Biodegradation of organophosphorus insecticide chlorpyrifos into a major fuel additive 2,4-bis(1,1 dimethylethyl) phenol using white-rot fungal strain Trametes hirsuta MTCC-1171

Achromobacter xylosoxidans and Stutzerimonas stutzeri from the phyllosphere of Eichhornia crassipes (water hyacinth) degrade chlorpyrifos as consortia

Organophosphates (OPs) constitute a significant proportion of pesticides currently used worldwide in agriculture. Widespread and repeated application of these insecticides contaminates the soil and water, posing significant non-target toxicity risks to other organisms within the ecosystem. Acute pesticide exposure causes toxicity to insects, plants, animals, and humans, and thus emphasizes the need for sustainable management. Bacterial degradation of pesticides has been considered as a preferred strategy. In the present study, the phyllosphere of water hyacinth (Eichhornia crassipes) was explored for the chlorpyrifos degrading bacteria using Culture-independent and culture-dependent methods. Culture-independent study revealed 44,514 operational taxonomic units (OTUs) that were classified into 16 phyla and 330 genera, with dominating genera such as Acinetobacter, Paenibacillus, Pseudomonas, Sphingobacterium, and Achromobacter. Culture-dependent method yielded Achromobacter xylosoxidans and Stutzerimonas stutzeri as chlorpyrifos tolerant and degraders. These isolated strains exhibited enhanced growth as a consortium with chlorpyrifos as the only carbon source. The consortia effectively degrade 98% of chlorpyrifos within seven days, indicating its potential for pesticide degradation. Proteomics analysis revealed upregulation of key enzymes implicated in chlorpyrifos degradation, such as phosphodiesterase, metallo-beta-lactamases and oxidoreductase. The down-regulation of stress-response proteins suggests an adaptive tolerance to the pesticide. This study justifies the potential of consortia of isolated strains in the degradation of chlorpyrifos and may be developed into a promising and eco-friendly approach for remediating chlorpyrifos-contaminated environments.

Comparative evaluation of biodegradation of chlorpyrifos by various bacterial strains: Kinetics and pathway elucidation

The present study focused on the isolation and identification of CP and TCP bacteria degrading bacteria from the rhizospheric zone of aromatic grasses i.e. palmarosa (Cymbopogon martinii (Roxb. Wats), lemongrass (Cymbopogon flexuosus) and vetiver (Chrysopogon zizaniodes (L.) Nash.). So that these isolates alone or in combination with the vegetation of aromatic grasses will be used to clean up CP-contaminated soils. The study also explored enzymatic activities, CO2 release, dechlorination potential, and degradation pathways of bacterial strains. A total of 53 CP-tolerant bacteria were isolated on their physical characteristics and their ability to degrade CP. The ten highly CP-tolerant isolates were Pseudomonas aeruginosa Pa608, three strains of Pseudomonas hibiscicola R4-721 from different rhizosphere, Enterococcus lectis PP2a, Pseudomonas monteilii NBFPALD_RAS131, Enterobacter cloacae L3, Stenotrophomonas maltophilia PEG-390, Escherichia coli ABRL132, and Escherichia coli O104:H4 strain FWSEC0009. The CO2 emission and phosphatase activities of the isolates varied from 3.1 to 8.6 μmol mL-1 and 12.3 to 31 μmol PNP h-1, respectively in the CP medium. The degradation kinetics of CP by these isolates followed a one-phase decay model with a dissipation rate ranging from 0.048 to 0.41 d-1 and a half-life of 1.7-14.3 days. The growth data fitted in the SGompertz equation showed a growth rate (K) of 0.21 ± 0.28 to 0.91 ± 0.33 d-1. The P. monteilii strain had a faster growth rate while E. coli ABRL132 had slower growth among the isolates. The rate of TCP accumulation calculated by the SGompertz equation was 0.21 ± 0.02 to 1.18 ± 0.19 d-1. The Pseudomonas monteilii showed a lower accumulation rate of TCP. Among these, four highly effective isolates were Pseudomonas aeruginosa Pa608, Pseudomonas monteilii NBFPALD_RAS131, Stenotrophomonas maltophilia PEG-390, and Pseudomonas hibiscicola R4-721. Illustrations of the degradation pathways indicated that the difference in metabolic pathways of each isolate was associated with their growth rate, phosphatase, dehydrogenase, oxidase, and dechlorination activities.

