A comprehensive review on enzymatic degradation of the organophosphate pesticide malathion in the environment

Applications of Microbial Organophosphate-Degrading Enzymes to Detoxification of Organophosphorous Compounds for Medical Countermeasures against Poisoning and Environmental Remediation

Mining of organophosphorous (OPs)-degrading bacterial enzymes in collections of known bacterial strains and in natural biotopes are important research fields that lead to the isolation of novel OP-degrading enzymes. Then, implementation of strategies and methods of protein engineering and nanobiotechnology allow large-scale production of enzymes, displaying improved catalytic properties for medical uses and protection of the environment. For medical applications, the enzyme formulations must be stable in the bloodstream and upon storage and not susceptible to induce iatrogenic effects. This, in particular, includes the nanoencapsulation of bioscavengers of bacterial origin. In the application field of bioremediation, these enzymes play a crucial role in environmental cleanup by initiating the degradation of OPs, such as pesticides, in contaminated environments. In microbial cell configuration, these enzymes can break down chemical bonds of OPs and usually convert them into less toxic metabolites through a biotransformation process or contribute to their complete mineralization. In their purified state, they exhibit higher pollutant degradation efficiencies and the ability to operate under different environmental conditions. Thus, this review provides a clear overview of the current knowledge about applications of OP-reacting enzymes. It presents research works focusing on the use of these enzymes in various bioremediation strategies to mitigate environmental pollution and in medicine as alternative therapeutic means against OP poisoning.

Combined metabolomics and proteomics to reveal the mechanism of S. oneidensis MR-1 degradation malathion enhanced by FeO/C

Iron oxide @ biochar (FeO/C) promotes bacterial growth and facilitates electron transfer, thereby effectively promoting malathion degradation by Shewanella oneidensis MR-1 (S. oneidensis MR-1). This study elucidated the underlying mechanism of FeO/C-enhanced malathion degradation by S. oneidensis MR-1 through a combination of metabolomics and proteomics analysis. The kinetic fitting results from the degradation experiment indicated that 0.1 g/L FeO/C exerted the most significant enhancement effect on malathion degradation by S. oneidensis MR-1. Observations from Scanning Electron Microscopy and Laser Scanning Confocal Microscopy, along with physiological and biochemical analysis, showed that FeO/C enhanced the growth and oxidative response of S. oneidensis MR-1 under malathion stress. In addition, metabolomics and proteomics analysis revealed an increase in certain electron transfer related metabolites, such as coenzymes, and the upregulation of proteins, including coenzyme A, sdhD, and petC. Overall, spectroscopic analysis suggested that Fe2+, which was reduced from Fe3+ by S. oneidensis MR-1 in FeO/C, promoted electron transfer in S. oneidensis MR-1 to enhance the degradation of malathion. This study offers enhanced strategies for efficient removal of malathion contaminants.

Role of Lactic Acid Bacteria in Insecticide Residue Degradation

Lactic acid bacteria are gaining global attention, especially due to their role as a probiotic. They are increasingly being used as a flavoring agent and food preservative. Besides their role in food processing, lactic acid bacteria also have a significant role in degrading insecticide residues in the environment. This review paper highlights the importance of lactic acid bacteria in degrading insecticide residues of various types, such as organochlorines, organophosphorus, synthetic pyrethroids, neonicotinoids, and diamides. The paper discusses the mechanisms employed by lactic acid bacteria to degrade these insecticides, as well as their potential applications in bioremediation. The key enzymes produced by lactic acid bacteria, such as phosphatase and esterase, play a vital role in breaking down insecticide molecules. Furthermore, the paper discusses the challenges and future directions in this field. However, more research is needed to optimize the utilization of lactic acid bacteria in insecticide residue degradation and to develop practical strategies for their implementation in real-world scenarios.

Mesoporous silica nanospheres-mediated insecticide and antibiotics co-delivery system for synergizing insecticidal toxicity and reducing environmental risk of insecticide

Mesoporous silica nanoparticles (MSNs) are efficient carriers of drugs, and are promising in developing novel pesticide formulations. The cotton aphids Aphis gossypii Glover is a world devastating insect pest. It has evolved high level resistance to various insecticides thus resulted in the application of higher doses of insecticides, which raised environmental risk. In this study, the MSNs based pesticide/antibiotic delivery system was constructed for co-delivery of ampicillin (Amp) and imidacloprid (IMI). The IMI@Amp@MSNs complexes have improved toxicity against cotton aphids, and reduced acute toxicity to zebrafish. From the 16S rDNA sequencing results, Amp@MSNs, prepared by loading ampicillin to the mesoporous of MSNs, greatly disturbed the gut community of cotton aphids. Then, the relative expression of at least 25 cytochrome P450 genes of A. gossypii was significantly suppressed, including CYP6CY19 and CYP6CY22, which were found to be associated with imidacloprid resistance by RNAi. The bioassay results indicated that the synergy ratio of ampicillin to imidacloprid was 1.6, while Amp@MSNs improved the toxicity of imidacloprid by 2.4-fold. In addition, IMI@Amp@MSNs significantly improved the penetration of imidacloprid, and contributed to the amount of imidacloprid delivered to A. gossypii increased 1.4-fold. Thus, through inhibiting the relative expression of cytochrome P450 genes and improving penetration of imidacloprid, the toxicity of IMI@Amp@MSNs was 6.0-fold higher than that of imidacloprid. The greenhouse experiments further demonstrated the enhanced insecticidal activity of IMI@Amp@MSNs to A. gossypii. Meanwhile, the LC50 of IMI@Amp@MSNs to zebrafish was 3.9-fold higher than that of IMI, and the EC50 for malformation was 2.8-fold higher than IMI, respectively, which indicated that the IMI@Amp@MSNs complexes significantly reduced the environmental risk of imidacloprid. These findings encouraged the development of pesticide/antibiotic co-delivery nanoparticles, which would benefit pesticide reduction and environmental safety.

