Removal of nine pesticide residues from water and soil by biosorption coupled with degradation on biosorbent immobilized laccase

Immobilizing white-rot fungi laccase: Toward bio-derived supports as a circular economy approach in organochlorine removal

Despite their high persistence in the environment, organochlorines (OC) are widely used in the pharmaceutical industry, in plastics, and in the manufacture of pesticides, among other applications. These compounds and the byproducts of their decomposition deserve attention and efficient proposals for their treatment. Among sustainable alternatives, the use of ligninolytic enzymes (LEs) from fungi stands out, as these molecules can catalyze the transformation of a wide range of pollutants. Among LEs, laccases (Lac) are known for their efficiency as biocatalysts in the conversion of organic pollutants. Their application in biotechnological processes is possible, but the enzymes are often unstable and difficult to recover after use, driving up costs. Immobilization of enzymes on a matrix (support or solid carrier) allows recovery and stabilization of this catalytic capacity. Agricultural residual biomass is a passive environmental asset. Although underestimated and still treated as an undesirable component, residual biomass can be used as a low-cost adsorbent and as a support for the immobilization of enzymes. In this review, the adsorption capacity and immobilization of fungal Lac on supports made from residual biomass, including compounds such as biochar, for the removal of OC compounds are analyzed and compared with the use of synthetic supports. A qualitative and quantitative comparison of the reported results was made. In this context, the use of peanut shells is highlighted in view of the increasing peanut production worldwide. The linkage of methods with circular economy approaches that can be applied in practice is discussed.

Nanoclays and mineral derivates applied to pesticide water remediation

Although pesticides are vital in agroecosystems to control pests, their indiscriminate use generates innumerable environmental problems daily. Groundwater and surface water networks are the most affected environmental matrices. Since these water basins are mainly used to obtain water for human consumption, it is a challenge to find solutions to pesticide contamination. For these reasons, development of efficient and sustainable remedial technologies is key. Based on their unique properties including high surface area, recyclability, environmental friendliness, tunable surface chemistry and low cost, nanoclays and derived minerals emerged as effective adsorbents towards environmental remediation of pesticides. This study provides a comprehensive review of the use of nanoclays and mineral derivatives as adsorbents for pesticides in water. For this purpose, the characteristics of existing pesticides and general aspects of the relevant clays and minerals are discussed. Furthermore, the study provides insightful discussion on the potential application of nanoclays and their derivatives toward the mitigation of pesticide pollution in the environment. Finally, the outlook and future prospects on nanoclay implications and their environmental implementation are elucidated.

Investigation of the Persistence, Toxicological Effects, and Ecological Issues of S-Triazine Herbicides and Their Biodegradation Using Emerging Technologies: A Review

S-triazines are a group of herbicides that are extensively applied to control broadleaf weeds and grasses in agricultural production. They are mainly taken up through plant roots and are transformed by xylem tissues throughout the plant system. They are highly persistent and have a long half-life in the environment. Due to imprudent use, their toxic residues have enormously increased in the last few years and are frequently detected in food commodities, which causes chronic diseases in humans and mammals. However, for the safety of the environment and the diversity of living organisms, the removal of s-triazine herbicides has received widespread attention. In this review, the degradation of s-triazine herbicides and their intermediates by indigenous microbial species, genes, enzymes, plants, and nanoparticles are systematically investigated. The hydrolytic degradation of substituents on the s-triazine ring is catalyzed by enzymes from the amidohydrolase superfamily and yields cyanuric acid as an intermediate. Cyanuric acid is further metabolized into ammonia and carbon dioxide. Microbial-free cells efficiently degrade s-triazine herbicides in laboratory as well as field trials. Additionally, the combinatorial approach of nanomaterials with indigenous microbes has vast potential and considered sustainable for removing toxic residues in the agroecosystem. Due to their smaller size and unique properties, they are equally distributed in sediments, soil, water bodies, and even small crevices. Finally, this paper highlights the implementation of bioinformatics and molecular tools, which provide a myriad of new methods to monitor the biodegradation of s-triazine herbicides and help to identify the diverse number of microbial communities that actively participate in the biodegradation process.

Efficient removal of pharmaceutical contaminants from water and wastewater using immobilized laccase on activated carbon derived from pomegranate peels

In this study, pomegranate peels (PPs) as an abundant fruit processing waste was used to produce cost-effective, eco-friendly, and high-quality activated carbon. The produced carbon (fossil free activated carbon) was used for immobilizing laccase to remove a range of emerging pollutants namely diclofenac, amoxicillin, carbamazepine, and ciprofloxacin from water and wastewater. The loaded activated carbon by laccase (LMPPs) and the unloaded one (MPPs) were characterized using advanced surface chemistry analysis techniques. MPPs was found to have a porous structure with a large surface area and an abundance of acidic functional groups. Laccase immobilization reduced surface area but added active degradation sites. The optimal immobilization parameters were determined as pH 4, 35 °C, and a laccase concentration of 2.5 mg/mL resulting in a 69.8% immobilization yield. The adsorption of the emerging pollutant onto MPPs is best characterized as a spontaneous endothermic process that adheres to the Langmuir isotherm and first-order kinetics. Using synergistic adsorption and enzymatic degradation, the target pollutants (50 mg/L) were eliminated in 2 h. In both water types, LMPPs outperformed MPPs. This study shows that pomegranate peels can effectively be harnessed as an enzyme carrier and adsorbent for the removal of emerging pollutants even from a complex sample matrix. The removal of contaminants from wastewater lasted five cycles, whereas it continued up to six cycles for water.

