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Enzymatic cleavage of C─F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, β-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. The microbial defluorination products were structurally confirmed and showed regiospecificity and stereospecificity, consistent with their formation by enzymatic reactions. A comparison of defluorination activities among several Acetobacterium species indicated that a functional fluoride exporter was required for the detoxification of the released fluoride. Results from both in vivo inhibition tests and in silico enzyme modeling suggested the involvement of enzymes of the flavin-based electron-bifurcating caffeate reduction pathway [caffeoyl-CoA reductase (CarABCDE)] in the reductive defluorination. This is a report on specific microorganisms carrying out enzymatic reductive defluorination of PFAS, which could be linked to electron-bifurcating reductases that are environmentally widespread.

Papiliotrema laurentii 5307AH was isolated from an aircraft polymer-coated surface. The genome size is 19,510,785 bp with a G + C content of 56%. The genome harbors genes encoding oxygenases, cutinases, lipases, and enzymes for styrene degradation, all of which could play a critical role in survival on xenobiotic surfaces.

Given the multitude of extracellular enzymes at their disposal, many of which are designed to degrade natures polymers (lignin, cutin, cellulose, etc.), fungi are adept at targeting synthetic polyesters with similar chemical composition. Microbial-influenced deterioration of xenobiotic polymeric surfaces is an area of interest for material scientists as these are important for the conservation of the underlying structural materials. Here, we describe the isolation and characterization of the Papiliotrema laurentii 5307AH (P. laurentii) cutinase, Plcut1. P. laurentii is basidiomycete yeast with the ability to disperse Impranil-DLN (Impranil), a colloidal polyester polyurethane, in agar plates. To test whether the fungal factor involved in this clearing was a secreted enzyme, we screened the ability of P. laurentii culture supernatants to disperse Impranil. Using size exclusion chromatography (SEC), we isolated fractions that contained Impranil-clearing activity. These fractions harbored a single ~22 kD band, which was excised and subjected to peptide sequencing. Homology searches using the peptide sequences identified, revealed that the protein Papla1 543643 (Plcut1) displays similarities to serine esterase and cutinase family of proteins. Biochemical assays using recombinant Plcut1 confirmed that this enzyme has the capability to hydrolyze Impranil, soluble esterase substrates, and apple cutin. Finally, we confirmed the presence of the Plcut1 in culture supernatants using a custom antibody that specifically recognizes this protein. The work shown here supports a major role for the Plcut1 in the fungal degradation of natural polyesters and xenobiotic polymer surfaces.IMPORTANCEFungi play a vital role in the execution of a broad range of biological processes that drive ecosystem function through production of a diverse arsenal of enzymes. However, the universal reactivity of these enzymes is a current problem for the built environment and the undesired degradation of polymeric materials in protective coatings. Here, we report the identification and characterization of a hydrolase from Papiliotrema laurentii 5307AH, an aircraft-derived fungal isolate found colonizing a biodeteriorated polymer-coated surface. We show that P. laurentii secretes a cutinase capable of hydrolyzing soluble esters as well as ester-based compounds forming solid surface coatings. These findings indicate that this fungus plays a significant role in biodeterioration through the production of a cutinase adept at degrading ester-based polymers, some of which form the backbone of protective surface coatings. The work shown here provides insights into the mechanisms employed by fungi to degrade xenobiotic polymers.

Per- and polyfluoroalkyl substances (PFASs) from aqueous film forming foams (AFFFs) can hinder bioremediation of co-contaminants such as trichloroethene (TCE) and benzene, toluene, ethylbenzene, and xylene (BTEX). Anaerobic dechlorination can require bioaugmentation of Dehalococcoides, and for BTEX, oxygen is often sparged to stimulate in situ aerobic biodegradation. We tested PFAS inhibition to TCE and BTEX bioremediation by exposing an anaerobic TCE-dechlorinating coculture, an aerobic BTEX-degrading enrichment culture, and an anaerobic toluene-degrading enrichment culture to n-dimethyl perfluorohexane sulfonamido amine (AmPr-FHxSA), perfluorohexane sulfonamide (FHxSA), perfluorohexanesulfonic acid (PFHxS), or nonfluorinated surfactant sodium dodecyl sulfate (SDS). The anaerobic TCE-dechlorinating coculture was resistant to individual PFAS exposures but was inhibited by >1000× diluted AFFF. FHxSA and AmPr-FHxSA inhibited the aerobic BTEX-degrading enrichment. The anaerobic toluene-degrading enrichment was not inhibited by AFFF or individual PFASs. Increases in amino acids in the anaerobic TCE-dechlorinating coculture compared to the control indicated stress response, whereas the BTEX culture exhibited lower concentrations of all amino acids upon exposure to most surfactants (both fluorinated and nonfluorinated) compared to the control. These data suggest the main mechanisms of microbial toxicity are related to interactions with cell membrane synthesis as well as protein stress signaling.

The accumulation of microplastics in various ecosystems has now been well documented and recent evidence suggests detrimental effects on various biological processes due to this pollution. Accumulation of microplastics in the natural environment is ultimately due to the chemical nature of widely used petroleum-based plastic polymers, which typically are inaccessible to biological processing. One way to mitigate this crisis is adoption of plastics that biodegrade if released into natural environments. In this work, we generated microplastic particles from a bio-based, biodegradable thermoplastic polyurethane (TPU-FC1) and demonstrated their rapid biodegradation via direct visualization and respirometry. Furthermore, we isolated multiple bacterial strains capable of using TPU-FC1 as a sole carbon source and characterized their depolymerization products. To visualize biodegradation of TPU materials as real-world products, we generated TPU-coated cotton fabric and an injection molded phone case and documented biodegradation by direct visualization and scanning electron microscopy (SEM), both of which indicated clear structural degradation of these materials and significant biofilm formation.

The study aimed to develop a potential biomaterial for neuroregeneration by the electrospinning of the biocompatible polymer polyvinylidene fluoride (PVDF) with innovative functionalized boron nitride quantum dots (F-BNQDs) synthesized via green chemistry using the amino acid taurine as a functionalization. The F-BNQDs were characterized and were found to be 16-21 nm in diameter, showed good photoluminescent characteristics, and their elemental composition was confirmed by x-ray photoelectron spectroscopy, Fourier-transform infrared (FTIR), and ultraviolet spectroscopy. The PVDF with F-BNQDs was prepared at three different concentrations, and the resulting electrospun fibers were characterized by scanning electron microscopy, FTIR, thermogravimetric analysis, contact angle, biodegradation, water uptake, Schwann cell cytotoxicity, and cell behavior studies. The results of the study showed that the addition of F-BNQDs to PVDF resulted in enhanced mechanical properties, decreased contact angle, increased degradability, and water uptake. The lactate dehydrogenase assay revealed that 5% BN-PVDF had the lowest cytotoxicity. Fluroscent 4',6-diamidino-2-phenylindole (DAPI) staining showed that the increase in F-BNQD concentration up to 5% BN-PVDF enhanced cell behavior on the electrospun fibers. Therefore, the study concluded that 5% BN-PVDF would be suitable for further testing as a potential biomaterial for neuroregeneration in vivo. Highlights * Functionalized boron nitride quantum dots (F-BNQDs) were prepared using amino acid taurine. * The F-BNQDs were characterized and electrospun with polyvinylidene fluoride (PVDF). * The incorporation of F-BNQDs to PVDF has enhanced its physicochemical properties. * All samples showed a single [beta]phase PVDF. * Schwann cells showed excellent compatibility and cell adhesion on F-BNQDs/PVDF. KEYWORDS electrospinning, functionalized boron nitride quantum dots, PVDF, Schwann cells, taurine, 1 | INTRODUCTION Peripheral nerve injuries have the potential to cause total transection of the nerve, necessitating surgical intervention to enable the regrowth of axons from the injured site to [...]

