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Journal ArticleDOI: 10.1016/J.CHEMOSPHERE.2021.130156

Fipronil degradation kinetics and resource recovery potential of Bacillus sp. strain FA4 isolated from a contaminated agricultural field in Uttarakhand, India

04 Mar 2021-Chemosphere (Pergamon)-Vol. 276, pp 130156-130156
Abstract: This study investigates the potential role of Bacillus sp. FA4 for the bioremediation of fipronil in a contaminated environment and resource recovery from natural sites. The degradation parameters for fipronil were optimized using response surface methodology (RSM): pH - 7.0, temperature - 32 °C, inocula - 6.0 × 108 CFU mL−1, and fipronil concentration - 50 mg L−1. Degradation of fipronil was confirmed in the mineral salt medium (MSM), soil, immobilized agar discs, and sodium alginate beads. The significant reduction of the half-life of fipronil suggested that the strain FA4 could be used for the treatment of large-scale fipronil degradation from contaminated environments. The kinetic parameters, such as qmax, Ks, and Ki for fipronil degradation with strain FA4, were 0.698 day−1, 12.08 mg L−1, and 479.35 mg L−1, respectively. Immobilized FA4 cells with sodium alginate and agar disc beads showed enhanced degradation with reductions in half-life at 7.83 and 7.34 days, respectively. The biodegradation in soil further confirmed the degradation potential of strain FA4 with a half-life of 7.40 days as compared to the sterilized soil control’s 169.02 days. The application of the strain FA4 on fipronil degradation, under different in vitro conditions, showed that the strain could be used for bioremediation and resource recovery of contaminated wastewater and soil in natural contaminated sites.

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Topics: Fipronil (63%), Bioremediation (52%)

5 results found

Journal ArticleDOI: 10.1016/J.CHEMOSPHERE.2021.130500
Sandhya Mishra1, Shimei Pang1, Wenping Zhang1, Ziqiu Lin1  +2 moreInstitutions (1)
01 Sep 2021-Chemosphere
Abstract: Carbamate compounds are commonly applied in agricultural sectors as alternative options to the recalcitrant organochlorine pesticides due to their easier breakdown and less persistent nature However, the large-scale use of carbamates also leads to toxic environmental residues, causing severe toxicity in various living systems The toxic effects of carbamates are due to their inhibitor activity against the acetylchlolinesterase enzyme This enzyme is crucial for neurotransmission signaling in living beings Hence, from the environmental point of view, the elimination of carbamates is a worldwide concern and priority Microbial technology can be deliberated as a potential tool that can work efficiently and as an ecofriendly option for the dissipation of carbamate insecticides from contaminated environments by improving biodegradation processes via metabolic activities of microorganisms A variety of bacterial and fungal species have been isolated and characterized and are capable of degrading a broad range of carbamates in soil and water environments In addition, microbial carbamate hydrolase genes (mcd, cehA, cahA, cfdJ, and mcbA) were strongly implicated in the evolution of new metabolic functions and carbamate hydrolase enzymes However, the accurate localization and appropriate functions of carbamate hydrolase enzymes/genes are very limited To explore the information on the degradation routes of carbamates and promote the application of biodegradation, a study of molecular techniques is required to unlock insights regarding the degradation specific genes and enzymes Hence, this review discusses the deep understanding of carbamate degradation mechanisms with microbial strains, metabolic pathways, molecular mechanisms, and their genetic basis in degradation

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Topics: Carbamate (55%)