Chlorpyrifos enrichment enhances tolerance of Anabaena sp. PCC 7119 to dimethoate

Organophosphorus (OP) insecticides are widely used for on-field pest control, constituting about 38% of global pesticide consumption. Insecticide tolerance has been recorded in microorganisms isolated from the contaminated soil. However, the cross-tolerance of laboratory-enriched cultures remains poorly understood. A chlorpyrifos tolerant (T) strain of Anabaena sp. PCC 7119 was developed through continuous enrichment of the wild strain (W). The cross-tolerance of the T strain to the OP insecticide dimethoate was assessed by measuring photosynthetic performance, key enzyme activities and degradation potential. The presence of dimethoate led to a significant reduction in the growth and pigment content of the W strain. In contrast, the T strain demonstrated improved growth and metabolic performance. Chl a and carotenoids were degraded faster than phycobiliproteins in both strains. The T strain exhibited superior photosynthetic performance, metabolic efficiency and photosystem functions, than of W strain, at both the tested dimethoate concentrations (100 and 200 μM). The treated T strain had more or less a normal OJIP fluorescence transient and bioenergetic functions, while the W strain showed a greater fluorescence rise at ≤ 300 μs indicating the inhibition of electron donation to PS II, and at 2 ms due to reduced electron release beyond QA. The T strain had significantly higher levels of esterase and phosphatases, further enhanced by insecticide treatment. Dimethoate degradation efficiency of the T strain was significantly higher than of the W strain. T strain also removed chlorpyrifos more efficiently than W strain at both the tested concentrations. The BCFs of both chlorpyrifos and dimethoate were lower in the T strain compared to the W strain. These findings suggest that the enriched strain exhibits promising results in withstanding dimethoate toxicity and could be explored for its potential as a bioremediating organism for OP degradation.

The function of microbial enzymes in breaking down soil contaminated with pesticides: a review

The use of pesticides and the subsequent accumulation of residues in the soil has become a worldwide problem. Organochlorine (OC) pesticides have spread widely in the environment and caused contamination from past agricultural activities. This article reviews the bioremediation of pesticide compounds in soil using microbial enzymes, including the enzymatic degradation pathway and the recent development of enzyme-mediated bioremediation. Enzyme-mediated bioremediation is divided into phase I and phase II, where the former increases the solubility of pesticide compounds through oxidation-reduction and hydrolysis reactions, while the latter transforms toxic pollutants into less toxic or nontoxic products through conjugation reactions. The identified enzymes that can degrade OC insecticides include dehalogenases, phenol hydroxylase, and laccases. Recent developments to improve enzyme-mediated bioremediation include immobilization, encapsulation, and protein engineering, which ensure its stability, recyclability, handling and storage, and better control of the reaction.

Biodegradation of pesticide in agricultural soil employing entomopathogenic fungi: Current state of the art and future perspectives

Pesticides play a pivotal role in agriculture for the effective production of various crops. The indiscriminate use of pesticides results in the significant bioaccumulation of pesticide residues in vegetables. This situation is beyond the control of consumers and poses a serious health issue for human beings. Occupational exposure to pesticides may occur for farmers, agricultural workers, and industrial producers of pesticides. This occupational exposure primarily causes food and water contamination that gets into humans and environmental pollution. Depending on the toxicity of pesticides, the causes and effects differ in the environment and in human health. The number of criteria used and the method of implementation employed to assess the effect of pesticides on humans and the environment have been increasing, as they may provide characterization of pesticides that are already on the market as well as those that are on the way. The biological control of pests has been increasing nowadays to combat all these effects caused by synthetic pesticides. Myco-biocontrol has received great attention in research because it has no negative impact on humans, the environment, or non-target species. Entomopathogenic fungi are microbes that have the ability to kill insect pests. Fungi also make enzymes like the lytic enzymes, esterase, oxidoreductase, and cytochrome P450, which react with chemical residues in the field and break them down into nontoxic substances. In this review, the authors looked at how entomopathogenic fungi break down insecticides in the environment and how their enzymes break down insecticides on farms.