[Display omitted] • Biofilters (BFs) can remove significant VMS loads from gas. • Low toluene concentrations (315–635 mg m−3) improved VMS removal. • Majority (87.7%) of VMS and toluene removal occurred in the initial BF section. • Toluene shaped microbial population, boosting VMS-degrading microorganisms. • Results underscore BF potential to reduce VMS concentration, requiring optimization. The removal of volatile methyl siloxanes (VMS) from landfill biogas is crucial for clean energy utilization. VMS are usually found together with aromatic compounds in landfill biogas of which toluene is the major representative. In the present study, two biofilters (BFs) packed with either woodchips and compost (WC) or perlite (PER) were used to study the (co–) removal of octamethyltrisiloxane (L3) and octamethylcyclotetrasiloxane (D4) from gas in presence and absence of toluene, used as a representative aromatic compound. The presence of low inlet toluene concentrations (315 ± 19 – 635 ± 80 mg toluene m-3) enhanced the VMS elimination capacity (EC) in both BFs by a factor of 1.8 to 12.6. The highest removal efficiencies for D4 (57.1 ± 1.1 %; EC = 0.12 ± 0.01 gD4 m-3 h-1) and L3 (52.0 ± 0.6 %; EC = 0.23 ± 0.01 gL3 m-3 h-1) were observed in the BF packed with WC. The first section of the BFs (EBRT = 9 min), where toluene was (almost) completely removed, accounted for the majority (87.7 ± 0.6 %) of the total VMS removal. Microbial analysis revealed the impact of VMS and toluene in the activated sludge, showing a clear selection for certain genera in samples influenced by VMS in the presence (X 2) or absence (X 1) of toluene, such as Pseudomonas (X 1 = 0.91 and X 2 = 12.0 %), Sphingobium (X 1 = 0.09 and X 2 = 4.04 %), Rhodococcus (X 1 = 0.42 and X 2 = 3.91 %), and Bacillus (X 1 = 7.15 and X 2 = 3.84 %). The significant maximum EC values obtained by the BFs (0.58 gVMS m-3 h-1) hold notable significance in a combined system framework as they could enhance the longevity of traditional physicochemical methods to remove VMS like activated carbon in diverse environmental scenarios. [ABSTRACT FROM AUTHOR]

Adhesives are being used ubiquitously, such as automotive, building, electronics, and beyond. Due to the lack of rational design strategies, they have yet to achieve a performance portfolio: mechanically robust, highly adhesive, fire‐retardant, switchable, and sustainable (e.g., biobased, reusable, biodegradable) to ensure their practical applications. Herein, a fire‐retardant phosphorus‐containing pimaric acid bio‐derivative, AD, as functional segments, is rationally engineered to prepare biobased polyurethane (PU) adhesive that realizes such an integrated performance portfolio. Because of dynamic hydrogen‐bonding and π–π stacking of polar AD, the as‐prepared PU adhesive exhibits an ultrahigh adhesion force of 38.8 N cm–1. As‐prepared adhesive can be readily reused benefiting from its good solubility in ethanol and exhibits temperature‐responsive switchable adhesion without degraded adhesion. Also, the adhesive shows intrinsic fire retardance due to its biphasic modes of action. The labile ester bonds in the structure enable the adhesive to completely degrade in the presence of lipase or dilute acid. Further demonstration of its promising applications as an adhesive for nanocomposite heat dissipators shows superior dissipating efficiencies to commercial heat sinks. This work offers a novel design approach for creating next‐generation sustainable high‐performance adhesives with functional integration and circular life cycles, which are anticipated to find extensive real‐world applications. [ABSTRACT FROM AUTHOR]

Dyes can be considered the main contaminants of textile effluents, which have a heterocyclic complicated structure. Disperse dyes are one of the most commonly used classes of dyes with an insoluble nature and low molecular weight. In this study, the elimination of disperse dyes from aqueous medium was investigated by Aspergillus niger fungi using in vivo and in vitro methods. According to the in vitro decolorization results, the fungi showed high biosorption capacity for three different disperse dyes. At an initial dye concentration of 330 mg/l , the adsorption capacity of A. niger measured 225.3 mg/g for Disperse Yellow 23, 127.4 mg/g for Disperse Blue 183, and 176.3 mg/g for Disperse Red 1. Complete dye removal was achieved at lower initial concentrations after a 6-h operation. The results showed that the biosorption process favored acidic conditions, and the adsorption capacity and rate were higher at pH 4.5. Moreover, the kinetics of the adsorption process for all dyes followed the pseudo–second-order kinetic model. An in vivo decolorization test was also performed, in which A. niger was inoculated in a dye-containing medium to investigate the possible biodegradation of the dye by fungi during its growth. The biodegradation process was studied by Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC) methods. The results obtained showed a maximum biodegradation of 49.77% for Disperse Red 1, whereas the decolorization for other dyes was mainly based on biosorption. Practical Applications: The industrial wastewater treatment plans in most dyeing houses consist of preliminary coagulation and flocculation tanks followed by biological wastewater treatment by activated sludge. According to the results of this study, A. niger could be applicable in both wastewater treatment steps in industrial plans. A. niger, as a nonharmful microorganism, could be used as a good adsorbent in the coagulation tanks, replacing the chemical coagulants. The adsorbed dye in A. niger's body mass could easily be separated because of its bulky structure. Because dye removal in this method is nearly complete, the effluent could be used in the same dyeing process without much refining process. Using A. niger in biological aerobic procedures could also be practicable according to the results. A. niger could grow in the aerobic condition of biological tanks and simultaneously degrade and adsorb dye molecules. On the other side, A. niger is commercially used for the production of citric acid, and some enzymes and the body mass produced by these industries could be considered for dye removal processes. The use of A. niger as a biosorbent or degradant for dyes still could be studied in several aspects. The study of the degradation mechanism of different dyes by precise tests like liquid chromatography (LC)-mass is an ongoing study by the current team. Also, using A. niger for real wastewater from dyeing houses and optimizing the dye removal parameters for industrial application is a future research perspective in this case. [ABSTRACT FROM AUTHOR]

The synergistic piezoelectric and osteoconductive properties of barium titanate (BT) and hydroxyapatite (HA) could stir the development of a new generation of synthetic bone graft substitutes, with capability for rapid and safe osseointegration. The research focused on two concurrent approaches for coupling the BT and HA materials: (i) conventional sintering of BT-HA powder mixtures; and (ii) functionalization of pre-sintered BT with HA coatings using magnetron sputtering (MS). Irrespective of the BT/HA ratios ranging from 95/5 to 80/20 wt%, nanocrystalline or highly-crystallized nature of the powders, sub-micron- or micron-sized particle dimensions, and sintering temperature, it was observed that the BT-HA reactivity cannot be prevented above 800 °C. At higher temperatures in the range of 1000–1300 °C, HA undergoes decomposition and extensively reacts with BT, leading to the formation of several secondary phases such as CaTiO 3, Ba 2 Ca(PO 4) 2 , BaCa 6 (PO 4) 4 O, BaCa(PO 3) 4 , and β -Ca 2 P 2 O 7. As a consequence, the cytocompatibility assessed in fibroblast and osteoblast cell cultures, as well as the piezoelectric response, were significantly altered. Applying HA coatings by MS to the sintered BT ceramics successfully preserved their piezoelectric properties, while also providing an unaltered cytocompatible and osteogenic-prone surface. The HA coatings were fully crystallized at post-deposition annealing temperatures of 550 and 700 °C, achieving crystalline qualities comparable to HA powders sintered at 1100 and 1200 °C, respectively. No reactivity events between BT and HA were observed. Partial reactivity was only noticeable upon annealing at 1000 °C. Therefore, it is suggested that the HA coating of BT is effective in seamlessly coupling the piezoelectric and osteogenic properties of the two constituents without compromise. • BT-HA powder mixtures inevitably react at high-temperature to form secondary phases. • The HA osteogenic component can be lost at sintering temperatures above 1000 °C. • The secondary phases lead to a decay of the piezoelectric and biological responses. • HA-magnetron sputtered BT – a feasible solution to overcome inter-phases reactivity. • HA-coated BT yields uncompromised piezoelectric and in-vitro biologic performances. [ABSTRACT FROM AUTHOR]