Nitenpyram biodegradation by a novel nitenpyram-degrading bacterium, Ochrobactrum sp. strain DF-1, and its novel degradation pathway

Nitenpyram is a neonicotinoid insecticide that is commonly found in the environment. However, its biodegradation by pure cultures of bacteria has not been widely investigated and the catabolic pathway (s) for nitenpyram metabolism remain elusive. In this study, the aerobic strain DF-1, isolated from a wastewater-treatment pool contaminated with nitenpyram. The strain was designated an Ochrobactrum sp. utilizing a combination of traditional methods and molecular ones. Strain DF-1 can use nitenpyram as a sole carbon or nitrogen source for growth. In liquid medium, 100 mg·L^-1 nitenpyram was metabolized to undetectable levels within 10 days. Four metabolites were found by gas chromatography-mass spectrometry (GC-MS) analyses during nitenpyram degradation. According to the aforementioned data, a partial metabolic pathway of nitenpyram was proposed of strain DF-1. Inoculation of strain DF-1 promoted nitenpyram (10 mg·kg^-1) degradation in either sterile or non-sterile soil. To our knowledge, this is the first characterization of nitenpyram degradation by a specific bacterium and likely to be exploited for the remediation of nitenpyram-contaminated sites.

Magnetically separable laccase-biochar composite enable highly efficient adsorption-degradation of quinolone antibiotics: Immobilization, removal performance and mechanisms

The tremendous potential of hybrid technologies for the elimination of quinolone antibiotics has recently attracted considerable attention. This current work prepared a magnetically modified biochar (MBC) immobilized laccase product named LC-MBC through response surface methodology (RSM), and LC-MBC showed an excellent capacity in the removal of norfloxacin (NOR), enrofloxacin (ENR) and moxifloxacin (MFX) from aqueous solution. The superior pH, thermal, storage and operational stability demonstrated by LC-MBC revealed its potential for sustainable application. The removal efficiencies of LC-MBC in the presence of 1 mM 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) for NOR, ENR and MFX were 93.7 %, 65.4 % and 77.0 % at pH 4 and 40 °C after 48 h reaction, respectively, which were 1.2, 1.3 and 1.3 times higher than those of MBC under the same conditions. The synergistic effect of adsorption by MBC and degradation by laccase dominated the removal of quinolone antibiotics by LC-MBC. Pore-filling, electrostatic, hydrophobic, π-π interactions, surface complexation and hydrogen bonding contributed in the adsorption process. The attacks on the quinolone core and piperazine moiety were involved in the degradation process. This study underscored the possibility of immobilization of laccase on biochar for enhanced remediation of quinolone antibiotics-contaminated wastewater. The proposed physical adsorption-biodegradation system (LC-MBC-ABTS) provided a novel perspective for the efficient and sustainable removal of antibiotics in actual wastewater through combined multi-methods.

Bioremediation potential of laccase for catalysis of glyphosate, isoproturon, lignin, and parathion: Molecular docking, dynamics, and simulation

The present study aimed to investigate the catalytic degradation produced by laccase in the detoxification of glyphosate, isoproturon, lignin polymer, and parathion. We explored laccase-glyphosate, laccase-lignin polymer, laccase-isoproturon, and laccase-parathion using molecular docking (MD) and molecular dynamics simulation (MDS) approaches. The results suggest that laccase interacts well with glyphosate, lignin polymer, isoproturon, and parathion during biodegradation. We calculated the root mean square deviations (RMSD) of laccase-glyphosate, laccase-lignin polymer, laccase-isoproturon, and laccase-parathion as 0.24 ± 0.02, 0.59 ± 0.32, 0.43 ± 0.07, and 0.43 ± 0.06 nm, respectively. In an aqueous solution, the stability of laccase with glyphosate, lignin polymer, isoproturon, and parathion is mediated through the formation of hydrophobic interactions, hydrogen bonds, and van der Waals interactions. The presence of xenobiotic toxic compounds in the active site changed the conformation of laccase. MDS of the laccase-substrate complexes confirmed their stability during catalytic degradation. Laccase assay results confirmed that the degradation of syringol, dihydroconiferyl alcohol, guaiacol, parathion, isoproturon, and glyphosate were 100%, 99.31%, 95.69%, 60.96%, 54.51%, and 48.34% within 2 h, respectively. Taken together, we describe a novel method to understand the molecular-level biodegradation of xenobiotic compounds through laccase and its potential application in contaminant removal.

Investigation of Abortiporus biennis lignocellulolytic toolbox, and the role of laccases in polystyrene degradation

White-rot basidiomycetes are the only microorganisms able to produce both hydrolytic (cellulases and hemicellulases) and oxidative (ligninolytic) enzymes for degrading all lignocellulose constituents. Their enzymatic machinery makes them ideal for the discovery of novel enzymes with desirable properties. In the present work, Abortiporus biennis, a white-rot fungus, was studied in regard to its lignocellulolytic potential. Secretomics and biochemical analyses were employed to study the strain's enzymatic arsenal, after growth in corn stover cultures and xylose-based defined media. The results revealed the presence of all the necessary enzymatic activities for complete breakdown of biomass, while the prominent role of oxidative enzymes in the lignocellulolytic strategy of the strain became evident. Two novel laccases, AbiLac1 and AbiLac2, were isolated from the culture supernatant with ion-exchange chromatography. Characterization of purified laccases revealed their ability to oxidize a wide variety of phenolic and non-phenolic substrates. AbiLac1 was found to oxidize polystyrene powder, showing high depolymerization potential, based on radical chain scission mechanism as evidenced by molecular weight decrease. The results of the present study demonstrate the biotechnological potential of the unexplored enzymatic machinery of white-rot basidiomycetes, including the design of improved lignocellulolytic cocktails, as well as the degradation and/or valorization of plastic waste materials.