Microbiology and Biochemistry of Pesticides Biodegradation

Pesticides are chemicals used in agriculture, forestry, and, to some extent, public health. As effective as they can be, due to the limited biodegradability and toxicity of some of them, they can also have negative environmental and health impacts. Pesticide biodegradation is important because it can help mitigate the negative effects of pesticides. Many types of microorganisms, including bacteria, fungi, and algae, can degrade pesticides; microorganisms are able to bioremediate pesticides using diverse metabolic pathways where enzymatic degradation plays a crucial role in achieving chemical transformation of the pesticides. The growing concern about the environmental and health impacts of pesticides is pushing the industry of these products to develop more sustainable alternatives, such as high biodegradable chemicals. The degradative properties of microorganisms could be fully exploited using the advances in genetic engineering and biotechnology, paving the way for more effective bioremediation strategies, new technologies, and novel applications. The purpose of the current review is to discuss the microorganisms that have demonstrated their capacity to degrade pesticides and those categorized by the World Health Organization as important for the impact they may have on human health. A comprehensive list of microorganisms is presented, and some metabolic pathways and enzymes for pesticide degradation and the genetics behind this process are discussed. Due to the high number of microorganisms known to be capable of degrading pesticides and the low number of metabolic pathways that are fully described for this purpose, more research must be conducted in this field, and more enzymes and genes are yet to be discovered with the possibility of finding more efficient metabolic pathways for pesticide biodegradation.

Are biopesticides safe for the environment? Effects of pyrethrum extract on the non-target species Daphnia magna

Biopesticides are natural compounds considered more safe and sustainable for the environment. However, it is also important to evaluate the potential risk in non-target organisms. Pyrethrum extract (PE) is a biopesticide, widely used for agriculture, veterinary, and aquaculture. This work aimed to evaluate acute (0.6 - 40.0 µg/L; 96 h; E(L)C₅₀ toxicity) and sub-chronic (0.7 - 1.1 µg/L; 10 d; life-history parameters) effects of PE on Daphnia magna. Moreover, a biomarkers approach using antioxidant and biotransformation capacity, lipid peroxidation (LPO), neurotoxicity, and energy reserves content were evaluated. Acute effects (mortality, changes in swimming behavior, oxidative stress, lipid peroxidation, neurotoxicity) were recorded with the increase in PE concentration. Sub-chronic assay showed an increase in energy reserves content, antioxidant parameters, and LPO demonstrating that PE unbalances oxidative metabolism. This study can conclude that PE potentiates toxic effects in D. magna and demonstrates the vulnerability of a non-target organism to PE that is considered environmentally safe.

Biodegradation of monocrotophos by Brucella intermedia Msd2 isolated from cotton plant

Widespread and inadequate use of Monocrotophos has led to several environmental issues. Biodegradation is an ecofriendly method used for detoxification of toxic monocrotophos. In the present study, Msd2 bacterial strain was isolated from the cotton plant growing in contaminated sites of Sahiwal, Pakistan. Msd2 is capable of utilizing the monocrotophos (MCP) organophosphate pesticide as its sole carbon source for growth. Msd2 was identified as Brucella intermedia on the basis of morphology, biochemical characterization and 16S rRNA sequencing. B. intermedia showed tolerance of MCP up to 100 ppm. The presence of opd candidate gene for pesticide degradation, gives credence to B. intermedia as an effective bacterium to degrade MCP. Screening of the B. intermedia strain Msd2 for plant growth promoting activities revealed its ability to produce ammonia, exopolysaccharides, catalase, amylase and ACC-deaminase, and phosphorus, zinc and potassium solubilization. The optimization of the growth parameters (temperatures, shaking rpm, and pH level) of the MCP-degrading isolate was carried out in minimal salt broth supplemented with MCP. The optimal pH, temperature, and rpm for Msd2 growth were observed as pH 6, 35 °C, and 120 rpm, respectively. Based on optimization results, batch degradation experiment was performed. Biodegradation of MCP by B. intermedia was monitored using HPLC and recorded 78% degradation of MCP at 100 ppm concentration within 7 days of incubation. Degradation of MCP by Msd2 followed the first order reaction kinetics. Plant growth promoting and multi-stress tolerance ability of Msd2 was confirmed by molecular analysis. It is concluded that Brucella intermedia strain Msd2 could be beneficial as potential biological agent for an effective bioremediation for polluted environments.

Simultaneous determination of benzothiazoles, benzotriazoles, and benzotriazole UV absorbers by solid-phase extraction-gas chromatography-mass spectrometry

Benzotriazoles (BTRs), benzothiazoles (BTHs), and benzotriazole ultraviolet absorbers (BUVs) are common products in plastic rubber and personal care products. Due to their toxicity and bioaccumulation, they have been identified as emerging contaminants (ECs) in the environment. Solid-phase microextraction (SPME) and solid-phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) were used for the enrichment and detection of the contaminants in seawater and sediment, respectively. The conditions of SPE and SPME were optimized in terms of material, temperature, time, pH, ionic strength, extraction solvent, and elution solvent. Although SPME requires a small sample volume, it is not reliable for the extraction efficiency and reproducibility of BTHs, BTRs, and BUVs in seawater. However, the precision of SPE-GC-MS for the determination of BTHs, BTRs, and BUVs was around 10%, with recoveries of 67.40-102.3% and 77.35-101.8% in seawater and sediment, respectively. The limits of detection of 14 contaminants in seawater and sediment were 0.03-0.47 ng/L and 0.01-0.58 ng/g, respectively. Secondly, BTHs, BTRs, and BUVs were detected with low ecological risk when SPE-GC-MS was applied to the analysis of seawater and sediment samples from the Yangtze estuary and its adjacent areas. The SPE-GC-MS was highly precise with lower detection limits relative to previous studies and thus was able to meet the requirements for the detection of BTHs, BTRs, and BUVs in seawater and sediments.