The current investigation assessed the capability of a well-adapted and enriched bacterial strain known as Bacillus brevis for the biodegradation of phenanthrene. To enhance the removal efficiency of phenanthrene, employed Response Surface Methodology (RSM) in conjunction with a Box-Behnken design (BBD) model. The experiments were designed to explore the impact of pH (6.0 to 9.0), temperature (20 to 40°C), initial phenanthrene concentration (50 and 100 ppm), and incubation time (7 to 21 days) on biodegradation of phenanthrene. The highest level of phenanthrene biodegradation, approximately 55.0%, was achieved by Bacillus brevis when the optimal conditions were met as pH of 7.0, temperature 30oC, and initial phenanthrene concentration (70 ppm) after 21 days of incubation time. This study underscores the significance of employing statistical tools like RSM to enhance the microbial degradation of contaminants. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) has been extensively applied for the production of polycarbonate plastics and epoxy resins, which has gained increasing attention due to its ubiquitous presence and adverse effect on ecosystems and human health. Various biological strategies (such as BPA biodegradation by bacteria, fungi, algae, and plants) have been developed to address BPA contamination issue. This review systematically summarized and analyzed recent advances in biological methods for BPA degradation, including bacterial, fungal, algal, and plants, highlighting the efficiency and mechanisms of BPA degradation. By analyzing the common intermediates of BPA biodegradation by bacteria, fungi, algae and plants reported in previous studies, the typical biodegradation pathways were proposed. The review further addressed the contentious topic of anaerobic BPA degradation, noting the scarcity of definitive evidence endorsing this process. Further, the common enzymes and typical enzymatic reactions involved in the biodegradation process of BPA were summarized. This review will deepen the understanding of BPA biodegradation, leading to the discovery of more efficient microorganisms and highly effective enzymatic catalysts for remediating BPA contamination. [ABSTRACT FROM AUTHOR]

This study aimed to elucidate the potential of Pseudomonas species to degrade furfuryl alcohol (FA), a widely used furanic compound. FA-based resins and biopolymers have applications in various sectors, leading to the gradual discharge of FA into the environment through industrial wastewater. The objective was to find an eco-friendly solution for removing FA residues from industrial effluents, thereby eliminating the hazardous effects of FA. Pseudomonas species have emerged as potential bacterial genera for biodegradation of aromatic compounds; therefore, this study examined the effectiveness of Pseudomonas putida MTCC 1194 and Pseudomonas aeruginosa MTCC 1034 for FA degradation. Significant shifts in the fingerprint regions were observed using Fourier-transform infrared (FTIR) spectroscopy, providing evidence of successful FA degradation. A more than 50% reduction in FA content was observed by both strains, even at high concentrations (500 mgl− 1), as determined by spectrophotometric and high-performance liquid chromatography (HPLC) analysis. Liquid chromatography-mass spectrometry (LC-MS) identified the metabolite as 2-furoic acid (113 m/z). Both bacterial cultures followed substrate inhibition kinetics, and the specific growth rate best fit the Aiba and Haldane models for P. putida and the Haldane and Edwards models for P. aeruginosa. Furthermore, immobilized bacterial cells maintained approximately 50% FA degradation (300 mgl− 1) over five degradation cycles, highlighting their stability and reusability. The phytotoxicity bioassay demonstrated the non-hazardous nature of the metabolites formed after FA biodegradation. These findings underscore the potential of these strains for effective FA bioremediation, paving the way for their use in industrial effluent treatment. [ABSTRACT FROM AUTHOR]

The biocorrosion of a new surgical wire (0.6, 0.8, and 1.0 mm in diameter) obtained from a ZnMg0.004 alloy by hot and cold drawing was characterized using in vitro tests in a bovine animal serum solution and in vivo tests – through placement in the muscles of a rabbit and a in cat's broken paw. Corrosion gravimetric tests were carried out in a corrosive environment refreshed every 3 days and also one which remained unchanged throughout the test period. Electrochemical tests were performed in the same solution of serum as in gravimetric tests. Depending on the initial diameter, complete dissolution of the wire was observed after 36-78 days of immersion in periodically changed serum solution. None of the wires completely dissolved over 120 days in the unreplaced serum solution. The corrosion rate values determined in electrochemical and gravimetric tests were similar. After 90 days of in vivo tests, both in the body of the rabbit and the cat, the degradation of the wire was similar to in vitro tests in the unreplaced serum solution. No harmful effects were observed in the animals. [ABSTRACT FROM AUTHOR]

Acetochlor is a selective pre-emergent herbicide that is widely used to control annual grass and broadleaf weeds. However, due to its stable chemical structure, only a small portion of acetochlor exerts herbicidal activity in agricultural applications, while most of the excess remains on the surfaces of plants or enters ecosystems, such as soil and water bodies, causing harm to the environment and human health. In recent years, researchers have become increasingly focused on the repair of acetochlor residues. Compared with traditional physical and chemical remediation methods, microorganisms are the most effective way to remediate chemical pesticide pollution, such as acetochlor, because of their rich species, wide distribution, and diverse metabolic pathways. To date, researchers have isolated and identified many high-efficiency acetochlor-degrading strains, such as Pseudomonas oleovorans, Klebsiella variicola, Bacillus subtilus, Rhodococcus, and Methylobacillus, among others. The microbial degradation pathways of acetochlor include dechlorination, hydroxylation, N-dealkylation, C-dealkylation, and dehydrogenation. In addition, the microbial enzymes, including hydrolase (ChlH), debutoxylase (Dbo), and monooxygenase (MeaXY), responsible for acetochlor biodegradation are also being investigated. In this paper, we review the migration law of acetochlor in the environment, its toxicity to nontarget organisms, and the main metabolic methods. Moreover, we summarize the latest progress in the research on the microbial catabolism of acetochlor, including the efficient degradation of microbial resources, biodegradation metabolic pathways, and key enzymes for acetochlor degradation. At the end of the article, we highlight the existing problems in the current research on acetochlor biodegradation, provide new ideas for the remediation of acetochlor pollution in the environment, and propose future research directions. [ABSTRACT FROM AUTHOR]

Given environmental persistence, potential for bioaccumulation, and toxicity of Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), the scientific community has increasingly focused on researching their toxicology and degradation methods. This paper presents a survey of recent research advances in the toxicological effects and degradation methods of PFOA and PFOS. Their adverse effects on the liver, nervous system, male reproductive system, genetics, and development are detailed. Additionally, the degradation techniques of PFOA and PFOS, including photochemical, photocatalytic, and electrochemical methods, are analyzed and compared, highlighted the potential of these technologies for environmental remediation. The biotransformation pathways and mechanisms of PFOA and PFOS involving microorganisms, plants, and enzymes are also presented. As the primary green degradation pathway for PFOA and PFOS, Biodegradation uses specific microorganisms, plants or enzymes to remove PFOA and PFOS from the environment through redox reactions, enzyme catalysis and other pathways. Currently, there has been a paucity of research conducted on the biodegradation of PFOA and PFOS. However, this degradation technology is promising owing to its specificity, cost-effectiveness, and ease of implementation. Furthermore, novel materials/methods for PFOA and PFOS degradation are presented in this paper. These novel materials/methods effectively improve the degradation efficiency of PFOA and PFOS and provide new ideas and tools for the degradation of PFOA and PFOS. This information can assist researchers in identifying flaws and gaps in the field, which can facilitate the formulation of innovative research ideas. [ABSTRACT FROM AUTHOR]

Highly acidic citrus pomace (CP) is a byproduct of Pericarpium Citri Reticulatae production and causes significant environmental damage. In this study, a newly isolated acid-tolerant strain of Serratia sp. JS-043 was used to treat CP and evaluate the effect of reduced acid citrus pomace (RACP) in passivating heavy metals. The results showed that biological treatment could remove 97.56% of citric acid in CP, the organic matter in the soil increased by 202.60% and the catalase activity in the soil increased from 0 to 0.117 U g−1. Adding RACP into soil can increase the stabilization of Cu, Zn, As, Co, and Pb. Specifically, through the metabolism of strain JS-043, RACP was also involved in the stabilization of Zn and Pb, and Residual Fraction in the total pool of these metals increased by 10.73% and 10.54%, respectively. Finally, the genome sequence of Serratia sp. JS-043 was completed, and the genetic basis of its acid-resistant and acid-reducing characteristics was preliminarily revealed. JS-043 also contains many genes encoding proteins associated with heavy metal ion tolerance and transport. These findings suggest that JS-043 may be a high-potential strain to improve the quality of acidic organic wastes that can then be useful for soil bioremediation. [ABSTRACT FROM AUTHOR]

