metabolites through a process known as bioremediation. This article therefore aims at giving an overview of the present status of research and future prospects in bioremediation of chlorpyrifos.

Use of okara in the bioremediation of chlorpyrifos in soil: Effects on soil biochemical properties

The main objective of this manuscript was to study the bioremediation capacity of okara (a byproduct of soy milk production) in soils contaminated by organic xenobiotics. To this aim, and under controlled laboratory conditions, a soil was contaminated with chlorpyrifos insecticide at a dose of 5lha−1. Okara was added to this contaminated soil in two different manners: (1) pure okara (Op); and (2) a biostimulant/biofertilizer made from pure okara using the pH-stat technique. Several enzymatic activities (dehydrogenase, urease, β-glucosidase and phosphatase) and the evolution of the insecticide in soil were studied over an 80-day period. The results suggested that both forms of okara stimulated soil microorganisms and accelerated the degradation of chlorpyrifos in soil. It was, however, the biostimulant/biofertilizer that showed the greatest acceleration in insecticide degradation, possibly due to its higher content in low molecular weight (<300Da) peptides, easily available to soil microorganisms.

Effect of metal ions and petrochemicals on bioremediation of chlorpyrifos in aerobic sequencing batch bioreactor (ASBR).

Application of chlorpyrifos (CP) has increased its environmental concentration. Increasing CP concentration has increased chances of adverse health effects. Its removal from environment has attained researcher's attention. CP degrading bacterial strains were isolated from wastewater and agricultural soil. Finally, selected five bacterial strains were identified using 16S rRNA nucleotide sequence analysis as Pseudomonas kilonensis SRK1, Serratia marcescens SRK2, Bacillus pumilus SRK4, Achromobacter xylosoxidans SRK5, and Klebsiella sp. T13. Interaction studies among bacterial strains demonstrated possibility for development of five membered bacterial consortium. Biodegradation potential of bacterial consortium was investigated in the presence of petrochemicals and trace metals. About 98% CP removal was observed in sequencing batch reactors at inoculum level, 10%; pH, 7; CP concentration, 400mgL-1, and HRT, 48h. Experimental data has shown an excellent fit to first order growth model. Among all petrochemicals only toluene (in low concentration) has stimulatory effect on biodegradation of CP. Addition of petrochemicals (benzene, toluene, and xylene) in high concentration (100mgL-1) inhibited bacterial activity and decreased CP removal. At low concentration i.e., 1mgL-1 of inorganic contaminants (Cu, Hg, and Zn) >96% degradation was observed. Addition of Cu(II) in low concentration has stimulated CP removal efficiency. Hg(II) in all concentrations has strongly inhibited biodegradation rate except at 1mgL-1. In simulated pesticide, wastewater CP removal efficiency decreased to 77.5%. Outcomes of study showed that both type and concentration of petrochemicals and trace metals influenced biodegradation of CP.

Monitoring of organophosphorus pesticides and remediation technologies of the frequently detected compound (chlorpyrifos) in drinking water

Abstract Studies on the currently used organophosphorus insecticides with respect to their environmental levels and effective remediation technologies for their residues in water have been considered as a source of major concern. This study was carried out to monitor the presence of organophosphorus in drinking water plants (Kafr-El-Shiekh, Ebshan, Elhamoul, Mehalt Aboali, Fowa, Balteem and Metobess) in Kafr-El-Shiekh Governorate, Egypt. Furthermore, it was carried out to evaluate the efficiency of different remediation technologies (advanced oxidation processes and bioremediation) for removing chlorpyrifos in drinking water. The results showed the presence of several organophosphorus pesticides in water sampling sites. Chlorpyrifos was detected with high frequency relative to other compounds in drinking water. Nano photo-Fenton like reagent (Fe2O3(nano)/H2O2/UV) was the most effective treatment for chlorpyrifos removal in drinking water followed by ZnO(nano)/H2O2/UV, Fe3+/H2O2/UV and ZnO/H2O2/ UV, respectively. Bioremediation of chlorpyrifos by effective microorganisms (EMs) removed 100% of the chlorpyrifos initial concentration after 23 days of treatment. There is no remaining toxicity in chlorpyrifos contaminated-water after remediation on treated rats with respect to cholinesterase activity and histological changes in kidney and liver relative to control. Advanced oxidation processes especially with nanomaterials and bioremediation with effective microorganisms can be regarded as safe and effective remediation technologies for chlorpyrifos in drinking water.

Efficacy of Ganoderma sp. JAS4 in bioremediation of chlorpyrifos and its hydrolyzing metabolite TCP from agricultural soil

A novel fungal strain JAS4 was isolated from agricultural soil and was found to be highly effective in degrading chlorpyrifos and its major degradation product 3,5,6-trichloro-2-pyridinol (TCP). The molecular characterization based on 18S rRNA sequence analysis, revealed strain JAS4 as Ganoderma sp. which could able to degrade chlorpyrifos and its metabolite in an aqueous medium with rate constant of 0.8460 day(-1), following first order rate kinetics, and the time in which the initial insecticide concentration was reduced by 50% (DT(50)) was 0.81 days. Studies on biodegradation in soil with nutrients showed that JAS4 strain exhibited efficient degradation of insecticide with a rate constant of 0.9 day(-1), and DT(50) was 0.73 day. In contrast, degradation of insecticide in soil without nutrients was characterized by a rate constant of 0.7576 day(-1) and the DT(50) was 0.91 day.