5 Citations

Open accessJournal ArticleDOI: 10.3390/IJMS22179242
Guo Yuxin1, Yaohua Huang1, Shimei Pang1, Tianhao Zhou1  +5 moreInstitutions (1)
Abstract: Tetramethrin is a pyrethroid insecticide that is commonly used worldwide. The toxicity of this insecticide into the living system is an important concern. In this study, a novel tetramethrin-degrading bacterial strain named A16 was isolated from the activated sludge and identified as Gordonia cholesterolivorans. Strain A16 exhibited superior tetramethrin degradation activity, and utilized tetramethrin as the sole carbon source for growth in a mineral salt medium (MSM). High-performance liquid chromatography (HPLC) analysis revealed that the A16 strain was able to completely degrade 25 mg·L-1 of tetramethrin after 9 days of incubation. Strain A16 effectively degraded tetramethrin at temperature 20-40 °C, pH 5-9, and initial tetramethrin 25-800 mg·L-1. The maximum specific degradation rate (qmax), half-saturation constant (Ks), and inhibition constant (Ki) were determined to be 0.4561 day-1, 7.3 mg·L-1, and 75.2 mg·L-1, respectively. The Box-Behnken design was used to optimize degradation conditions, and maximum degradation was observed at pH 8.5 and a temperature of 38 °C. Five intermediate metabolites were identified after analyzing the degradation products through gas chromatography-mass spectrometry (GC-MS), which suggested that tetramethrin could be degraded first by cleavage of its carboxylester bond, followed by degradation of the five-carbon ring and its subsequent metabolism. This is the first report of a metabolic pathway of tetramethrin in a microorganism. Furthermore, bioaugmentation of tetramethrin-contaminated soils (50 mg·kg-1) with strain A16 (1.0 × 107 cells g-1 of soil) significantly accelerated the degradation rate of tetramethrin, and 74.1% and 82.9% of tetramethrin was removed from sterile and non-sterile soils within 11 days, respectively. The strain A16 was also capable of efficiently degrading a broad spectrum of synthetic pyrethroids including D-cyphenothrin, chlorempenthrin, prallethrin, and allethrin, with a degradation efficiency of 68.3%, 60.7%, 91.6%, and 94.7%, respectively, after being cultured under the same conditions for 11 days. The results of the present study confirmed the bioremediation potential of strain A16 from a contaminated environment.

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Topics: Tetramethrin (75%)

2 Citations

Journal ArticleDOI: 10.1007/S00253-021-11605-3
Zhe Zhou1, Xiaozhen Wu1, Ziqiu Lin1, Shimei Pang1  +2 moreInstitutions (1)
Abstract: Fipronil is a broad-spectrum phenyl-pyrazole insecticide that is widely used in agriculture. However, in the environment, its residues are toxic to aquatic animals, crustaceans, bees, termites, rabbits, lizards, and humans, and it has been classified as a C carcinogen. Due to its residual environmental hazards, various effective approaches, such as adsorption, ozone oxidation, catalyst coupling, inorganic plasma degradation, and microbial degradation, have been developed. Biodegradation is deemed to be the most effective and environmentally friendly method, and several pure cultures of bacteria and fungi capable of degrading fipronil have been isolated and identified, including Streptomyces rochei, Paracoccus sp., Bacillus firmus, Bacillus thuringiensis, Bacillus spp., Stenotrophomonas acidaminiphila, and Aspergillus glaucus. The metabolic reactions of fipronil degradation appear to be the same in different bacteria and are mainly oxidation, reduction, photolysis, and hydrolysis. However, the enzymes and genes responsible for the degradation are somewhat different. The ligninolytic enzyme MnP, the cytochrome P450 enzyme, and esterase play key roles in different strains of bacteria and fungal. Many unanswered questions exist regarding the environmental fate and degradation mechanisms of this pesticide. The genes and enzymes responsible for biodegradation remain largely unexplained, and biomolecular techniques need to be applied in order to gain a comprehensive understanding of these issues. In this review, we summarize the literature on the degradation of fipronil, focusing on biodegradation pathways and identifying the main knowledge gaps that currently exist in order to inform future research. KEY POINTS: • Biodegradation is a powerful tool for the removal of fipronil. • Oxidation, reduction, photolysis, and hydrolysis play key roles in the degradation of fipronil. • Possible biochemical pathways of fipronil in the environment are described.