Microbial toxicity tests play an important role in various scientific and technical fields including the risk assessment of chemical compounds in the environment. There is a large battery of normalized tests available that have been standardized by ISO (International Organization for Standardization) and OECD (Organization for Economic Co-operation and Development) and which are worldwide accepted and applied. The focus of this review is to provide information on microbial toxicity tests, which are used to elucidate effects in other laboratory tests such as biodegradation tests, and for the prediction of effects in natural and technical aqueous compartments in the environment. The various standardized tests as well as not normalized methods are described and their advantages and disadvantages are discussed. In addition, the sensitivity and usefulness of such tests including a short comparison with other ecotoxicological tests is presented. Moreover, the far-reaching influence of microbial toxicity tests on biodegradation tests is also demonstrated. A new concept of the physiological potential of an inoculum (PPI) consisting of microbial toxicity tests whose results are expressed as a chemical resistance potential (CRP) and the biodegradation adaptation potential (BAP) of an inoculum is described that may be helpful to characterize inocula used for biodegradation tests. Key points: • Microbial toxicity tests standardized by ISO and OECD have large differences in sensitivity and applicability. • Standardized microbial toxicity tests in combination with biodegradability tests open a new way to characterize inocula for biodegradation tests. • Standardized microbial toxicity tests together with ecotoxicity tests can form a very effective toolbox for the characterization of toxic effects of chemicals. [ABSTRACT FROM AUTHOR]

Bioremediation provides an environmentally sound solution for hydrocarbon removal. Although bioremediation under anoxic conditions is slow, it can be coupled with methanogenesis and is suitable for energy recovery. By altering conditions and supplementing alternative terminal electron acceptors to the system to induce syntrophic partners of the methanogens, this process can be enhanced. In this study, we investigated a hydrocarbon-degrading microbial community derived from chronically contaminated soil. Various hydrocarbon mixtures were used during our experiments in the presence of different electron acceptors. In addition, we performed whole metagenome sequencing to identify the main actors of hydrocarbon biodegradation in the samples. Our results showed that the addition of ferric ions or sulphate increased the methane yield. Furthermore, the addition of CO2, ferric ion or sulphate enhanced the biodegradation of alkanes. A significant increase in biodegradation was observed in the presence of ferric ions or sulphate in the case of all aromatic components, while naphthalene and phenanthrene degradation was also enhanced by CO2. Metagenome analysis revealed that Cellulomonas sp. is the most abundant in the presence of alkanes, while Ruminococcus and Faecalibacterium spp. are prevalent in aromatics-supplemented samples. From the recovery of 25 genomes, it was concluded that the main pathway of hydrocarbon activation was fumarate addition in both Cellulomonas, Ruminococcus and Faecalibacterium. Chloroflexota bacteria can utilise the central metabolites of aromatics biodegradation via ATP-independent benzoyl-CoA reduction. Key points: • Methanogenesis and hydrocarbon biodegradation were enhanced by Fe3+ or SO42− • Cellulomonas, Ruminococcus and Faecalibacterium can be candidates for the main hydrocarbon degraders • Chloroflexota bacteria can utilise the central metabolites of aromatics degradation [ABSTRACT FROM AUTHOR]

AbstractLaccase has a wide range of substrates and the oxidation product is water, providing an ideal choice for the biological degradation and decolorization of dyeing wastewater. This study extracted laccase from the fruiting body of Agaricus bisporus, then used o-phthalaldehyde (OPA) as a cross-linking agent and added surface-aminated Fe3O4 nanoparticles (NH2-nanoFe3O4) to prepare magnetic cross-link enzyme aggregates (MCLEAs) of laccase, which was characterized by scanning electron microscope and vibrating sample magnetometer. The optimal temperature for the catalytic reaction of the MCLEAs was 35 °C, and the optimal pH was 3.0. The stability to temperature pH and storage stability were all enhanced. The immobilized laccase was utilized to treat amido black 10B solution, and the decolorization rate reached 92.48%. After five cycles of use, the MCLEAs of laccase could maintain 42.91% of the relative activity and 32.31% of the relative degradation ability to amido black 10B. [ABSTRACT FROM AUTHOR]

A study was conducted to identify the effects of aging on the biodegradability of vermicomposts in soil. Two solid wastes, including cow manure (CM) and wheat residues (WR), were subjected to the vermicomposting. The products of the various ages were mixed with Lavark and Langroud soils and incubated for 45 days. Results indicated that the aging effects led to an increase in the lignin (LG) content. Potentially, mineralizable C was decreased from 5308 mg C kg−1 for fresh substrates to 1643 mg C kg−1 for aged CM vermicompost in the Lavark soil. The decreasing trend was also observed for the Langroud soil. Similar behavior was also shown for the soils when treated with WR vermicomposts of different ages. The age of vermicomposts was negatively correlated with potentially mineralizable C as well as LG and C/N ratio. Multiphase decomposition was observed, in particular when the products of the early ages were used. The aging of CM and WR induced a decrease in the number of decomposition phases. Overall, by aging, the less biodegradable fraction (lignin) accumulates, and the patterns of decomposition tend to decrease the number of decomposition phases or decrease the last phase biodegradation rate constant. [ABSTRACT FROM AUTHOR]

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been widely used around the world in both agricultural and non-agricultural fields due to its high activity. However, the heavy use of 2,4-D has resulted in serious environmental contamination, posing a significant risk to non-target organisms, including human beings. This has raised substantial concerns regarding its impact. In addition to agricultural use, accidental spills of 2,4-D can pose serious threats to human health and the ecosystem, emphasizing the importance of prompt pollution remediation. A variety of technologies have been developed to remove 2,4-D residues from the environment, such as incineration, adsorption, ozonation, photodegradation, the photo-Fenton process, and microbial degradation. Compared with traditional physical and chemical remediation methods, microorganisms are the most effective way to remediate 2,4-D pollution because of their rich species, wide distribution, and diverse metabolic pathways. Numerous studies demonstrate that the degradation of 2,4-D in the environment is primarily driven by enzymatic processes carried out by soil microorganisms. To date, a number of bacterial and fungal strains associated with 2,4-D biodegradation have been isolated, such as Sphingomonas, Pseudomonas, Cupriavidus, Achromobacter, Ochrobactrum, Mortierella, and Umbelopsis. Moreover, several key enzymes and genes responsible for 2,4-D biodegradation are also being identified. However, further in-depth research based on multi-omics is needed to elaborate their role in the evolution of novel catabolic pathways and the microbial degradation of 2,4-D. Here, this review provides a comprehensive analysis of recent progress on elucidating the degradation mechanisms of the herbicide 2,4-D, including the microbial strains responsible for its degradation, the enzymes participating in its degradation, and the associated genetic components. Furthermore, it explores the complex biochemical pathways and molecular mechanisms involved in the biodegradation of 2,4-D. In addition, molecular docking techniques are employed to identify crucial amino acids within an alpha-ketoglutarate-dependent 2,4-D dioxygenase that interacts with 2,4-D, thereby offering valuable insights that can inform the development of effective strategies for the biological remediation of this herbicide. [ABSTRACT FROM AUTHOR]

The present work describes the synthesis of poly(butylene succinate) (PBSu)-cutin copolymers by the two-stage melt polycondensation method, esterification and polycondensation. Cutin was added in four different concentrations, 2.5, 5, 10, and 20 wt%, in respect to succinic acid. The obtained copolymers were studied using a variety of techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), polarized light microscopy (PLM), as well as diffuse reflectance spectroscopy (DRS). A series of results, in agreement between different techniques, revealed the formation of PBSu-cutin interactions, confirming indirectly the successful in situ synthetic route of copolymers. DSC and XRD combined with PLM results provided indications that the crystallization temperature increases with the addition of small amounts of cutin and gradually decreases with increasing concentration. The crystallization process was easier and faster at 2.5%, 5%, and 10% concentrations, whereas at 20%, it was comparable to neat PBSu. The presence of cutin, in general, leads to the facilitated crystallizability of PBSu (direct effect), whereas a moderate drop in the glass transition temperature is recorded, the latter being an indirect effect of cutin via crystallization. The thermal stability improved in the copolymers compared to neat PBSu. Water contact angle measurements confirmed that the addition of cutin decreased the hydrophilicity. The local and segmental relaxation mapping is demonstrated for PBSu/cutin here for the first time. Enzymatic hydrolysis and soil degradation tests showed that, overall, cutin accelerated the decomposition of the polymers. The copolymers may be proven useful in several applications. [ABSTRACT FROM AUTHOR]