Oral administration of Bacillus cereus GW-01 alleviates the accumulation and detrimental effects of β-cypermethrin in mice

Pyrethroid insecticides negatively affect feed conversion, reproductive fitness, and food safety in exposed animals. Although probiotics have previously been widely studied for their effect on gut health, comparatively little is known regarding the efficacy of probiotic administration in specifically reducing pesticide toxicity in mice. We demonstrated that oral administration of a β-cypermethrin (β-CY)-degrading bacterial strain (Bacillus cereus GW-01) to β-CY-exposed mice reduced β-CY levels in the liver, kidney, brain, blood, lipid, and feces (18%-53%). Additionally, co-administration of strain GW-01 to β-CY-exposed mice reduced weight loss (22%-31%) and improved liver function (15%-19%) in mice. Additionally, mice receiving GW-01 had near-control levels of numerous β-CY-affected gut microbial taxa, including Muribaculaceae, Alloprevotella, Bacteroides, Dubosiella, and Alistipes. The survival and β-CY biosorption of GW-01 in simulated gastrointestinal fluid conditions were significantly higher than E. coli. These results suggested that GW-01 can reduce β-CY accumulation and alleviate the damage in mice. This study is the first to demonstrate that a probiotic strain can reduce the toxicity of β-CY in mice.

Phytoremediation potential, antioxidant response, photosynthetic behavior and rhizosphere bacterial community adaptation of tobacco (Nicotiana tabacum L.) in a bisphenol A-contaminated soil

Bisphenol A (BPA) is an emerging organic pollutant, widely distributed and frequently detected in soil in recent years. BPA toxicity is a problem that needs to be solved in terms of both human health and agricultural production. Up to now, the toxic effect of BPA and its mechanism of action on plants, as well as the possibility of using plants to remediate BPA-contaminated soil, remain to be explored. In this study, six treatment groups were set up to evaluate the effects of different concentrations of BPA on the germination and growth of tobacco (Nicotiana tabacum L.) by medium experiments. Furthermore, the representative indexes of photosynthetic and antioxidant system were determined. Meanwhile, tobacco seedlings were cultivated in soil to further explore the effects of BPA on rhizosphere soil enzyme activity and bacterial community structure with or without 100 mg/kg BPA exposure. The enhancement of BPA removal efficiency from soil by phytoremediation using tobacco plants would also be estimated. Our results showed that high doses of BPA in solid medium remarkably inhibited tobacco seedling growth, and its toxicology effect was positively correlated with BPA concentration, while lower BPA exposure (< 20 mg/L) had little limitation on tobacco growth and induced hormesis effect, which was reflected mainly in the increase of root length. In pot experiments, the reducing of chlorophyll content (36.4%) and net photosynthetic rate (41.2%) meant the inhibition of tobacco photosynthetic process due to high concentration of BPA exposure (100 mg/kg) in soil. The increase of H2O2 and O2- content suggested that BPA could destroy the balance of reactive oxygen species (ROS) in plants. However, tobacco plants still presented a high removal efficiency of BPA at the concentration of 100 mg/kg in soil, which could reach to 80% within 30 days. Furthermore, it was indicated that tobacco cultivation changed the structure of rhizosphere soil bacterial communities and the relative abundance of some valuable strains, including Proteobacteria, Acidobacteria and other strains, which might be participated in the BPA removal process. In addition, the tobacco-soil microbial system had the potential to reverse the negative effects caused by BPA through stimulating microorganism associated with soil nutrient cycling. In summary, tobacco is a competitive plant in phytoremediation of BPA-contaminated soil, though the growth of tobacco could be inhibited at high concentration of BPA. Moreover, tobacco might promote the removal efficiency of BPA by regulating the rhizosphere bacteria communities.

Multivariate optimization applied to the synthesis and reuse of a new sugarcane bagasse-based biosorbent to remove Cd(II) and Pb(II) from aqueous solutions