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Topics: Fipronil (59%), Microbial biodegradation (50%)

Open accessJournal ArticleDOI: 10.1016/J.JHAZMAT.2021.127841
Ziqiu Lin1, Shimei Pang1, Zhe Zhou1, Xiaozhen Wu1  +7 moreInstitutions (1)
Abstract: The microbial degradation of acephate in pure cultures has been thoroughly explored, but synergistic metabolism at the community level has rarely been investigated. Here, we report a novel microbial consortium, ZQ01, capable of effectively degrading acephate and its toxic product methamidophos, which can use acephate as a source of carbon, phosphorus and nitrogen. The degradation conditions with consortium ZQ01 were optimized using response surface methodology at a temperature of 34.1°C, a pH of 8.9, and an inoculum size of 2.4×108 CFU·mL-1, with 89.5% of 200 mg·L-1 acephate degradation observed within 32 h. According to the main products methamidophos, acetamide and acetic acid, a novel degradation pathway for acephate was proposed to include hydrolysis and oxidation as the main pathways of acephate degradation. Moreover, the bioaugmentation of acephate-contaminated soils with consortium ZQ01 significantly enhanced the removal rate of acephate. The results of the present work demonstrate the potential of microbial consortium ZQ01 to degrade acephate in water and soil environments, with a different and complementary acephate degradation pathway.

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Topics: Acephate (59%), Methamidophos (57%), Microbial consortium (56%)

67 results found

Open accessJournal ArticleDOI: 10.1007/S11356-014-3332-7
Abstract: Systemic insecticides are applied to plants using a wide variety of methods, ranging from foliar sprays to seed treatments and soil drenches. Neonicotinoids and fipronil are among the most widely used pesticides in the world. Their popularity is largely due to their high toxicity to invertebrates, the ease and flexibility with which they can be applied, their long persistence, and their systemic nature, which ensures that they spread to all parts of the target crop. However, these properties also increase the probability of environmental contamination and exposure of nontarget organisms. Environmental contamination occurs via a number of routes including dust generated during drilling of dressed seeds, contamination and accumulation in arable soils and soil water, runoff into waterways, and uptake of pesticides by nontarget plants via their roots or dust deposition on leaves. Persistence in soils, waterways, and nontarget plants is variable but can be prolonged; for example, the half-lives of neonicotinoids in soils can exceed 1,000 days, so they can accumulate when used repeatedly. Similarly, they can persist in woody plants for periods exceeding 1 year. Breakdown results in toxic metabolites, though concentrations of these in the environment are rarely measured. Overall, there is strong evidence that soils, waterways, and plants in agricultural environments and neighboring areas are contaminated with variable levels of neonicotinoids or fipronil mixtures and their metabolites (soil, parts per billion (ppb)-parts per million (ppm) range; water, parts per trillion (ppt)-ppb range; and plants, ppb-ppm range). This provides multiple routes for chronic (and acute in some cases) exposure of nontarget animals. For example, pollinators are exposed through direct contact with dust during drilling; consumption of pollen, nectar, or guttation drops from seed-treated crops, water, and consumption of contaminated pollen and nectar from wild flowers and trees growing near-treated crops. Studies of food stores in honeybee colonies from across the globe demonstrate that colonies are routinely and chronically exposed to neonicotinoids, fipronil, and their metabolites (generally in the 1–100 ppb range), mixed with other pesticides some of which are known to act synergistically with neonicotinoids. Other nontarget organisms, particularly those inhabiting soils, aquatic habitats, or herbivorous insects feeding on noncrop plants in farmland, will also inevitably receive exposure, although data are generally lacking for these groups. We summarize the current state of knowledge regarding the environmental fate of these compounds by outlining what is known about the chemical properties of these compounds, and placing these properties in the context of modern agricultural practices.