Biodegradable biobased polymers derived from biomass (such as plant, animal, marine, or forestry material) show promise in replacing conventional petrochemical polymers. Research and development have been conducted for decades on potential biodegradable biobased polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and succinate polymers. These materials have been evaluated for practicality, cost, and production capabilities as limiting factors in commercialization; however, challenges, such as the environmental limitations on the biodegradation rates for biodegradable biobased polymer, need to be addressed. This review provides a history and overview of the current development in the synthesis process and properties of biodegradable biobased polymers, along with a techno-commercial analysis and discussion on the environmental impacts of biodegradable biobased polymers. Specifically, the techno-commercial analysis focuses on the commercial potential, financial assessment, and life-cycle assessment of these materials, as well as government initiatives to facilitate the transition towards biodegradable biobased polymers. Lastly, the environmental assessment focuses on the current challenges with biodegradation and methods of improving the recycling process and reusability of biodegradable biobased polymers. [ABSTRACT FROM AUTHOR]

Polyacrylamide (PAM) is a high-molecular-weight polymer with extensive applications. However, the inefficient natural degradation of PAM results in environmental accumulation of the polymer. Biodegradation is an environmentally friendly approach in the field of PAM treatment. The first phase of PAM biodegradation is the deamination of PAM, forming the product poly(acrylic acid) (PAA). The second phase of PAM biodegradation involves the cleavage of PAA into small molecules, which is a crucial step in the degradation pathway of PAM. However, the enzyme that catalyzes the degradation of PAA and the molecular mechanism remain unclear. Here, a novel monooxygenase PCX02514 is identified as the key enzyme for PAA degradation. Through biochemical experiments, the monooxygenase PCX02514 oxidizes PAA with the participation of NADPH, causing the cleavage of carbon chains and a decrease in the molecular weight of PAA. In addition, the crystal structure of the monooxygenase PCX02514 is solved at a resolution of 1.97 Å. The active pocket is in a long cavity that extends from the C-terminus of the TIM barrel to the protein surface and exhibits positive electrostatic potential, thereby causing the migration of oxygen-negative ions into the active pocket and facilitating the reaction between the substrates and monooxygenase PCX02514. Moreover, Arg10-Arg125-Ser186-Arg187-His253 are proposed as potential active sites in monooxygenase PCX02514. Our research characterizes the molecular mechanism of this monooxygenase, providing a theoretical basis and valuable tools for PAM bioremediation. [ABSTRACT FROM AUTHOR]

Synthetic dyes pose a significant environmental threat due to their complex structures and resistance to microbial degradation. S. commune 15R-5-F01 exhibited over 96% degradation efficiency of Methyl Red in a medium with 100 mg L−1 Methyl Red within 3 h. The fungus demonstrated adaptability to various environmental conditions, including different pH levels, temperatures, oxygen concentrations, salinity, and heavy metals. S. commune 15R-5-F01 is capable of achieving repeated cycles of Methyl Red reduction with sustained degradation duration minimum of 6 cycles. It showed a maximum Methyl Red biodegradation capacity of at least 558 mg g−1 dry mycelia and a bioadsorption capacity of 57 mg g−1. Gas chromatography–mass spectrometry analysis confirmed the azo reduction of Methyl Red into N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Enzymatic activity assays indicated the involvement of lignin peroxidases, laccases, and manganese peroxidase in the biodegradation process. Phytotoxicity tests on Triticum eastivum, Oryza sativa, and Vigna umbellata seeds revealed reduced toxicity of the degradation products compared to Methyl Red. This study identifies S. commune 15R-5-F01 as a viable candidate for the sustainable degradation of synthetic dyes in industrial wastewater. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the biodegradation behaviour of starch/nanocellulose/black tea extract (SNBTE) films in a 30-day soil burial test. The SNBTE films were prepared by mixing commercial starch, nanocellulose (2, 4, and 6%), and an aqueous solution of black tea extract by a simple mixing and casting process. The chemical and morphological properties of the SNBTE films before and after biodegradation were characterized using the following analytical techniques such as field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and fourier transform infrared (FTIR). The changes in soil composition, namely pH, electrical conductivity (EC), moisture content, water holding capacity (WHC), soil respiration, total nitrogen, weight mean diameter (MDW), and geometric mean diameter (GMD), as a result of the biodegradation process, were also estimated. The results showed that the films exhibited considerable biodegradability (35–67%) within 30 days while increasing soil nutrients. The addition of black tea extract reduced the biodegradation rate due to its polyphenol content, which likely resulted in a reduction in microbial activity. The addition of nanocellulose (2–6% weight of starch) increased the tensile strength, but decreased the elongation at break of the films. These results suggest that starch nanocellulose and SNBTE films are not only biodegradable under soil conditions but also positively contribute to soil health, highlighting their potential as an environmentally friendly alternative to traditional plastic films in the packaging industry. [ABSTRACT FROM AUTHOR]

This research used end-of-use cotton apparel to develop mulch mats, a type of agrotextiles. The researchers collected and sorted end-of-use garments to obtain cotton textile waste. These end-of-use garments were deconstructed to obtain shredded textiles and big pieces of textiles. Using the textiles from deconstructed end-of-use garments, together with a small amount of new cotton fibers, the researchers used a Feltloom to develop needle-punched nonwoven fabrics that can be used as mulch mats. The researchers tested textile properties of these mulch mats and conducted agricultural field tests for weed control and pot tests for biodegradation. The researchers also tested the mulch mats' soil moisture infiltration, and impact on water evaporation. The nonwoven mulch mats made from end-of-use garments have excellent weed inhibition capability and biodegradability. Compared to plastic mulch sheet, the nonwoven mulch mats are better for water utilization in rainfall watering and sprinkle irrigation but poorer in water conservation in drip irrigation. Considering durability, biodegradability, and soil temperature regulation, it is recommended to use 100% cotton and felt four times to produce mulch mats from end-of-use garments. [ABSTRACT FROM AUTHOR]

This study is aimed at determining the biodegradation potential of n-hexadecane by three bacterial strains (Pseudomonas aeruginosa, Bacillus subtilis, and Bacillus Paralicheniformis) isolated from seawater contaminated with petroleum. The effects of parameters, including the surfactant (Tween 20, Tween 80, and sodium dodecyl sulfate (SDS)), concentration (1-4 CMC (critical micelle concentration)), n-hexadecane concentration (0.5-5%), and bacterial consortium volume (5-20 mL), were investigated on the biodegradation of n-hexadecane. Finally, intermediate compounds resulting from the biodegradation of n-hexadecane were determined. Based on the results, the highest biodegradation of n-hexadecane (80.34%) was obtained in Tween 80 surfactant after 21 days compared to SDS (46.17%) and Tween 20 (72.97%) surfactants. The lowest and highest biodegradation of n-hexadecane (%) at the end of day 21 was obtained at concentrations of 1 (80.14%) and 4 (90.82%) CMC of Tween 80 surfactant, respectively. The biodegradation of n-hexadecane (%) significantly increased (98.8%) at the end of 21 days when the bacterial consortium was utilized in high volume (20 mL). The highest biodegradation of n-hexadecane (%) occurred at a concentration of 0.5% and reached 99.12% after 70 days. In addition, the Pseudomonas aeruginosa strain biodegraded n-hexadecane better after 21 days (25.15%) compared to Bacillus subtilis (20.5%) and Bacillus Paralicheniformis (16.8%). Biodegradation of n-hexadecane by these bacteria produced n-tridecane-1-ol, 2-hexadecanol, n-hexadecanoic acid, and 1-hexadecanol as intermediates. The results indicated that the synergy of bacterial consortium and surfactant could improve the biodegradation of n-hexadecane. [ABSTRACT FROM AUTHOR]