This study reports the use of multivariate tools to optimize the synthesis of a new agricultural-based biosorbent derived from sugarcane bagasse (SB) for the removal of Cd(II) and Pb(II) from aqueous solutions, as well as to optimize the process of desorption of these ions from the spent biosorbent using an acidic solution. The effects of the reaction parameters temperature (T), time (t), and the ratio of 1,2,3,4-butanetetracarboxylic acid dianhydride (BTCAD) to raw SB (w_BTCAD w_raw SB^-1) on the chemical modification of raw SB with BTCAD and on the equilibrium adsorption capacity (q_e) for Cd(II) and Pb(II) were investigated by application of a 2³ Doehlert experimental design (DED), followed by optimization using a statistical desirability tool to produce the best adsorbent in terms of performance and cost. The best reaction condition was w_BTCAD w_raw SB^-1 of 4.0 g g^-1, t of 1 h, and T of 70 ºC. The optimal synthesis condition resulted in a modified sugarcane bagasse (MSB) that provided q_e values for Cd(II) and Pb(II) of 0.50 and 0.61 mmol g^-1, respectively, obtained under the following conditions: 0.311 mmol Cd(II) L^-1, 0.632 mmol Pb(II) L^-1, pH 5.0, 4 h, 0.2 g L^-1 MSB, 130 rpm, and 25 °C. The desorption of Cd(II) and Pb(II) from MSB was investigated by a 2² DED, with optimization using the desirability tool to obtain the best desorption condition in terms of HNO₃ solution concentration ([Formula: see text]) and t. The desorption efficiencies for Cd(II) and Pb(II) were 90 ± 4% and 88 ± 3%, respectively, obtained using 0.7 mol L^-1 HNO₃, t of 42 min, and 1.0 g L^-1 MSB-M(II) (M = Pb or Cd). Infrared spectroscopy was used to investigate the natures of the interactions involved in the adsorption of Cd(II) and Pb(II) on MSB, as well as possible changes in the chemical structure of MSB after desorption. The synthesis of MSB can be performed under mild reaction conditions (t = 1 h, T = 70 ºC), and the solvents used can be recovered by distillation. BTCA is commercially available at moderate cost and can alternatively be obtained employing microbial succinic acid, metal-free catalysis, and modest use of petrochemical feedstocks. Furthermore, MSB can be reused, which could contribute to increasing the economic feasibility of water and wastewater treatment processes.

Toxicological effects, environmental behaviors and remediation technologies of herbicide atrazine in soil and sediment: A comprehensive review

Atrazine has become one of the most popular applied triazine herbicides in the world due to its high herbicidal efficiency and low price. With its large-dosage and long-term use on a global scale, atrazine can cause widespread and persistent contamination of soil and sediment. This review systematically evaluates the toxicological effects, environmental risks, environmental behaviors (adsorption, transport and transformation, and bioaccumulation) of atrazine, and the remediation technologies of atrazine-contaminated soil and sediment. For the adsorption behavior of atrazine on soil and sediment, the organic matter content plays an extremely important role in the adsorption process. Various models and equations such as the multi-media fugacity model and solute transport model are used to analyze the migration and transformation process of atrazine in soil and sediment. It is worth noting that certain transformation products of atrazine in the environment even have stronger toxicity and mobility than its parent. Among various remediation technologies, the combination of microbial remediation and phytoremediation for atrazine-contaminated soil and sediment has wide application prospects. Although other remediation technologies such as advanced oxidation processes (AOPs) can also efficiently remove atrazine from soil, some potential problems still need to be further clarified. Finally, some related challenges and prospects are proposed.

Immobilization of Biomass Materials for Removal of Refractory Organic Pollutants from Wastewater

In the field of environmental science and engineering, microorganisms, enzymes and algae are promising biomass materials that can effectively degrade pollutants. However, problems such as poor environmental adaptability, recycling difficulties, and secondary pollution exist in the practical application of non-immobilized biomass materials. Biomass immobilization is a novel environmental remediation technology that can effectively solve these problems. Compared with non-immobilized biomass, immobilized biomass materials have the advantages of reusability and stability in terms of pH, temperature, handling, and storage. Many researchers have studied immobilization technology (i.e., methods, carriers, and biomass types) and its applications for removing refractory organic pollutants. Based on this, this paper reviews biomass immobilization technology, outlines the mechanisms and factors affecting the removal of refractory organic pollutants, and introduces the application of immobilized biomass materials as fillers for reactors in water purification. This review provides some practical references for the preparation and application of immobilized biomass materials and promotes further research and development to expand the application range of this material for water purification.

Microbially inoculated chars strongly reduce the mobility of alachlor and pentachlorobenzene in an alluvial sediment

The objective of this study was to investigate the transport behavior of two organic and persistent contaminants (alachlor and pentachlorobenzene) on Danube alluvial sediment in the absence and in the presence of microbially inoculated biochar produced at 400 °C and three hydrochars produced at 180, 200, and 220 °C. Stainless steel columns were used for the sorption experiments in nonequilibrium conditions. Obtained results were modeled using the advective-dispersive equation under nonequilibrium conditions. Transport of these compounds through the alluvial sediment column showed that the retention time increased with increasing molecular hydrophobicity. Inoculated biochar increases the retardation of both compounds: twofold for pentachlorobenzene compared with alachlor as a consequence of a higher hydrophobicity. Obtained results indicate that the highest biodegradation coefficient was observed for pentachlorobenzene (λ = 10) in alluvial sediment with addition of an inoculated hydrochar, which is assumed to be a consequence of biosorption. Moreover, all experiments on the columns indicate that the addition of inoculated chars yields a significantly higher R_d coefficient for pentachlorobenzene than for alachlor. Bacterial counts increased in all of the column experiments, which indicates the successful adaptation of microorganisms to experimental conditions and their potential for the removal of a large number of organic pollutants. Thus, addition of inoculated chars to contaminated sediments has the potential as a remediation technique to inhibit the leaching of pollutants to groundwaters. Integr Environ Assess Manag 2022;00:1-10. © 2022 SETAC.