Ameliorating SERS Sensitivity for Pesticide Malathion Detection with Synergistic Boosting Effect by Hydrogen Cations and Chloride Anions

Although SERS has been widely recognized as one of the highly sensitive analytical methods that can be deployed in the field with high sensitivity and short analysis time, reports regarding the fast determination of malathion at low concentrations are still scarce. Here, in this work, the solution pH and various halogen co-adsorbates were explored to promote the SERS signal of malathion using the citrate-reduced Ag NPs. It was found that chloride anions were the most efficient signal booster among the three halogen ions screened. Further examination of the SERS profile of the malathion in the presence of different halogen species found that the stretching mode of the P-S bond shifted to a lower frequency with Cl^-, which may imply closer (and stronger) binding of malathion to the Ag NPs. This concurs with literature reports that halogen ions could facilitate the adsorption of a certain analyte onto the SERS substrate. In addition, hydrogen ions showed a synergistic effect on SERS signal enhancement when combined with chloride anions. At optimum conditions, the malathion could be detected with a limit of detection (LOD) of 3 ppb. Malathion-spiked cherry tomatoes and oranges were analyzed, and the recovery rates were found to be within 85-100%.

Latest eco-friendly approaches for pesticides decontamination using microorganisms and consortia microalgae: A comprehensive insights, challenges, and perspectives

Pesticides are chemical compounds that are considered toxic to many organisms, including humans. Their elimination from polluted sites attracted the attention of Scientifics in the last decade; Among the various methods used to decontaminate pesticides from the environment, the microbial-algae consortium is a promising bioremediation technology, which implies several advantages as an eco-friendly process that generate biomass produced that could be valorized in the form of bioenergy, In this review, we will discuss the latest eco-friendly approaches using microorganisms to remediate sites contaminated by pesticides, and shows the ability of microbial, algae and their consortium to remove pesticides and the role of different enzymes in degradation processes.

Mycodegradation of diazinon pesticide utilizing fungal strains isolated from polluted soil

The current study aimed to isolate biodegradable soil fungi capable of metabolizing diazinon. The collected soil samples were investigated for diazinon pollution to detect the pesticide level in the polluted soil samples. Food poisoning techniques were utilized to preliminary investigate the biodegradation efficiency of the isolated fungal strains to diazinon pesticide using solid and liquid medium and also to detect their tolerance to different concentrations. GC-MS analysis of control and treated flasks were achieved to determine the diazinon residues for confirmation of the biodegradation efficiency. The total diazinon residues in the collected soil samples was found to be 0.106 mg/kg. Out of thirteen fungal strains isolated form diazinon polluted soils, six strains were potentially active in diazinon biodegradation. Food poisoning technique showed that A. niger, B. antennata, F. graminearum, P. digitatum, R. stolonifer and T. viride strains recorded fungal growth diameters of 65.2 ± 0.18, 57.5 ± 0.41, 47.2 ± 0.36, 56.5 ± 0.27, 85.0 ± 0.01, 85.0 ± 0.06 mm respectively in the treated group which were non significantly different compared to that of control (P > 0.05), indicating the high efficiency of these strains in diazinon degradation compared to the other isolated strains. GC-MS analysis revealed that B. antennata was the most efficient strain in diazinon degradation recording 32.24 ± 0.15 ppm concentration after 10 days incubation. Linear regression analysis confirmed that B. antennata was the most effective biodegradable strain recording the highest diazinon dissipation (83.88%) with the lowest T_1/2 value of 5.96 days while T. viride, A. niger, R. stolonifer and F. graminearum exhibited a high biodegradable activities reducing diazinon to 80.26%, 78.22%, 77.36% and 75.43% respectively after 10 days incubation. In conclusion, these tolerant fungi could be considered as promising, eco-friendly and biodegradable fungi for the efficient and potential removal of hazardous diazinon from polluted soil.

Organophosphate pesticides in South African eutrophic estuaries: Spatial distribution, seasonal variation, and ecological risk assessment

The seasonal variation, spatial distribution, and ecological risks of thirteen organophosphate pesticides (OPPs) were studied in the Sundays and Swartkops estuaries in South Africa. Ten pesticides were detected in surface water samples from both estuaries, while all OPPs were detected in sediments. The highest concentration of OPPs (18.8 μg pyrazophos L^-1) was detected in surface water samples from Swartkops Estuary, while 48.7 μg phosalone kg^-1 dw was the highest in sediments collected from Sundays Estuary. There was no clear seasonal pattern in OPPs occurrence in surface water from both systems. However, their occurrence in sediments was in the following order: winter > autumn > summer > spring, perhaps indicating major pesticide input in the winter seasons. Results from ecological risk assessment showed that pyraclofos and chlorpyrifos (CHL) in surface water from both systems are respectively likely to cause high acute and chronic toxicity to fish (risk quotient - RQ > 1). For sediments of both estuaries, the highest acute and chronic RQs for fish were calculated for isazophos and CHL respectively. The majority of the detected OPPs in sediments posed potential high risks to Daphnia magna from both systems. These results suggest that these aquatic organisms (fish, and Daphnia), if present in the studied estuaries, can develop certain forms of abnormalities due to OPP exposure. To this end, proper measures should be taken to reduce OPP input into the estuarine systems.