Electrochemical-assisted microbial degradation technology was considered a crucial strategy to reduce micropollutants, but the mechanism of the pulsed electric field (PEF) in affecting biodegradation had not been systematically studied. This study aimed to construct a bio-electrochemical system (BES) using PEF to investigate its effect on the degradation of triclosan (TCS) by the aerobic bacterium Bacillus sp. DL4. The operating optimal parameters for the BES (i.e. 0.01 A of the pulsed current, 1000 Hz of the pulse frequency, Fe (+)–C (−) of the plate materials, 4 cm of the plate spacing) were obtained by batch experiments. The maximum biomass (OD600 = 1.0 ± 0.05) was achieved and the removal efficiency of TCS reached above 95% in 24 h under the obtained operating conditions. Meanwhile, a thorough and methodical investigation of the metabolites in strain DL4 stimulated by PEF using untargeted Liquid Chromatography – Mass Spectrometry (LC-MS). In multivariate analysis, the experimental groups showed a notable separation in Principal Components Analysis (PCA) and Orthogonal Partial Least Squares Analysis discriminant analysis (OPLS-DA) score plots. A total of 3181 differential metabolites were obtained, and the up-regulated metabolites were mainly related to 'Aminoacyl-tRNA biosynthesis', 'Arginine and proline metabolism', 'Lysine degradation', 'ABC transporters', and 'TCA cycle', implying that PEF enhanced the degradation efficiency of TCS by enriching functional genes with transport ability and ion migration ability in cells. This study illuminated how PEF can affect TCS biodegradation and gives insights into the application prospect of electrochemical-assisted biodegradation technology in water environment treatment. [ABSTRACT FROM AUTHOR]

Abdominal aortic aneurysm (AAA) is a life-threatening vascular disease, while there is a lack of pharmaceutical interventions to halt AAA progression presently. To address the multifaceted pathology of AAA, this work develops a novel multifunctional gene delivery system to simultaneously deliver two siRNAs targeting MMP-2 and MMP-9. The system (TPNs-siRNA), formed through the oxidative polymerization and self-assembly of epigallocatechin gallate (EGCG), efficiently encapsulates siRNAs during self-assembly. TPNs-siRNA safeguards siRNAs from biological degradation, facilitates intracellular siRNA transfection, promotes lysosomal escape, and releases siRNAs to silence MMP-2 and MMP-9. Additionally, TPNs, serving as a multi-bioactive material, mitigates oxidative stress and inflammation, fosters M1-to-M2 repolarization of macrophages, and inhibits cell calcification and apoptosis. In experiments with AAA mice, TPNs-siRNA accumulated and persisted in aneurysmal tissue after intravenous delivery, demonstrating that TPNs-siRNA can be significantly distributed in macrophages and VSMCs relevant to AAA pathogenesis. Leveraging the carrier's intrinsic multi-bioactive properties, the targeted siRNA delivery by TPNs exhibits a synergistic effect for enhanced AAA therapy. Furthermore, TPNs-siRNA is gradually metabolized and excreted from the body, resulting in excellent biocompatibility. Consequently, TPNs emerges as a promising multi-bioactive nanotherapy and a targeted delivery nanocarrier for effective AAA therapy. [ABSTRACT FROM AUTHOR]

This review explores the hidden hazards associated with the reuse of treated wastewater and sewage sludge in agriculture while proposing mitigation strategies. It examines the origins and pathways of microplastics (MPs) in wastewater treatment plants and how these pollutants infiltrate agricultural ecosystems. The review assesses the effectiveness of MP removal from wastewater and its fate in soil after reuse, highlighting contamination dynamics and the need for proactive measures. Introducing soil remediation methods is crucial for addressing this issue. Alarming evidence of MPs in human blood, testis, semen, and placenta underscores the urgency for solutions, revealing significant threats to human health, particularly reproductive health. The review advocates for sustainable agricultural practices and effective soil remediation strategies to mitigate MP contamination, promoting environmental preservation, food safety, and human health protection. [ABSTRACT FROM AUTHOR]

The widespread use of polymers has made our lives increasingly convenient by offering a more convenient and dependable material. However, the challenge of efficiently decomposing these materials has resulted in a surge of polymer waste, posing environment and health risk. Currently, landfill and incineration treatment approaches have notable shortcomings, prompting a shift towards more eco-friendly and sustainable biodegradation approaches. Biodegradation primarily relies on microorganisms, with research focusing on both solitary bacterial strain and multi-strain communities for polymer biodegradation. Furthermore, directed evolution and rational design of enzyme have significantly contributed to the polymer biodegradation process. However, previous reviews often undervaluing the role of multi-strain communities. In this review, we assess the current state of these three significant fields of research, provide practical solutions to issues with polymer biodegradation, and outline potential future directions for the subject. Ultimately, biodegradation, whether facilitated by single bacteria, multi-strain communities, or engineered enzymes, now represents the most effective method for managing waste polymers. [ABSTRACT FROM AUTHOR]

The degradation of tilmicosin (TLM), a semi-synthetic 16-membered macrolide antibiotic, has been receiving increasing attention. Conventionally, there are three tilmicosin degradation methods, and among them microbial degradation is considered the best due to its high efficiency, eco-friendliness, and low cost. Coincidently, we found a new strain, Glutamicibacter nicotianae sp. AT6, capable of degrading high-concentration TLM at 100 mg/L with a 97% removal efficiency. The role of tryptone was as well investigated, and the results revealed that the loading of tryptone had a significant influence on TLM removals. The toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic substances. Based on the identified intermediates, the degradation of TLM by AT6 processing through two distinct pathways was then proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

• A large percentage of plastic is abandoned in the environment, reaching rivers and thus the sea. • Bioplastics have been introduced with the aim of partially replacing plastics and reduce pollution. • Test methods fail to establish a value for parameters to be met to define a substance as biodegradable. • Although biodegradable bioplastics are largely perceived to be a biodegradable material, a large amount is characterised by a widely varied degree of biodegradability. • The authors suggest including ecotoxic analysis of by-products in the presence of incomplete biodegradation. Bioplastics were first introduced as environmentally friendly materials, with properties similar to those of conventional plastics. A bioplastic is defined as biodegradable if it can be decomposed into carbon dioxide under aerobic degradation, or methane and CO 2 under anaerobic conditions, inorganic compounds, and new cellular biomass, by the action of naturally occurring microorganisms. This definition however does not provide any information on the environmental conditions, timescale and extent at which decomposition processes should occur. With regard to the aquatic environment, recognized standards have been established to assess the ability of plastics to undergo biodegradation; however, these standards fail to provide clear targets to be met to allow labelling of a bioplastic as biodegradable. Moreover, these standards grant the user an extensive leeway in the choice of process parameters. For these reasons, the comparison of results deriving from different studies is challenging. The authors analysed and discussed the degree of biodegradability of a series of biodegradable bioplastics in aquatic environments (both fresh and salt water) using the results obtained in the laboratory and from on-site testing in the context of different research studies. Biochemical Oxygen Demand (BOD), CO 2 evolution, surface erosion and weight loss were the main parameters used by researchers to describe the percentage of biodegradation. The results showed a large variability both in weight loss and BOD, even when evaluating the same type of bioplastics. This confirms the need for a reference range of values to be established with regard to parameters applied in defining the biodegradability of bioplastics. [Display omitted] [ABSTRACT FROM AUTHOR]

Transcatheter aortic valve implantation (TAVI) was initially developed for adult patients, but there is a growing interest to expand this procedure to younger individuals with longer life expectancies. However, the gradual degradation of biological valve leaflets in transcatheter heart valves (THV) presents significant challenges for this extension. This study aimed to establish a multiphysics computational framework to analyze structural and flow measurements of TAVI and evaluate the integration of optical fiber and photoplethysmography (PPG) sensors for monitoring valve function. A two-way fluid–solid interaction (FSI) analysis was performed on an idealized aortic vessel before and after the virtual deployment of the SAPIEN 3 Ultra (S3) THV. Subsequently, an analytical analysis was conducted to estimate the PPG signal using computational flow predictions and to analyze the effect of different pressure gradients and distances between PPG sensors. Circumferential strain estimates from the embedded optical fiber in the FSI model were highest in the sinus of Valsalva; however, the optimal fiber positioning was found to be distal to the sino-tubular junction to minimize bending effects. The findings also demonstrated that positioning PPG sensors both upstream and downstream of the bioprosthesis can be used to effectively assess the pressure gradient across the valve. We concluded that computational modeling allows sensor design to quantify vessel wall strain and pressure gradients across valve leaflets, with the ultimate goal of developing low-cost monitoring systems for detecting valve deterioration. [ABSTRACT FROM AUTHOR]