Catalyzed degradation of polycyclic aromatic hydrocarbons by recoverable magnetic chitosan immobilized laccase from Trametes versicolor

The capability of laccase to oxidate a broad range of polyphenols and aromatic substrates in vitro offers a new technological option for the remediation of polycyclic aromatic hydrocarbon (PAH) pollution with high cytotoxicity. However, laccase application in the remediation of PAH-contaminated sites mainly suffers from a low oxidation rate and high cost because of the difficulty in its recovery. In this study, laccases were immobilized on magnetic Fe₃O₄ particles coated with chitosan (Fe₃O₄@SiO₂-chitosan) to improve the operational stability and reusability in the treatment of PAH pollution. The enzyme fixation capacity reached 158 mg g^-1, and 79.1% of free laccase activities were reserved under the optimum immobilized condition of 4% glutaraldehyde, 1.0 mg mL^-1 laccase, 2 h covalent bonding time, and 6 h fixation time. The degradation efficiencies of anthracene (ANT) and benzo[a]pyrene (B(a)P) by Fe₃O₄@SiO₂-chitosan immobilized laccase in 48 h were 81.9% and 69.2%, respectively. Furthermore, it is very easy to magnetically recover the immobilized laccase from reaction systems and reuse it in a new batch. The relative activities of immobilized laccase were over 50% for the degradation of ANT and B(a)P in three catalytic runs, reaching the goal of substantially reducing cost in practice. According to the results from quantum calculations and mass spectrum analyses, the degradation products of ANT and B(a)P by laccase were anthraquinone and B(a)P-dione, respectively. The findings from this study provide valuable insight in promoting the application of immobilized laccase technology in the remediation of PAH contamination.

Tobacco-associated with Methylophilus sp. FP-6 enhances phytoremediation of benzophenone-3 through regulating soil microbial community, increasing photosynthetic capacity and maintaining redox homeostasis of plant

Benzophenone-3 (BP-3) has attracted widespread attention due to its large accumulation in the environment and its potential toxicity effects to human. This study aimed to investigate the effects of the combined application of tobacco and Methylophilus sp. strain FP-6 with both plant growth promoting (PGP) traits and BP-3 degradation function on BP-3 remediation in soil. The results showed that about 79.18% of BP-3 was removed from the soil after 30 days of plant culture inoculated with the FP-6 strain, which was significantly higher than the plant-alone treatment. Simultaneously, inoculation with strain FP-6 significantly improved growth performance, biomass production, antioxidant levels, osmoregulation substance, photosynthetic capacity and chlorophyll accumulation in tobacco. Moreover, the application of FP-6 shifted the bacterial community, and enhanced the abundance of BP-3-degrading or soil nutrient cycling-affecting bacteria (e.g., Chloroflexi, Bryobacter, MND1 and Myxococcales), which might be valuable for the promotion of plant growth and degradation of BP-3 in the soil. The results from this study gave first insights into the enhancement of BP-3 removal efficiency from soil by phytoremediation assisted with bacteria possessing both PGP properties and BP-3 degradation function. The role of soil bacterial community in this remediation process was also discussed.

Green remediation potential of immobilized oxidoreductases to treat halo-organic pollutants persist in wastewater and soil matrices - A way forward

The alarming presence of hazardous halo-organic pollutants in wastewater and soils generated by industrial growth, pharmaceutical and agricultural activities is a major environmental concern that has drawn the attention of scientists. Unfortunately, the application of conventional technologies within hazardous materials remediation processes has radically failed due to their high cost and ineffectiveness. Consequently, the design of innovative and sustainable techniques to remove halo-organic contaminants from wastewater and soils is crucial. Altogether, these aspects have led to the search for safe and efficient alternatives for the treatment of contaminated matrices. In fact, over the last decades, the efficacy of immobilized oxidoreductases has been explored to achieve the removal of halo-organic pollutants from diverse tainted media. Several reports have indicated that these enzymatic constructs possess unique properties, such as high removal rates, improved stability, and excellent reusability, making them promising candidates for green remediation processes. Hence, in this current review, we present an insight of green remediation approaches based on the use of immobilized constructs of phenoloxidases (e.g., laccase and tyrosinase) and peroxidases (e.g., horseradish peroxidase, chloroperoxidase, and manganese peroxidase) for sustainable decontamination of wastewater and soil matrices from halo-organic pollutants, including 2,4-dichlorophenol, 4-chlorophenol, diclofenac, 2-chlorophenol, 2,4,6-trichlorophenol, among others.

Highly hazardous pesticides and related pollutants: Toxicological, regulatory, and analytical aspects

The pervasive manifestation and toxicological influence of hazardous pesticides pose adverse consequences on various environmental matrices and humans, directly via bioaccumulation or indirectly through the food chain. Due to pesticide residues' continuous presence above permissible levels in multiple forms, much attention has been given to re-evaluating to regulate their usage practices without harming or affecting the environment. However, there are regulations in place banning the use of multiple hazardous pesticides in the environment. Thus, efforts must be made to achieve robust detection and complete mitigation of pesticides, possibly through a combination of new and conventional methods. The complex nature of pesticides helps them to react differently across different environmental matrices. Therefore, highly hazardous pesticides are a risk to human well-being and the environment through enzymatic inhibition and the induction of oxidative stress. Consequently, developing fast, sensitive sensing strategies is essential to detect and quantify multiple pesticides and remove the pesticides present in the specific matrix without creating harmful derivatives. Additionally, the technology should be available worldwide to eliminate pesticide residuals from the environment. There are regulations, in practice, that limit the selling, storage, use of pesticides, and their concentration in the environment, although such regulations must be revised. However, the existing literature lacks regulatory, analytical detection, and mitigation considerations for pesticide remediation. Furthermore, the enforcement of such regulations and strict monitoring of pesticides in developing countries are needed. This review spotlights various analytical detection, regulatory, and mitigation considerations for efficiently removing hazardous pesticides.