Insight into the environmental fate, hazard, detection, and sustainable degradation technologies of chlorpyrifos-an organophosphorus pesticide

Pesticides play a critical role in terms of agricultural output nowadays. On top of that, pesticides provide economic support to our farmers. However, the usage of pesticides has created a public health issue and environmental hazard. Chlorpyrifos (CPY), an organophosphate pesticide, is extensively applied as an insecticide, acaricide, and termiticide against pests in various applications. Environmental pollution has occurred because of the widespread usage of CPY, harming several ecosystems, including soil, sediment, water, air, and biogeochemical cycles. While residual levels in soil, water, vegetables, foodstuffs, and human fluids have been discovered, CPY has also been found in the sediment, soil, and water. The irrefutable pieces of evidence indicate that CPY exposure inhibits the choline esterase enzyme, which impairs the ability of the body to use choline. As a result, neurological, immunological, and psychological consequences are seen in people and the natural environment. Several research studies have been conducted worldwide to identify and develop CPY remediation approaches and its derivatives from the environment. Currently, many detoxification methods are available for pesticides, such as CPY. However, recent research has shown that the breakdown of CPY using bacteria is the most proficient, cost-effective, and sustainable. This current article aims to outline relevant research events, summarize the possible breakdown of CPY into various compounds, and discuss analytical summaries of current research findings on bacterial degradation of CPY and the potential degradation mechanism.

Recent advances in fungal xenobiotic metabolism: enzymes and applications

Fungi have been extensively studied for their capacity to biotransform a wide range of natural and xenobiotic compounds. This versatility is a reflection of the broad substrate specificity of fungal enzymes such as laccases, peroxidases and cytochromes P450, which are involved in these reactions. This review gives an account of recent advances in the understanding of fungal metabolism of drugs and pollutants such as dyes, agrochemicals and per- and poly-fluorinated alkyl substances (PFAS), and describes the key enzymes involved in xenobiotic biotransformation. The potential of fungi and their enzymes in the bioremediation of polluted environments and in the biocatalytic production of important compounds is also discussed.

Reusable carboxylesterase immobilized in ZIF for efficient degradation of chlorpyrifos in enviromental water

The past few decades have witnessed biodegradation of pesticides as a significant method in remediation of the environment for its specificity, efficiency and biocompatibility. However, the tolerability and recyclability of the enzymes in pesticide degradation and the development of enzymes that biodegrad pesticides are still urgent problems to be solved so far. Herein, a novel hyper-thermostable and chlorpyrifos-hydrolyzing carboxylesterase EstC was immobilized by biomineralization using zeolitic imidazolate framework (ZIF), one of the metal-organic frameworks (MOFs) with highly diverse structure and porosity. Compared with free enzyme, EstC@ZIF with a cruciate flower-like morphology presented scarcely variation in catalytic efficiency and generally improved the tolerance to organic solvents or detergents. Furthermore, there was scarcely decrease in the catalytic efficiency of EstC@ZIF and it also showed good reusability with about 50% residual activity after 12 continuous uses. Notably, EstC@ZIF could be used in actual water environment with an excellent value of degradation rate of 90.27% in 120 min, and the degradation efficiency remained about 50% after 9 repetitions. The present strategy of immobilizing carboxylesterase to treat pesticide-contaminated water broadens the method of immobilized enzymes on MOFs, and envisions its recyclable applicability in globe environmental remediation.

A systematic review on the implementation of advanced and evolutionary biotechnological tools for efficient bioremediation of organophosphorus pesticides

Ever since the concept of bioremediation was introduced, microorganisms, microbial enzymes and plants have been used as principal elements for Organophosphate pesticide (OPP) bioremediation. The enzyme systems and genetic profile of these microbes have been studied deeply in past years. Plant growth promoting rhizobacteria (PGPR) are considered as one of the potential candidates for OPP bioremediation and has been widely used to stimulate the phytoremediation potential of plants. Constructed wetlands (CWs) in OPP biodegradation have brought new prospects to microcosm and mesocosm based remediation strategies. Application of synthetic biology has provided a new dimension to the field of OPP bioremediation by introducing concepts like, gene manipulation andediting, expression and regulation of catabolic enzymes, implementation of whole-cell based and enzyme based biosensor systems for the detection and monitoring of OPP pollution in both terrestrial and aquatic environment. System biology and bioinformatics tools have rendered significant knowledge regarding the genetic, enzymatic and biochemical aspects of microbes and plants thereby, helping researchers to analyze the mechanism of OPP biodegradation. Structural biology has provided significant conceptual information regarding OPP biodegradation pathways, structural and functional characterization of metabolites and enzymes, enzyme-pollutant interactions, etc. Therefore, this review discussed the prospects and challenges of most advanced and high throughput strategies implemented for OPP biodegradation. The review also established a comparative analysis of various bioremediation techniques and highlighted the interdependency among them. The review highly suggested the simultaneous implementation of more than one remediation strategy or a combinational approach creating an advantageous hybrid technique for OPP bioremediation.

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.

Recent progress in key lignocellulosic enzymes: Enzyme discovery, molecular modifications, production, and enzymatic biomass saccharification

Lignocellulose, the most prevalent biomass on earth, can be enzymatically converted into carbohydrates for bioethanol production and other uses. Among lignocellulosic enzymes, endoglucanase, xylanase, and laccase are the key enzymes, owing to their ability to disrupt the main structure of lignocellulose. Recently, new discovery methods have been established to obtain key lignocellulosic enzymes with excellent enzymatic properties. Molecular modification of enzymes to modulate their thermostability, catalytic activity, and substrate specificity has been performed with protein engineering technology. In addition, the enzyme expression has been effectively improved through expression element screening and host modification, as well as fermentation optimization. Immobilization of enzymes, use of surfactants, synergistic degradation, and optimization of reaction conditions have addressed the inefficiency of enzymatic saccharification. In this review, recent advances in key lignocellulosic enzymes are summarized, along with future prospects for the development of super-engineered strains and integrative technologies for enzymatic biomass saccharification.