In the modern era of human progress and industrialization, various agricultural and industrial activities lead to the accumulation of excessive hazardous substances in the environment. These wastes are continuously being concentrated in agricultural soil or water, thereby affecting and threatening the lives of both flora and fauna. To treat these toxic substances, various physico-chemical practices are performed, which are ultimately associated with the production of other toxic chemicals in the environment. Some of the toxic products formed are recalcitrant and inert which further causes hindrances in the proper removal of contaminants from different pollutant sites. However, various biological approaches are being used nowadays for the remediation of these pollutants from the environment. Microbial bioremediation and phytoremediation represent such environment-friendly approaches that have been employed in the degradation of many of these chemicals. Among the microbes, endophytes are now considered a promising means of the remediation of different pollutants from their natural environments. Therefore, the review focuses on the use of endophytes in the treatment of different kinds of pollutants and highlights the potential of these microbial tools in the removal of heavy metals, plastic, and other contaminants from both terrestrial and aquatic habitats. [ABSTRACT FROM AUTHOR]

Lubricant oils are largely responsible for environmental contamination and surfactants can hopefully improve the bioremediation process in soils contaminated with this kind of waste. However, to date only a few studies have elucidated how different surfactants affect the bioremediation process in oil-contaminated soils using the bioaugmentation technique. Thus, this study aimed to compare the effects of surfactants on the bioremediation process of waste lubricant oil in soil in association or not with bioaugmentation. Three biostimulating agents were tested: a chemical detergent, a synthetic surfactant, and a biosurfactant (rhamnolipid). The bioaugmentation process with Pseudomonas aeruginosa showed a faster biodegradation activity with total biodegradation on 181 day after application. The biosurfactant increased the number of microbial and fungal colonies leading to high biodegradation levels and a quicker treatment with or without the bioaugmentation. Bioaugmentation associated with biosurfactant reached 30.43 mg of CO2 of production on 181 day (90% of total biodegradation of waste lubricant oil) and reduced soil toxicity to 30%. Therefore, results showed that the association of biosurfactant and bioaugmentation with P. aeruginosa represents an ecologically viable strategy for bioremediation of soils contaminated with waste lubricant oil. [ABSTRACT FROM AUTHOR]

Plant fibers' wide availability and accessibility are the main causes of the growing interest in sustainable technologies. The two primary factors to consider while concentrating on composite materials are their low weight and highly specific features, as well as their environmental friendliness. Pineapple leaf fiber (PALF) stands out among natural fibers due to its rich cellulose content, cost-effectiveness, eco-friendliness, and good fiber strength. This review provides an intensive assessment of the surface treatment, extraction, characterization, modifications and progress, mechanical properties, and potential applications of PALF-based polymer composites. Classification of natural fibers, synthetic fibers, chemical composition, micro cellulose, nanocellulose, and cellulose-based polymer composite applications have been extensively reviewed and reported. Besides, the reviewed PALF can be extracted into natural fiber cellulose and lignin can be used as reinforcement for the development of polymer biocomposites with desirable properties. Furthermore, this review article is keen to study the biodegradation of natural fibers, lignocellulosic biopolymers, and biocomposites in soil and ocean environments. Through an evaluation of the existing literature, this review provides a detailed summary of PALF-based polymer composite material as suitable for various industrial applications, including energy generation, storage, conversion, and mulching films. [ABSTRACT FROM AUTHOR]

Ochratoxin A (OTA) is a mycotoxin mainly produced by Aspergillus section Circumdati and section Nigri across the coffee chain. OTA is nephrotoxic and is a threat to human health. This review summarizes current knowledge on how to reduce OTA concentration in coffee from farm to cup. After a brief introduction to the OTA occurrence in coffee, current good management practices are introduced. The core of this review focuses on biocontrol and microbial decontamination by lactic acid bacteria, yeasts and fungi, and their associated enzymes currently reported in the literature. Special attention is given to publications closest to in vivo applications of biocontrol agents and microbial OTA adsorption or degradation agents. Finally, this review provides an opinion on which future techniques to promote within the coffee supply chain. [ABSTRACT FROM AUTHOR]

In all variants where carbon felt was present, imidacloprid degradation by the microflora of bottom sediments was many times higher than in the control, reaching 84.0 ± 1.7% under the polar connection of an external voltage source (1.2 V). When Shewanella oneidensis MR-1 was introduced, almost complete degradation of the pollutant was observed, while in the control without electrodes, it was 29.7 ± 6.0%. The relative representation of the genes of the MtrB transmembrane protein of the respiratory chain, which is associated with exoelectrogenesis, depended on the external chain and had a maximum value when the voltage source was connected polarly, correlating with the pesticide degradation by the autochthonous microflora, similar to the DyP-type peroxidase genes. The introduction of S. oneidensis MR-1 resulted in an almost tenfold increase in the relative representation of DyP-type peroxidase genes. In all experimental variants, the values of the DyP relative representation were significantly higher than in the control without carbon felt, as well as the degree of imidacloprid degradation under these experimental conditions. [ABSTRACT FROM AUTHOR]

In the current study, samples were taken from the sewage treatment plant to isolate rubber-degrading microbial strains. The sludge samples were screened for rubber degradation microbes and later on, each strain was separately characterised for rubber degradation. Initially, strain BA23 showed half the rubber degradation ratio in mineral salt medium. The isolated microbial strains were identified based on 16SrRNA gene sequence analysis, morphological and biochemical characteristics and named Brucella sp. belonging to the genus Bacillus. Later on, the medium conditions for strain BA23 were optimised based on carbon, nitrogen sources, pH, temperature and incubation period. After optimising various environmental and nutritional conditions, the rubber degradation increased twice when inorganic nitrogen sources (aammonium nitrate) used 1 g/L in the medium at pH 7.5. Furthermore, the structural changes that occurred in the rubber polymer associated with the rubber polymer were analysed through Fourier transform infrared spectroscopy (FTIR) and the breakdown of important functional groups such as aldehyde, ketone ester and carboxylic acid was observed. Finally, the gravimetric weight loss of CO2 during rubber degradation was 42.88 g/L, showing CO2 evolution greatly when the rubber degradation occurred in the mineral salt medium. It was concluded that strain BA23 has a maximum potential for rubber degradation when it is used for future solid waste management of rubber and its products for a long period in the environment. [ABSTRACT FROM AUTHOR]

Semi-IPN composites of natural rubber (NR), hydrophilic sodium carboxymethyl cellulose (CMC) and carbon black (CB) with different compositions have been created by solution casting process in an attempt to develop a novel adsorbent under various pH ranges for the cationic dye methylene blue (MB). The produced NR/CMC film can be employed as an adsorbent of MB dye, according to the results, which demonstrate that composites with 2% CMC and 0.2 g CB displayed a maximum adsorption capacity of 1.72 mg/g and a dye removal efficiency of 85.22% at pH 9. The semi-IPNs were characterised using X-ray diffraction, Thermogravimetry, FTIR, and SEM methods. The NR/CMC semi-IPN composites' SEM micrographs showed a continuous, homogenous and porous structure. The films' equilibrium swelling characteristics were examined. For the NR98%CMC2% polymeric composition, containing 2% glutaraldehyde (GA) and 0.02 g CB loading, a maximum tensile strength of 3.3 MPa was achieved. In a 12-month period with 2% CMC, the NR/CMC semi-IPN showed a 70% biodegradation rate, while the pure NR showed only a 20% degradation rate. X-ray diffraction analysis shows that the addition of CMC reduces the crystallinity of natural rubber. [ABSTRACT FROM AUTHOR]