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.

Recent Developments in the Immobilization of Laccase on Carbonaceous Supports for Environmental Applications - A Critical Review

Τhe ligninolytic enzyme laccase has proved its potential for environmental applications. However, there is no documented industrial application of free laccase due to low stability, poor reusability, and high costs. Immobilization has been considered as a powerful technique to enhance laccase's industrial potential. In this technology, appropriate support selection for laccase immobilization is a crucial step since the support could broadly affect the properties of the resulting catalyst system. Through the last decades, a large variety of inorganic, organic, and composite materials have been used in laccase immobilization. Among them, carbon-based materials have been explored as a support candidate for immobilization, due to their properties such as high porosity, high surface area, the existence of functional groups, and their highly aromatic structure. Carbon-based materials have also been used in culture media as supports, sources of nutrients, and inducers, for laccase production. This study aims to review the recent trends in laccase production, immobilization techniques, and essential support properties for enzyme immobilization. More specifically, this review analyzes and presents the significant benefits of carbon-based materials for their key role in laccase production and immobilization.

Sustainable materials in the removal of pesticides from contaminated water: Perspective on macro to nanoscale cellulose

Recently, over utilization of pesticides in agrarian and non- agrarian sectors has resulted in a significant increment in the deposition of their remnants in different segments of the environmental media. The presence of pesticides and transportation of their different metabolites in rivers, ponds, lakes, soils, air, groundwater sources and drinkable water sources has demonstrated a high threat to human wellbeing and the climate. Thus, the removal of pesticides and their metabolites from contaminated water is imperative to lessen the ill effects of pesticides on human beings. In the present article, we have appraised recent advances in pesticides removal utilizing low cost pristine and functionalized cellulose biomass-based derivatives. One of the key focus has been on better understand the destiny of pesticides in the environment as well as their behaviour in the water. In addition, the impact of magnetite cellulose nanocomposites, cellulose derived photo nano-catalyst, cellulose/clay nano composites, CdS/cellulose nanocomposites and activated carbons/biochar on percent removal of pesticides have also been a part of the current review. The impact of different parameters such as adsorbent dosage, pH, time of contact and initials pesticide concentration on adsorption capacity and adsorption kinetics followed during absorption by different cellulosic bio-adsorbents has also been given. The cellulosic biomass is highly efficient in the removal of pesticides and their efficiency further increases upon functionalization or their conversion into activated carbons forms. Nano particles loaded cellulosic materials have in general found to be less efficient than raw, functionalized cellulosic materials and activated carbons. Further, among different nano particles loaded with cellulose-based materials, cellulose/MnO₂ photonanocatalyst were noticed to be more effective. So considerable efforts should be given to determine the finest practices that relate to the dissipation of different pesticides from the water.

The study of laccase immobilization optimization and stability improvement on CTAB-KOH modified biochar

BACKGROUND

Although laccase has a good catalytic oxidation ability, free laccase shows a poor stability. Enzyme immobilization is a common method to improve enzyme stability and endow the enzyme with reusability. Adsorption is the simplest and common method. Modified biochar has attracted great attention due to its excellent performance.

RESULTS

In this paper, cetyltrimethylammonium bromide (CTAB)-KOH modified biochar (CKMB) was used to immobilize laccase by adsorption method (laccase@CKMB). Based on the results of the single-factor experiments, the optimal loading conditions of laccase@CKMB were studied with the assistance of Design-Expert 12 and response surface methods. The predicted optimal experimental conditions were laccase dosage 1.78 mg/mL, pH 3.1 and 312 K. Under these conditions, the activity recovery of laccase@CKMB was the highest, reaching 61.78%. Then, the CKMB and laccase@CKMB were characterized by TGA, FT-IR, XRD, BET and SEM, and the results showed that laccase could be well immobilized on CKMB, the maximum enzyme loading could reach 57.5 mg/g. Compared to free laccase, the storage and pH stability of laccase@CKMB was improved greatly. The laccase@CKMB retained about 40% of relative activity (4 °C, 30 days) and more than 50% of relative activity at pH 2.0-6.0. In addition, the laccase@CKMB indicated the reusability up to 6 reaction cycles while retaining 45.1% of relative activity. Moreover, the thermal deactivation kinetic studies of laccase@CKMB showed a lower k value (0.00275 min^- 1) and higher t_1/2 values (252.0 min) than the k value (0.00573 min^- 1) and t_1/2 values (121.0 min) of free laccase.

CONCLUSIONS

We explored scientific and reasonable immobilization conditions of laccase@CKMB, and the laccase@CKMB possessed relatively better stabilities, which gave the immobilization of laccase on this cheap and easily available carrier material the possibility of industrial applications.

Effects of different parameters on the removal of atrazine in a water environment by Aspergillus oryzae biosorption

Atrazine is the most extensively used herbicide in the agricultural and forestry sectors. Nevertheless, along with the increasing usage amount of Atrazine, its harm exposed gradually, the main problem is its residues in the environment. Microbial adsorption may effectively reduce the pollution caused by atrazine residue in the environment. In this study, a strain of fungi with the function of adsorbing atrazine was selected using microbial screening technology. According to its phenotypic characteristics and 18S rDNA gene sequencing, this strain was of the species genus Aspergillus and was named ECUST-TXZC2018. By studying the dynamic adsorption effect of this strain on atrazine, we found that this strain adsorbed atrazine after 36 hr at pH=5-7, and 20-30°C with more than 70% adsorption. These results demonstrated that ECUST-TXZC2018 had potential application ability to control atrazine residue pollution through the biosorption function.