The growing concern of chlorpyrifos exposures on human and environmental health

Chlorpyrifos (CP) and its highly electrophilic intermediates are principal toxic metabolites. The active form of CP i.e. chlorpyrifos oxon (CP-oxon) is responsible for both the insecticidal activity and is also of greater risk when present in the atmosphere. Thus, the combined effects of both CP, CP-oxan, and other metabolites enhance our understanding of the safety and risk of the insecticide CP. They cause major toxicities such as AChE inhibition, oxidative stress, and endocrine disruption. Further, it can have adverse hematological, musculoskeletal, renal, ocular, and dermal effects. Excessive use of this compound results in poisoning and potentially kills a non-target species upon exposure including humans. Several examples of reactive metabolites toxicities on plants, aquatic life, and soil are presented herein. The review covers the general overview on reactive metabolites of CP, chemistry and their mechanism through toxic effects on humans as well as on the environment. Considerable progress has been made in the replacement or alternative to CP. The different strategies including antidote mechanisms for the prevention and treatment of CP poisoning are discussed in this review. The approach analyses also the active metabolites for the pesticide activity and thus it becomes more important to know the pesticide and toxicity dose of CP as much as possible.

Endocrine disrupting chemicals (EDCs) in environmental matrices: Occurrence, fate, health impact, physio-chemical and bioremediation technology

Endocrine disrupting chemicals (EDCs) are an emerging category of toxicity that adversely impacts humans and the environment's well-being. Diseases like cancer, cardiovascular risk, behavioral disorders, autoimmune defects, and reproductive diseases are related to these endocrine disruptors. Because these chemicals exist in known sources such as pharmaceuticals and plasticizers, as well as non-point sources such as agricultural runoff and storm water infiltration, the interactive effects of EDCs are gaining attention. However, the efficiency of conventional treatment methods is not sufficient to fully remediate EDCs from aqueous environments as the occurrence of EDC bioremediation and biodegradation is detected in remediated drinking water. Incorporating modification into current remediation techniques has to overcome challenges such as high energy consumption and health risks resulting from conventional treatment. Hence, the use of advanced psychochemical and biological treatments such as carbon-based adsorption, membrane technology, nanostructured photocatalysts, microbial and enzyme technologies is crucial. Intensifying environmental and health concerns about these mixed contaminants are primarily due to the lack of laws about acute concentration limits of these EDCs in municipal wastewater, groundwater, surface water, and drinking water. This review article offers evidence of fragmentary available data for the source, fate, toxicity, ecological and human health impact, remediation techniques, and mechanisms during EDC removal, and supports the need for further data to address the risks associated with the presence of EDCs in the environment. The reviews also provide comprehensive data for biodegradation of EDCs by using microbes such as fungi, bacteria, yeast, filamentous fungi, and their extracellular enzymes.

Effects of chlorpyrifos on the metabolic profiling of Bacillus megaterium strain RRB

Many microorganisms have been reported to degrade organic pollutants in the environment and plants, however, the specific information about the effect of organic pollutants on the metabolism of microorganisms is poorly investigated. In the present study, the effect of the pesticide chlorpyrifos on the metabolic profiling of Bacillus megaterium strain RRB was investigated using metabolomics. Our data show that chlorpyrifos acting as an energy source was readily concentrated in the strain RRB from the culture medium. During early cultivation, the shift in energy sources from tryptic soy broth to chlorpyrifos may temporarily cause the strain RRB to enter the starvation stage, where some synthesis-related amino acids and intermediates in the pathways of TCA cycle and pyridoxine metabolism were decreased. The increase of nucleotides and lysine may help the strain RRB cope with the starvation stage. During later cultivation, many metabolites including organic acids, nucleosides and sugar phosphates were gradually accumulated, which indicates that chlorpyrifos could be utilized by the stain RRB to generate metabolites bacteria needed. In addition, arginine acting as a nitrogen-storage amino acid was gradually decreased with later cultivation, suggesting that chlorpyrifos could not provide enough nitrogen for bacteria.

Assessment of the potential risk of leaching pesticides in agricultural soils: study case Tibasosa, Boyacá, Colombia

Agricultural soils need monitoring systems to address pesticide risks for humans and the environment. The purpose of this paper was to obtain leaching risk maps of the pesticides imidacloprid, lambda-cyhalothrin, and chlorpyrifos in agricultural soil under an onion (Allium cepa L.) crop in Tibasosa, Boyacá, Colombia. This was obtained by studying the soil types in the area, analyzing the behavior of pollutants in the soil profile, using a delay factor and an attenuation factor to finally include GIS allowing visualization of the areas of greater potential risk in the study area.