Plastics have accumulated in open environments, such as oceans, rivers, and land, for centuries, but their effect has been of concern for only decades. Plastic pollution is a global challenge at the forefront of public awareness worldwide due to its negative effects on ecological systems, animals, human health, and national economies. Therefore, interest has increased regarding specific circular economies for the development of plastic production and the investigation of green technologies for plastic degradation after use on an appropriate timescale. Moreover, biodegradable plastics have been found to contain potential new hazards compared with conventional plastics due to the physicochemical properties of the polymers involved. Recently, plastic biodegradation was defined as microbial conversion using functional microorganisms and their enzymatic systems. This is a promising strategy for depolymerizing organic components into carbon dioxide, methane, water, new biomass, and other higher value bioproducts under both oxic and anoxic conditions. This study reviews microplastic pollution, the negative consequences of plastic use, and the current technologies used for plastic degradation and biodegradation mediated by microorganisms with their drawbacks; in particular, the important and questionable role of extremophilic multi-enzyme-producing bacteria in synergistic systems of plastic decomposition is discussed. This study emphasizes the key points for enhancing the plastic degradation process using extremophiles, such as cell hydrophobicity, amyloid protein, and other relevant factors. Bioprospecting for novel mechanisms with unknown information about the bioproducts produced during the plastic degradation process is also mentioned in this review with the significant goals of CO2 evolution and increasing H2/CH4 production in the future. Based on the potential factors that were analyzed, there may be new ideas for in vitro isolation techniques for unculturable/multiple-enzyme-producing bacteria and extremophiles from various polluted environments. [ABSTRACT FROM AUTHOR]

The drastic increase in the amount of packaging waste from conventional plastics, caused by improper waste management, is a serious challenge for the planet. It is therefore worth considering how we can solve this problem. Thus, it is necessary to develop new polymeric materials that retain the functional properties of traditional plastics but are susceptible to degradation with the participation of microorganisms. The development of new eco-friendly materials requires a holistic approach in terms of their disposal. Organic recycling enables the disposal of biodegradable packaging along with food remains that are difficult to remove. The article presents a study on the degradation of biocomposites of polylactide with cork in various environments (water, buffer, and compost). The obtained results indicate a clear influence of the presence of the filler and its amount on the degradation profile of the composites. In addition, the effect of sample shrinkage was observed, especially during degradation in water, where the pH decreases during the process due to the appearance of degradation products. This effect may be important not only for the degradation profile of the packaging but also during its use. Packaging distorted due to shrinkage may be a sign of improper product storage. [ABSTRACT FROM AUTHOR]

The utilization of biodegradable hydrogels based on natural polysaccharides in the agricultural and biomedical sectors is anticipated to be a growing field of interest. Due to increasing environmental pollution, the current global goal is to synthesize sustainable materials based on natural polysaccharides to conserve natural resources for the future. In this study, we synthesized an amla-based hydrogel, denoted as AL-g-poly(MAA), using the graft-free radical polymerization method. Methacrylic acid (MAA) was employed as the monomer, N,N′-methylenebisacrylamide (MBA) served as the crosslinker, and ammonium persulfate (APS) acted as the initiator. The synthesized hydrogel, AL-g-poly(MAA), underwent optimization by adjusting seven parameters: initiator, solvent, time, monomer, power, pH, and crosslinker, to achieve the highest swelling percentage. The optimized values were as follows: solvent: 10 ml, time: 150 s, monomer: 0.039 mol/L, power: 60%, pH: 7, and crosslinker: 0.0648 mol/L. The cross-linking process was confirmed through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) techniques. The swelling behavior of the synthesized hydrogels was determined in saline solutions with varying ionic strengths and concentrations, revealing maximum swelling in solutions with lower ionic strengths and concentrations. Additionally, the density and porosity of the hydrogels were examined. The biodegradability of AL-g-poly(MAA) was tested through soil burial and vermicomposting experiments, demonstrating its significant potential for agriculture applications. Furthermore, both the backbone and the synthesized hydrogel were evaluated for antibacterial activity against four bacterial strains (Burkholderia gladioli, Klebsiella pneumoniae, Staphylococcus aureus, and Bacillus cereus), revealing strong potential as an antimicrobial agent and therefore having applications in the biomedical field. The mechanism underlying the inhibitory effect of synthesized AL-g-poly(MAA) hydrogel on bacterial cell membranes is also discussed. [ABSTRACT FROM AUTHOR]

Starch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix. [ABSTRACT FROM AUTHOR]

Biological activity, climate and pollution are responsible for the degradation of building stones, especially limestone, which is widely used in the Paris region. In order to determine the respective contribution of physicochemical and biological processes to the degradation of limestone, limestone specimens from the Père-Lachaise cemetery (Paris, France) were exposed for five years under different conditions: sheltered from or exposed to rain and in horizontal or vertical position. After exposure, the collected samples were characterized by light and electron microscopy, X-Ray diffraction and ion chromatography after elution. The results showed an intense biocolonization of the samples exposed to rain, while the sheltered samples were more affected by the pollution (soiling). The characterization of the bacterial and fungal communities using Next Generation Sequencing Illumina 16S for bacteria and ITS for fungi highlighted that five main bacterial phyla were identified: Actinobacteriota, Bacteroidota, Cyanobacteria, Proteobacteria and Deinococcota (major genera Flavobacterium, Methylobacterium-Methylobacter, Sphingomonas, Roseomonas and Nocardiodes). Among the fungi, the phylum Ascomycota was predominant with the genera Cladosporium, Ramularia, Aureobasidium and Lecania. However, the alteration of the limestone is difficult to quantify at this stage. Potassium nitrate of rain origin has been found in the sheltered area, but no gypsum. Therefore, the biocolonization is a fast phenomenon on the stone and the physico-chemical processes derived from it, caused by climate and pollution, are slower. This is in agreement with the long-term observations made on old and unrestored graves of the cemetery described in the literature. [ABSTRACT FROM AUTHOR]

Zearalenone (ZEN) is a fungal toxin produced by Fusarium that widely occurs in various types of grains and feed. It has strong reproductive toxicity and a wide range of distribution, which will impact food and feed safety. In this study, Bacillus subtilis ZENL09, which is capable of transforming ZEN was investigated. By optimizing the fermentation conditions, the supernatant of Bacillus subtilis ZENL09 fermentation can achieve about 88% degradation rate of ZEN after reacting with ZEN for 12 h. The degradation product was collected by high-performance liquid chromatography, followed by LC-Q-TOF and MS/MS analysis to identify the changes in molecular mass and compound structure. The possible structure of the degradation product was also tentatively determined. Further evaluation of the degradation products' cytotoxicity was conducted using HepG2 cells, and the results indicated a significant reduction in toxicity compared to ZEN. Detoxification experiments on corn steep liquor showed that the fermentation supernatant of Bacillus subtilis degraded 87% of ZEN within 12 h, which further validates its potential application for detoxification in food and agricultural products. [ABSTRACT FROM AUTHOR]

The use of fossil fuels leads to environmental contamination during their extraction, processing and distribution. Microbial biodegradation provides a sustainable method for cleaning contaminated areas which follows the principles of sustainability. This paper presents the dynamics of biodegradation of hydrocarbon fractions of diesel oil, using Planomicrobium sp. and Rhodococcus sp. isolated from petroleum-contaminated sites. GC–MS analysis was employed to analyse abundances of the specific compounds such as n-alkanes, isoprenoids, sesquitepranes, hopanes, steranes and aromatic compounds (naphthalene and its methylated homologues, phenanthrene and anthracene and their methylated homologues, and dibenzothiophene and its methylated homologues). The obtained results showed that after 30 days of biodegradation of diesel, a significant degradation was achieved, with almost complete degradation of n-alkanes and a decrease in the amount of sesquiterapanes. Rhodococcus sp. had a higher efficiency in degradation of n-alkanes, while Planomicrobium sp. had a higher efficiency in the degradation of branched hydrocarbons. Both strains showed high activity in the biodegradation of sesquitepranes and demonstrate ability to degrade methylated phenanthrenes. Additionally, dimethyl-dibenzothiophenes were almost completely degraded and removed from the system. This study presents the first comprehensive report on the GC–MS analysis of the diesel biodegradation pattern of the Planomicrobium sp., compared with the well-established Rhodococcus sp. [ABSTRACT FROM AUTHOR]