Biodegradation of malathion by Micrococcus sp. strain MAGK3: kinetics and degradation fragments

Malathion is widely used as an agricultural insecticide, but its toxic nature makes it a serious environmental contaminant. To screen indigenous bacteria for malathion degradation, a strain MAGK3 capable of utilizing malathion as its sole carbon and energy source was isolated from Pennisetum glaucum agricultural soil. Based on morphological and biochemical characteristics and 16S rDNA sequence analysis, strain MAGK3 was identified as Micrococcus aloeverae. The strain was cultured in the presence of malathion under aerobic and energy-restricting conditions, and it grew well in MSM containing malathion (1000 µl/L), showing the highest specific growth rate at 500 µl/L_. Reverse-phase UHPLC-DAD analysis indicated that 100%, 90.48%, 84.27%, 75.46%, 66.65%, and 31.96% of malathion were degraded within 15 days in liquid culture augmented with 50, 100, 200, 300, 500, and 1000 µl/L concentrations of commercial malathion, respectively. Confirmation of malathion degradation to malathion mono, diacids, and phosphorus moiety was performed by Q-TOF-MS analysis, and a pathway of biodegradation was proposed. The influence of co-substrates was also examined to optimize biodegradation further. Kinetic studies based on different models were conducted, and the results demonstrated good conformity with the first-order model. Malathion degradation process by Micrococcus aloeverae was characterized by R² of 0.95, and the initial concentration was reduced by 50% i.e. (DT50) in 8.11 d at an initial concentration of 500 µl/L. This establishes the Micrococcus sp. as a potent candidate for active bioremediation of malathion in liquid cultures as it can withstand high malathion load and can possibly impact the development strategies of bioremediation for its elimination.

Optimizing the malathion degrading potential of a newly isolated Bacillus sp. AGM5 based on Taguchi design of experiment and elucidation of degradation pathway

Malathion, a pesticide used to control pests in crops, vegetables, fruits, and livestock. Its widespread and indiscriminate usage has ensued in different ecological issues, thus, it's vital to remediate this insecticide. Malathion degrading bacterium Bacillus sp. AGM5, isolated from pesticide contaminated agricultural field was cultured in presence of different malathion concentrations under aerobic and energy restrictive conditions and was found effective at malathion degradation. Recovered malathion was extracted based on QuEChERS approach and then analyzed by UHPLC. About 39.5% of malathion biodegradation was observed at 300 µlL^-1 after 96 h of incubation with the tested bacteria which increased to 58.5% and 72.5% after 240, and 360 h of incubation, respectively. To further enhance malathion biodegradation, the effects of co-substrates, pH, temperature, initial malathion concentration, agitation (rpm), and inoculum size were evaluated using Taguchi methodology. Taguchi DOE's ability to predict the optimal response was established experimentally via optimised levels of these factors (glucose-0.1%, yeast extract-0.1%, inoculum size-2% wv^-1, malathion concentration 300 µlL^-1, rpm-150, pH-7, temperature 40 °C), whereby biodegradation rate was enhanced to 95.49% after 38 h. Confirmation of malathion biodegradation was performed by UHPLC, Q-TOF-MS, GC-MS analysis and a possible degradation pathway was proposed for malathion biodegradation. First order kinetic model was appropriate to describe malathion biodegradation. The Taguchi DOE proved to be viable tool for optimizing culture conditions and analysing the interactions between process parameters in order to attain the best feasible combination for maximum malathion degradation. These results could influence the development of a bioremediation strategy.

Microbial Technologies Employed for Biodegradation of Neonicotinoids in the Agroecosystem

Neonicotinoids are synthetic pesticides widely used for the control of various pests in agriculture throughout the world. They mainly attack the nicotinic acetylcholine receptors, generate nervous stimulation, receptor clot, paralysis and finally cause death. They are low volatile, highly soluble and have a long half-life in soil and water. Due to their extensive use, the environmental residues have immensely increased in the last two decades and caused many hazardous effects on non-target organisms, including humans. Hence, for the protection of the environment and diversity of living organism's the degradation of neonicotinoids has received widespread attention. Compared to the other methods, biological methods are considered cost-effective, eco-friendly and most efficient. In particular, the use of microbial species makes the degradation of xenobiotics more accessible fast and active due to their smaller size. Since this degradation also converts xenobiotics into less toxic substances, the various metabolic pathways for the microbial degradation of neonicotinoids have been systematically discussed. Additionally, different enzymes, genes, plasmids and proteins are also investigated here. At last, this review highlights the implementation of innovative tools, databases, multi-omics strategies and immobilization techniques of microbial cells to detect and degrade neonicotinoids in the environment.

Myco-remediation: A mechanistic understanding of contaminants alleviation from natural environment and future prospect

Industrialization and modernization of agricultural systems contaminated lithosphere, hydrosphere, and biosphere of the Earth. Sustainable remediation of contamination is essential for environmental sustainability. Myco-remediation is proposed to be a green, economical, and efficient technology over conventional remediation technologies to combat escalating pollution problems at a global scale. Fungi can perform remediation of pollutants through several mechanisms like biosorption, precipitation, biotransformation, and sequestration. Myco-remediation significantly removes or degrades metal metals, persistent organic pollutants, and other emerging pollutants. The current review highlights the species-specific remediation potential, influencing factors, genetic and molecular control mechanism, applicability merits to enhance the bioremediation efficiency. Structure and composition of fungal cell wall is crucial for immobilization of toxic pollutants and a subtle change on fungal cell wall structure may significantly affect the immobilization efficiency. The utilization protocol and applicability of enzyme engineering and myco-nanotechnology to enhance the bioremediation efficiency of any potential fungus was proposed. It is advocated that the association of hyper-accumulator plants with plant growth-promoting fungi could help in an effective cleanup strategy for the alleviation of persistent soil pollutants. The functions, activity, and regulation of fungal enzymes in myco-remediation practices required further research to enhance the myco-remediation potential. Study of the biotransformation mechanisms and risk assessment of the products formed are required to minimize environmental pollution. Recent advancements in molecular "Omic techniques"and biotechnological tools can further upgrade myco-remediation efficiency in polluted soils and water.