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Topics: Pesticide (51%), Guttation (51%), Fipronil (51%) ... read more

686 Citations

Journal ArticleDOI: 10.1006/PEST.1993.1035
Abstract: The GABA-gated chloride channel is the proposed target for phenylpyrazole insecticides based on studies comparing four potent insecticidal compounds with two herbicidal but noninsecticidal analogs. The four insecticides used are 1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-1H-pyrazoles with the following heterocyclic substituents: 3-cyano-4-[(trifluoromethyl)sulfinyl]-5-amino (fipronil, 1), 4-[(trifluoromethyl)thiol (2), 4-[(trifluoromethyl)sulfinyl] (3), 4-[(trifluoromethyl)sulfonyl] (4). Pyrazole substituents of the two herbicidal analogs examined are 5-amino-4-nitro (5), 5-(2-chloropropanamide)-4-nitro (6). Piperonyl butoxide strongly antagonizes the toxicity of thioether 2 to houseflies, does not alter the potency of sulfoxide 3 and sulfone 4, and strongly synergizes sulfoxide 1, indicating the importance of oxidative activation and detoxification to insecticidal activity. Insecticides 1-4, but not herbicides 5 and 6, yield poisoning signs in house flies and mice similar or identical to those produced by trioxabicyclooctanes such as 1-[(4-ethynyl)phenyl]-4-n-propy-2,6,7-trioxabicyclo[2.2.2]octane (EBOB), which is known to block the γ-aminobutyric acid (GABA)-gated chloride channel. A dieldrin-resistant house fly strain with a low-affinity EBOB binding site is also tolerant to 1 and 2. The first four phenylpyrazoles are more potent than the latter two as inhibitors of [3H]EBOB binding with 50% inhibition levels of 2-20 nM in house fly head membranes and 1700-10,100 nM in mouse brain membranes. Compounds 1 and 2 are much more potent than 5 and 6 in inhibiting ivermectin-induced neurotransmitter release from cricket central nervous system synaptosomes. Compound 1 is also more effective than 2 and 5 at 20 μM in blocking GABA-dependent chloride uptake in mouse brain microvesicles; in this assay 6 is as effective as 1 although they act by different mechanisms in vivo in mice based on the symptomology. Neither 1 nor 2 inhibits [3H]avermectin binding in house fly head membranes. Phenylpyrazoles 1 and 2 block [3H]EBOB binding in house fly head membranes by reducing the Bmax but not the Kd, indicating that they are irreversible or poorly reversible inhibitors or act at a distinct but coupled binding site. The insecticidal phenylpyrazoles appear to block the GABA-gated chloride channel with higher potency for a site in house fly brain than in mouse brain, thereby providing useful selective toxicity. These findings are consistent with an earlier pharmacological investigation on the action of a structurally related phenyltriazole as a potent antagonist of GABA-activated chloride currents in insects.

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Topics: Trifluoromethyl (51%), Fipronil (51%), Chloride channel (50%)

432 Citations

Journal ArticleDOI: 10.1016/J.CHEMOSPHERE.2016.12.129
01 Apr 2017-Chemosphere
Abstract: Bioaugmentation, a green technology, is defined as the improvement of the degradative capacity of contaminated areas by introducing specific microorganisms, has emerged as the most advantageous method for cleaning-up soil contaminated with pesticides. The present review discusses the selection of pesticide-utilising microorganisms from various sources, their potential for the degradation of pesticides from different chemical classes in liquid media as well as soil-related case studies in a laboratory, a greenhouse and field conditions. The paper is focused on the microbial degradation of the most common pesticides that have been used for many years such as organochlorinated and organophosphorus pesticides, triazines, pyrethroids, carbamate, chloroacetamide, benzimidazole and derivatives of phenoxyacetic acid. Special attention is paid to bacterial strains from the genera Alcaligenes, Arthrobacter, Bacillus, Brucella, Burkholderia, Catellibacterium, Pichia, Pseudomonas, Rhodococcus, Serratia, Sphingomonas, Stenotrophomonas, Streptomyces and Verticillum, which have potential applications in the bioremediation of pesticide-contaminated soils using bioaugmentation technology. Since many factors strongly influence the success of bioaugmentation, selected abiotic and biotic factors such as pH, temperature, type of soil, pesticide concentration, content of water and organic matter, additional carbon and nitrogen sources, inoculum size, interactions between the introduced strains and autochthonous microorganisms as well as the survival of inoculants were presented.