Advances in laccase-triggered anabolism for biotechnology applications

This is the first comprehensive overview of laccase-triggered anabolism from fundamental theory to biotechnology applications. Laccase is a typical biological oxidordeuctase that induces the one-electronic transfer of diverse substrates for engendering four phenoxy radicals with concomitant reduction of O₂ into 2H₂O. In vivo, laccase can participate in anabolic processes to create multifarious functional biopolymers such as fungal pigments, plant lignins, and insect cuticles, using mono/polyphenols and their derivatives as enzymatic substrates, and is thus conducive to biological tissue morphogenesis and global carbon storage. Exhilaratingly, fungal laccase has high redox potential (E° = 500-800 mV) and thermodynamic efficiency, making it a remarkable candidate for utilization as a versatile catalyst in the green and circular economy. This review elaborates the anabolic mechanisms of laccase in initiating the polymerization of natural phenolic compounds and their derivatives in vivo via radical-based self/cross-coupling. Information is also presented on laccase immobilization engineering that expands the practical application ranges of laccase in biotechnology by improving the enzymatic catalytic activity, stability, and reuse rate. Particularly, advances in biotechnology applications in vitro through fungal laccase-triggered macromolecular biosynthesis may provide a key research direction beneficial to the rational design of green chemistry.

Risk assessment and the adsorptive removal of some pesticides from synthetic wastewater: a review

Background

The need for environmental protection and remediation processes has been an increasing global concern. Pesticides are used as biological agents, disinfectants, antimicrobials, and also in a mixture of some chemical substances. Their modes of application are through selective dispensing and attenuation processes which act upon any pest that compete with the production, processing, and storage of foods and also in agricultural commodes. The pests might comprise weeds, insects, birds, fish, and microbes.

Main body

Pesticides are commonly found in water surface, landfill leachate, ground water, and wastewater as pollutant. An overview of recently studied adsorption processes for the pesticide elimination from polluted water has been reported in this study utilizing activated carbon, clay materials, biomass materials, metal organic frame work, graphene, and carbon-based materials as well as agricultural wastes as adsorbents. The risk assessment and cost analysis of adsorbents were also provided.

Conclusion

Evidences from literature recommend modified adsorbent and composite materials to have a prospective use in pesticide removal from wastewater. The adsorption data obtained fitted into different isotherm and kinetic models and also the thermodynamic aspect have been discussed.

Graphical abstract

Recent environmental applications of and development prospects for immobilized laccase: a review

Laccases have enormous potential as promising 'green' biocatalysts in environmental applications including wastewater treatment and polluted soil bioremediation. The catalytic oxidation reaction they perform uses only molecular oxygen without other cofactors, and the only product after the reaction is water. The immobilization of laccase offers several improvements such as protected activity and enhanced stability over free laccase. In addition, the reusability of immobilized laccase is adistinct advantage for future applications. This review covers the sources of and progress in laccase research, and discusses the different methodologies of laccase immobilization that have emerged in the recent 5-10 years, as well as its applications to environmental fields, and evaluates these emerging technologies. Abbreviations: (2,4,6-TCP): 2,4,6-trichlorophenol; (2,4-DCP): 2,4-dichlorophenol; (ABTS), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid); (ACE), acetaminophen; (BC-AS), almond shell; (BC-PM), pig manure; (BC-PW), pine wood; (BPA), bisphenol A; (BPA), bisphenol A; (BPF), bisphenol F; (BPS), bisphenol S; (C₆₀), fullerene; (Ca-AIL), calcium-alginate immobilized laccase; (CBZ), carbamazepine; (CETY), cetirizine; (CHT-PGMA-PEI-Cu (II) NPs), Cu (II)-chelated chitosan nanoparticles; (CLEAs), cross-linked enzyme aggregates; (CMMC), carbon-based mesoporous magnetic composites; (COD), chemical oxygen demand; (CPH), ciprofloxacin hydrochloride; (CS), chitosan; (CTC), chlortetracycline; (Cu-AIL), copper-alginate immobilized laccase; (DBR K-4BL), Drimarene brilliant red K-4BL; (DCF), diclofenac; (E1),estrone; (E2), 17 β-estradiol; (EDC), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride; (EDCs), endocrine disrupting chemicals; (EE2), 17α-ethinylestradiol; (EFMs), electrospun fibrous membranes; (FL), free laccase; (fsMP), fumed silica microparticles; (GA-CBs), GLU-crosslinked chitosan beads; (GA-CBs), glutaraldehyde-crosslinked chitosan beads; (GA-Zr-MOF), graphene aerogel-zirconium-metal organic framework; (GLU), glutaraldehyde; (GO), graphene oxide; (HMCs), hollow mesoporous carbon spheres; (HPEI/PES), hyperbranched polyethyleneimine/polyether sulfone; (IC), indigo carmine; (IL), immobilized laccase; (k_cat), catalytic constant; (K_m), Michealis constant; (M-CLEAs), Magnetic cross-linked enzyme aggregates; (MMSNPs-CPTS-IDA-Cu²⁺), Cu²⁺-chelated magnetic mesoporous silica nanoparticles; (MSS), magnetic mesoporous silica spheres; (MWNTs), multi-walled carbon nanotubes; (MWNTs), multi-walled carbon nanotubes; (NHS), N-hydroxy succinimide; (O-MWNTs), oxidized-MWNTs; (P(AAm-NIPA)), poly(acrylamide-N-isopropylacrylamide); (p(GMA)), poly(glycidyl methacrylate); (p(HEMA)), poly(hydroxyethyl methacrylate); (p(HEMA-g-GMA)-NH₂, poly(glycidyl methacrylate) brush grafted poly(hydroxyethyl methacrylate); (PA6/CHIT), polyamide 6/chitosan; (PAC), powdered active carbon; (PAHs), polycyclic aromatic hydrocarbons; (PAM-CTS), chitosan grafted polyacrylamide hydrogel; (PAN/MMT/GO), polyacrylonitrile/montmorillonite/graphene oxide; (PAN/PVdF), polyacrylonitrile/polyvinylidene fluoride; (PEG), poly ethylene glycol; (PEI), Poly(ethyleneimine); (poly(4-VP)), poly(4-vinyl pyridine); (poly(GMA-MAA)), poly(glycidyl methacrylate-methacrylic acid); (PVA), polyvinyl alcohol; (RBBR), Remazol Brilliant Blue R; (SDE), simulated dye effluent; (semi-IPNs), semi-interpenetrating polymer networks; (TC), tetracycline; (TCH), tetracycline hydrochloride; (TCS), triclosan; (Vmax), maximum activity; (Zr-MOF, MMU), micro-mesoporous Zr-metal organic framework.