Prospect and Challenges for Sustainable Management of Climate Change-Associated Stresses to Soil and Plant Health by Beneficial Rhizobacteria

Climate change imposes biotic and abiotic stresses on soil and plant health all across the planet. Beneficial rhizobacterial genera, such as Bacillus, Pseudomonas, Paraburkholderia, Rhizobium, Serratia, and others, are gaining popularity due to their ability to provide simultaneous nutrition and protection of plants in adverse climatic conditions. Plant growth-promoting rhizobacteria are known to boost soil and plant health through a variety of direct and indirect mechanisms. However, various issues limit the wider commercialization of bacterial biostimulants, such as variable performance in different environmental conditions, poor shelf-life, application challenges, and our poor understanding on complex mechanisms of their interactions with plants and environment. This study focused on detecting the most recent findings on the improvement of plant and soil health under a stressful environment by the application of beneficial rhizobacteria. For a critical and systematic review story, we conducted a non-exhaustive but rigorous literature survey to assemble the most relevant literature (sorting of a total of 236 out of 300 articles produced from the search). In addition, a critical discussion deciphering the major challenges for the commercialization of these bioagents as biofertilizer, biostimulants, and biopesticides was undertaken to unlock the prospective research avenues and wider application of these natural resources. The advancement of biotechnological tools may help to enhance the sustainable use of bacterial biostimulants in agriculture. The perspective of biostimulants is also systematically evaluated for a better understanding of the molecular crosstalk between plants and beneficial bacteria in the changing climate towards sustainable soil and plant health.

Mechanistic understanding of the pollutant removal and transformation processes in the constructed wetland system

Constructed wetland systems (CWs) are biologically and physically engineered systems to mimic the natural wetlands which can potentially treat the wastewater from the various point and nonpoint sources of pollution. The present study aims to review the various mechanisms involved in the different types of CWs for wastewater treatment and to elucidate their role in the effective functioning of the CWs. Several physical, chemical, and biological processes substantially influence the pollutant removal efficiency of CWs. Plants species Phragmites australis, Typha latifolia, and Typha angustifolia are most widely used in CWs. The rate of nitrogen (N) removal is significantly affected by emergent vegetation cover and type of CWs. Hybrid CWs (HCWS) removal efficiency for nutrients, metals, pesticides, and other pollutants is higher than a single constructed wetland. The contaminant removal efficiency of the vertical subsurface flow constructed wetlands (VSSFCW) commonly used for the treatment of domestic and municipal wastewater ranges between 31% and 99%. Biochar/zeolite addition as substrate material further enhances the wastewater treatment of CWs. Innovative components (substrate materials, plant species) and factors (design parameters, climatic conditions) sustaining the long-term sink of the pollutants, such as nutrients and heavy metals in the CWs should be further investigated in the future. PRACTITIONER POINTS: Constructed wetland systems (CWs) are efficient natural treatment system for on-site contaminants removal from wastewater. Denitrification, nitrification, microbial and plant uptake, sedimentation and adsorption are crucial pollutant removal mechanisms. Phragmites australis, Typha latifolia, and Typha angustifolia are widely used emergent plants in constructed wetlands. Hydraulic retention time (HRT), water flow regimes, substrate, plant, and microbial biomass substantially affect CWs treatment performance.

Chloroorganic (DDT) and organophosphate (malathion) insecticides impair the motor function of the bovine cervix

Dichlorodiphenyltrichloroethane (DDT) is a representative organochlorine insecticide and a known endocrine disruptor. Malathion is an organophosphate insecticide and a next-generation pesticide. Previously, it was shown that oxytocin (OT) and prostaglandins (PGs) are involved in the mechanism of the adverse effect of DDT on bovine myometrial contractions. However, disruption of myometrial contractions without disruption of cervical activity may not be sufficient to cause preterm delivery. Hence, the aim of this study was to determine the effects of insecticides on the function of the bovine cervix at preovulation period. Bovine cervical cells or strips were treated with DDT or malathion (0.1-100 ng/ml), and neither DDT nor malathion (each at a dose of 100 ng/ml) affected the viability of cervical cells. Malathion (0.1-10 ng/ml) and the high doses of DDT (10 ng/ml) decreased the force of cervical contractions, in contrast to a low dose of DDT (0.1 ng/ml). Both insecticides also decreased the mRNA expression of the OT receptor and the level of the second messenger (inositol triphosphate, IP3). Moreover, DDT decreased the amount of other second messengers (diacylglycerol, DAG), while malathion decreased the amount of gap junction protein (GAP). Only malathion increased PGE2 and decreased PGF2α secretion, while neither insecticide had an effect on both prostaglandins synthesis. Both DDT and malathion impaired cervical contractions, secretory function and cellular signalling. It is also possible that malathion-mediated induction of locally produced PGE2 can be followed by cervical softening. Admittedly it was shown that DDT and malathion can evoke failures in the regulation of motor function of cervix during oestrus cycle, while their harmful effect on gestation can be also not excluded.