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Topics: Bioaugmentation (60%), Bioremediation (57%), Pesticide (51%)

193 Citations

Journal ArticleDOI: 10.1016/J.JHAZMAT.2011.01.049
Shaohua Chen1, Meiying Hu1, Jingjing Liu1, Guohua Zhong1  +3 moreInstitutions (1)
Abstract: A newly isolated bacterium DG-S-01 from activated sludge utilized beta-cypermethrin (beta-CP) and its major metabolite 3-phenoxybenzoic acid (3-PBA) as sole carbon and energy source for growth in mineral salt medium (MSM). Based on the morphology, physio-biochemical characteristics, and 16S rDNA sequence analysis, DG-S-01 was identified as Ochrobactrum lupini. DG-S-01 effectively degraded beta-CP with total inocula biomass A(590 nm) = 0.1-0.8, at 20-40 °C, pH 5-9, initial beta-CP 50-400 mg L(-1) and metabolized to yield 3-PBA leading to complete degradation. Andrews equation was used to describe the special degradation rate at different initial concentrations. Degradation rate parameters q(max), K(s) and K(i) were determined to be 1.14 d(-1), 52.06 mg L(-1) and 142.80 mg L(-1), respectively. Maximum degradation was observed at 30 °C and pH 7.0. Degradation of beta-CP was accelerated when MSM was supplemented with glucose, beef extract and yeast extract. Studies on biodegradation in liquid medium showed that over 90% of the initial dose of beta-CP (50 mg L(-1)) was degraded under the optimal conditions within 5d. Moreover, the strain also degraded beta-cyfluthrin, fenpropathrin, cyhalothrin and deltamethrin. These results reveal that DG-S-01 may possess potential to be used in bioremediation of pyrethroid-contaminated environment.

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Topics: Energy source (52%)

122 Citations

Journal ArticleDOI: 10.1016/J.ECOENV.2012.04.004
Daisuke Hayasaka1, Tomoko Korenaga1, Kazutaka Suzuki1, F. Saito1  +2 moreInstitutions (2)
Abstract: Agricultural landscapes, including paddies, play an important role in maintaining biodiversity, but this biodiversity has been under the threat of toxic agro-chemicals. Our knowledge about how aquatic communities react to, and recover from, pesticides, particularly in relation to their residues, is deficient, despite the importance of such information for realistic environmental impact assessment of pesticides. The cumulative ecological impacts on aquatic paddy communities and their recovery processes after two successive annual applications of two systemic insecticides, imidacloprid and fipronil, were monitored between mid-May and mid-September each year. The abundance of benthic organisms during both years was significantly lower in both insecticide-treated fields than in the controls. Large-impacts of fipronil on aquatic arthropods were found after the two years. Growth of medaka fish, both adults and their juveniles, was affected by the application of the two insecticides. A Principal Response Curve analysis (PRC) showed the escalation and prolongation of changes in aquatic community composition by the successive annual treatments of each insecticide over two years. Residues of fipronil in soil, which are more persistent than those of imidacloprid, had a high level of impact on aquatic communities over time. For some taxonomic groups, particularly for water surface-dwelling and water-borne arthropods, the second annual treatment had far greater impacts than the initial treatment, indicating that impacts of these insecticides under normal use patterns cannot be accurately assessed during short-term monitoring studies, i.e., lasting less than one year. It is concluded that realistic prediction and assessment of pesticide effects at the community level should also include the long-term ecological risks of their residues whenever these persist in paddies over a year.

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Topics: Fipronil (52%)

111 Citations