Hierarchically porous magnetic Fe3O4/Fe-MOF used as an effective platform for enzyme immobilization: a kinetic and thermodynamic study of structure–activity

Fe₃O₄/Fe-MOF integrate magnetic characteristics and hierarchical porous structure for supporting chloroperoxidase (CPO) or horseradish peroxidase (HRP).

Immobilization interaction between xenobiotic and Bjerkandera adusta for the biodegradation of atrazine

The aim of the present work is to evaluate the ability of 'fungi' for the biodegradation of recalcitrant xenobiotic compound, 'Atrazine' in batch liquid cultures. Different parameters like pH (2.0-8.0) temperature (16-32 °C), biomass (1-5 g), and concentration (25-100 ppm) were optimized for the efficient degradation of atrazine. The decomposition behavior of atrazine is analyzed with the help of Fourier Transform Infrared (FTIR) spectroscopy. Herein, we have reported that the Bjerkandera adusta possess high removal efficiency of the xenobiotic compound (atrazine) up to 92%. The fungal strain investigated could prove to be a valuable active pesticide degrading micro-organism, with high detoxification values. These results are useful for improved understanding and prediction of the behavior and fate of B. adusta in the bio-purification of wastewater contaminated with xenobiotics. Thus providing a new and green approach for the remediation of toxicants without altering the environmental components.

Biosorption of tungstate onto garlic peel loaded with Fe(III), Ce(III), and Ti(IV)

In present study, garlic peel (GP) was modified by loading with Fe(III), Ti(IV), and Ce(III) through a cation exchange process, i.e., nGP-COOH + Mn+ = (nGP-COO)-Mn+ + nH+ (M = Fe, Ce, Ti), which could adsorb tungstate effectively under the weakly acidic conditions. The optimal initial pH for maximum adsorption of W(VI) was determined at 1~3 for Ti-GP, 1~4 for Fe-GP, and 3 for Ce-GP, respectively; and at pH 2.5, the corresponding maximum adsorption capacity for Fe-GP, Ti-GP, and Ce-GP was evaluated as 91.5 mg/g, 83 mg/g, and 84 mg/g tungsten respectively. Coexisting anions like chloride, sulfate, and carbonate showed little effect on tungsten adsorption, while fluoride and phosphate inhibited the adsorption drastically. The column adsorption showed that the breakthrough point for Ce-GP, Ti-GP, and Fe-GP was 180 min, 200 min, and 270 min respectively. And 0.1 mol/L NaOH effectively eluted the adsorbed tungsten, and concentration of the eluted solution had almost 6, 19.9, and 22 factors of the initial tungstate concentration correspondingly.

Regulation of surface plasmon resonance and oxygen vacancy defects in chlorine doped Bi–BiO2−x for imidacloprid photocatalytic degradation

In this work, chlorine doped Bi–BiO_2−x (Cl–Bi–BiO_2−x) was prepared by a one-step solvothermal method using sodium bismuthate (NaBiO₃·2H₂O) as a Bi source without the addition of a surfactant.

Applications of Microbial Laccases: Patent Review of the Past Decade (2009–2019)

There is a high number of well characterized, commercially available laccases with different redox potentials and low substrate specificity, which in turn makes them attractive for a vast array of biotechnological applications. Laccases operate as batteries, storing electrons from individual substrate oxidation reactions to reduce molecular oxygen, releasing water as the only by-product. Due to society’s increasing environmental awareness and the global intensification of bio-based economies, the biotechnological industry is also expanding. Enzymes such as laccases are seen as a better alternative for use in the wood, paper, textile, and food industries, and they are being applied as biocatalysts, biosensors, and biofuel cells. Almost 140 years from the first description of laccase, industrial implementations of these enzymes still remain scarce in comparison to their potential, which is mostly due to high production costs and the limited control of the enzymatic reaction side product(s). This review summarizes the laccase applications in the last decade, focusing on the published patents during this period.