Towards sustainable agriculture with carbon sequestration, and greenhouse gas mitigation using algal biochar

With the increase in the world's population, demand for food and other products is continuously rising. This has put a lot of pressure on the agricultural sector. To fulfill these demands, the utilization of chemical fertilizers and pesticides has also increased. Consequently, to overcome the adverse effects of agrochemicals on our environment and health, there has been a shift towards organic fertilizers or other substitutes, which are ecofriendly and help to maintain a sustainable environment. Microalgae have a very high potential of carbon dioxide (CO₂) capturing and thus, help in mitigating the greenhouse effect. It is the most productive biological system for generating biomass. The high growth rate and higher photosynthetic efficiency of the algal species compared to the terrestrial plants make them a wonderful alternative towards a sustainable environment. Moreover, they could be cultivated in photobioreactors or open ponds, which in turn reduce the demand for arable land. Biochar derived from algae is high in nutrients and exhibits the property of ion exchange. Therefore, it can be utilized for sustainable agriculture by partial substituting the chemical fertilizers that degrade the fertility of the soil in the long run. This review provides a detailed insight on the properties of algal biochar as a potential fertilizer for sustainable agriculture. Application of algal biochar in bio-refinery and its economic aspects, challenges faced and future perspective are also discusses in this study.

Multiple Roles of Mesoporous Silica in Safe Pesticide Application by Nanotechnology: A Review

Pollution related to pesticides has become a global problem due to their low utilization and non-targeting application, and nanotechnology has shown great potential in promoting sustainable agriculture. Nowadays, mesoporous silica-based nanomaterials have garnered immense attention for improving the efficacy and safety of pesticides due to their distinctive advantages of low toxicity, high thermal and chemical stability, and particularly size tunability and versatile functionality. Based on the introduction of the structure and synthesis of different types of mesoporous silica nanoparticles (MSNs), the multiple roles of mesoporous silica in safe pesticide application using nanotechnology are discussed in this Review: (i) as nanocarrier for sustained/controlled delivery of pesticides, (ii) as adsorbent for enrichment or removal of pesticides in aqueous media, (iii) as support of catalysts for degradation of pesticide contaminants, and (iv) as support of sensors for detection of pesticides. Several scientific issues, strategies, and mechanisms regarding the application of MSNs in the pesticide field are presented, with their future directions discussed in terms of their environmental risk assessment, in-depth mechanism exploration, and cost-benefit consideration for their continuous development. This Review will provide critical information to related researchers and may open up their minds to develop new advances in pesticide application.

The Chemical Compounds from Degradation of Profenofos and Malathion by Indigenous Bacterial Consortium

The Indonesian Pesticide Regulations state that Malathion and Profenofos have been restricted in their use for agriculture because of is bioaccumulative in ecological systems. Cleaning technology using microorganisms is an effective solution for cleaning pesticide residues. This study aims to identify the bacteria that degrade and the degradation process of Malathion and Profenophos into non-toxic compounds. The research method was experimental, identification of bacteria by 16S-rRNA gene analysis, degradation ability by GC MS. The results of phylogenetic tree analysis showed that the tested bacteria were closely related to Oceanobacillus iheyenis (RPL1) and Exiquobacterium profundum (RPL5) with a similarity level of 87% and 99%. The two bacteria are used as a consortium of test bacteria. The results of degradation based on the observation chromatogram T = 0 showed that the Malathion compound C10H19O6PS2 or butanedioic acid [(dimethoxyphosphinothioyl) thio]) was detected at peak 4, real-time = 19,675, area% = 7.37 and Profenofos compound C11H15BrClO3PSO-(4-Bromo-2-chlorophenyl)o-ethyl s-propyl thiophosphate, peak 8, real-time = 23,957, area% = 6.91. Likewise, the chromatogram results at T = 96 were still detected Malathion ((dimethoxyphosphinothioyl) thio) at peak 14, real-time = 19,675, area% = 2.25, and Profenofos (o- (4-Bromo-2-chlorophenyl)) o – ethyl. s – propyl thiophosphate) peak = 22 real-time = 23,951, area% = 2,2. However, the observation of T = 192 hours, Malathion and Profenofos compounds were not detected. The conclusion showed that the consortium bacteria were able to completely degrade Malathion and Profenophos within 192 hours.

Malathion biodegradation by a psychrotolerant bacteria Ochrobactrum sp. M1D and metabolic pathway analysis

An organophosphorus pesticide malathion biodegradation was investigated by using the bacteria Ochrobactrum sp. M1D isolated from a soil sample of peach orchards in Palampur, District Kangra, Himachal Pradesh (India). The bacterium was able to utilize malathion as the sole source of carbon and energy. The isolated bacterium was found psychrotolerant and could degrade 100% of 100 mg l^-1 malathion in minimal salt medium at 20°C, pH 7·0 within 12 days with no major significant metabolites left at the end of the study. Through GCMS analysis, methyl phosphate, diethyl maleate, and diethyl 2-mercaptosuccinate were detected and identified as the major pathway metabolites. Based on the GCMS profile, three probable degradation pathways were interpreted. The present study is the first report of malathion biodegradation at both the psychrophilic and mesophilic conditions by any psychrotolerant strain and also through multiple degradation pathways. In the future, the strain can be explored to bio-remediate the malathion contaminated soil in the cold climatic region and to utilize the enzymatic systems for advanced biotechnology applications.

Transformation of fluopyram during enzymatic hydrolysis of apple and its effect on polygalacturonase and apple juice yield

China is one of the largest apple-growing areas in the world. Fluopyram (FLP) is a novel pesticide that has been widely used in agriculture. This work investigated the behavior of pesticides during enzymatic hydrolysis of apple juice and its effect on polygalacturonase (PG), apple juice yield, and flavor. The study findings revealed that 27.5% to 34.2% FLP was degraded during the enzymatic hydrolysis of apple. The three degradation products (P1, P2, and P3) were identified by a hybrid ion trap-orbitrap mass spectrometer. Based on toxicity assessment, it was found that carcinogenicity was higher for P2 and P3 than for FLP. Furthermore, FLP affected the yield and flavor of apple juice. FLP reduced yield by 4.8%, because FLP inhibited the activity of PG. Through molecular docking, it was found that there was an interaction between the active center of PG and FLP, resulting in a reduction in catalytic ability.

Whole genome strategies and bioremediation insight into dehalogenase-producing bacteria

An integral approach to decoding both culturable and uncultured microorganisms' metabolic activity involves the whole genome sequencing (WGS) of individual/complex microbial communities. WGS of culturable microbes, amplicon sequencing, metagenomics, and single-cell genome analysis are selective techniques integrating genetic information and biochemical mechanisms. These approaches transform microbial biotechnology into a quick and high-throughput culture-independent evaluation and exploit pollutant-degrading microbes. They are windows into enzyme regulatory bioremediation pathways (i.e., dehalogenase) and the complete bioremediation process of organohalide pollutants. While the genome sequencing technique is gaining the scientific community's interest, it is still in its infancy in the field of pollutant bioremediation. The techniques are becoming increasingly helpful in unraveling and predicting the enzyme structure and explore metabolic and biodegradation capabilities.

The effect of the pesticide delivery method on the microbial community of field soil

The study deals with the effects of herbicides (metribuzin, tribenuron-methyl, fenoxaprop-P-ethyl) and fungicides (tebuconazole, epoxiconazole, azoxystrobin) applied to soil as free pesticides or as slow release formulations embedded in a biodegradable composite matrix on the structure of the soil microbial community. The matrix consisted of a natural biopolymer poly-3-hydroxybutyrate [P(3HB)] and a filler-one of the natural materials (peat, clay, and wood flour). The soil microbial community was characterized, including the major eco-trophic groups of bacteria, dominant taxa of bacteria and fungi, and primary P(3HB)-degrading microorganisms, such as Pseudomonas, Bacillus, Pseudarthrobacter, Streptomyces, Penicillium, and Talaromyces. The addition of free pesticides adversely affected the abundance of soil microorganisms; the decrease varied from 1.4 to 56.0 times for different types of pesticides. The slow release pesticide formulations, in contrast to the free pesticides, exerted a much weaker effect on soil microorganisms, no significant inhibition in the abundance of saprotrophic bacteria was observed, partly due to the positive effects of the composite matrix (polymer/natural material), which was a supplementary substrate for microorganisms. The slow release fungicide formulations, like the free fungicides, reduced the total abundance of fungi and inhibited the development of the phytopathogens Fusarium and Alternaria. Thus, slow release formulations of pesticides preserve the bioremediation potential of soil microorganisms, which are the main factor of removing xenobiotics from the biosphere.

Enantiomeric separation of malathion and malaoxon and the chiral residue analysis in food and environmental matrix

Malathion is a widely used chiral phosphorus insecticide, which has a more toxic chiral metabolite malaoxon. In this work, the enantiomers of malathion and malaoxon were separated by high-performance liquid chromatography-mass/mass (HPLC-MS/MS) with chiral columns using acetonitrile/water or methanol/water as mobile phase, and the chromatographic conditions were optimized. Based on the chiral separation, the chiral residue analysis methods for the enantiomers in soil, fruit, and vegetables were set up. Two pairs of the enantiomers were better separated on CHIRALPAK IC chiral column, and baseline simultaneous separations of malathion and malaoxon enantiomers were achieved with acetonitrile/water (40/60, v/v) as mobile phase at a flow rate of 0.5 mL/min. The elution orders were -/+ for both malathion and malaoxon measured by an optical rotation detector. The chiral residue analysis in soil, fruit, and vegetables was validated by linearity, recovery, precision, limit of detection (LOD), and limit of quantification (LOQ). The LODs and LOQs for the enantiomers of malathion were 1 μg/kg and 3-5 μg/kg and 0.08 μg/kg and 0.20-0.25 μg/kg for malaoxon enantiomers. Good linear calibration curves for each enantiomer in the matrices were obtained within the concentration range of 0.02-12 mg/L. The mean recoveries of the enantiomers of malathion and malaoxon ranged from 82.26% to 109.04%, with RSDs of 0.71-8.63%.The results confirmed that this method was capable of simultaneously determining the residue of malathion and malaoxon in food and environmental matrix on an enantiomeric level.