Transformation of the recalcitrant pharmaceutical compound carbamazepine by Pleurotus ostreatus: role of cytochrome P450 monooxygenase and manganese peroxidase

Transformation and Degradation of PAH Mixture in Contaminated Sites: Clarifying Their Interactions with Native Soil Organisms

Soil contamination of polycyclic aromatic hydrocarbons (PAHs), especially caused by the mixture of two or more PAHs, raised great environmental concerns. However, research on the migration and transformation processes of PAHs in soils and their interactions with native communities is limited. In this work, soil samples from uncontaminated sites around the industrial parks in Handan, Hengshui, and Shanghai were artificially supplemented with three concentrations of anthracene (Ant), 9-chloroanthracene (9-ClAnt), benzopyrene (BaP), and chrysene (Chr). Ryegrass was planted to investigate the degradation of PAHs and its interaction with native soil organisms in the constructed ryegrass-microbe-soil microcosmic system. The bacterial and fungal communities in soil were affected by PAHs; their species diversity and relative abundance changed after exposure to different concentrations of PAHs, among which Lysobacter, Bacillus, Pseudomonas, and Massilia bacteria were correlated to the degradation of PAHs. On the 56th day, the contents of BaP, Chr, and Ant decreased with the degradation process, while the degradation of 9-ClAnt was limited. Nineteen intermediates, including hydroxylation and carboxylated compounds, were identified. The present research would help clarify the potential interactions between PAHs and native organisms in contaminated sites, providing fundamental information for evaluating the transformation risks of PAHs in the natural environment.

Low uptake of pharmaceuticals in edible mushrooms grown in polluted biogas digestate

The uptake dynamics of two sulfonamide antibiotics, two fluoroquinolone antibiotics, and the anticonvulsant carbamazepine during the cultivation of two species of edible mushrooms (Agaricus subrufescens and A. bisporus) was investigated. None of the antibiotics were accumulated by the mushrooms, while carbamazepine and its transformation product carbamazepine-10,11-epoxide were taken up by A. bisporus fruiting body but only in small amounts (up to 0.76 and 1.85 μg kg-1 dry weight, respectively). The sulfonamides were quickly removed from the mushroom growth substrate, while the recalcitrant fluoroquinolones and carbamazepine were only partially removed. Dissipation half-lives were generally lower for A. subrufescens than A. bisporus, but A. subrufescens was also grown at a slightly higher culture temperature. A. subrufescens also showed a lower uptake of contaminants. Comparison of maximum dietary intake with other common exposure sources showed that these mushrooms can safely be eaten although produced on a polluted substrate, with respect to the investigated compounds.

Mycofiltration of Aqueous Iron (III) and Imidacloprid Solutions, and the Effects of the Filtrates on Selected Biomarkers of the Freshwater Snail Helisoma duryi

To alleviate the burden of water contamination, a newly developed form of bioremediation known as mycofiltration can be employed. Mycofiltration is an environment-friendly technology involving the treatment of contaminated water by passing it through a network of saprophytic fungal mycelium. A mycofilter made of Pleurotus ostreatus was used for the removal of iron (III) and imidacloprid from aqueous solutions. Batch mycofiltration, at a dosage of 1 g of mycofilter per 50 mL, was performed on iron (III) solutions of different concentrations (0.99, 10.7, 22.9, and 27.72 mg/L) and pH (3.3, 7 and 11). For column mycofiltration, the mycofilter was packed into pyrex columns (3.3 × 15 cm) to desired bed heights. Iron (III) and imidacloprid solutions of 18.99 mg/L and 234.70 ng/L, respectively, were filtered at a constant flow rate. Thereafter, Helisoma duryi snails were exposed for 96 h to the respective filtrates, and their catalase and acetylcholinesterase activities were assessed. Batch mycofiltration showed iron (III) removal rates as high as 85%. Column mycofiltration showed removal rates of 94 and 31% for iron (III) and imidacloprid, respectively. Catalase activity was significantly reduced (p < 0.05) in the snails exposed to iron (III) or imidacloprid filtrates, compared to the snails exposed to the non-mycofiltered media. A significantly higher acetylcholinesterase activity was induced by iron (III) filtrates in comparison with the non-mycofiltered media (p < 0.05). There were no significant differences in acetylcholinesterase activity (p > 0.05) in the snails exposed to mycofiltered and non-mycofiltered imidacloprid media. Mycofilter characterisation using Fourier Transform Infrared Spectrophotometry revealed significant changes in transmittance intensity in the mycofilters used for the iron (III) vs the ones used for the imidacloprid solutions. Mycofiltration was found to improve water quality although iron (III) was removed more effectively than imidacloprid.

Pharmaceutical and personal care products (PPCPs) degradation and microbial characteristics of low-temperature operation combined with constructed wetlands

Emerging contaminants (ECs), which are present in water bodies, could cause global environmental and human health problems. These contaminants originate from various sources such as hospitals, clinics, households, and industries. Additionally, they can also indirectly enter the water supply through runoff from agriculture and leachate from landfills. ECs, specifically Pharmaceutical and personal care products (PPCPs), are causing widespread concern due to their contribution to persistent water pollution. Traditional approaches often involve expensive chemicals and energy or result in the creation of by-products. This study developed a practical and environmentally-friendly method for removing PPCPs, which involved combining and integrating various techniques. To implement this method, it was necessary to establish and used a field simulator based on the real-life scenario. Based on the data analysis, the average removal rates of COD, TP, TN, and NH4+-N were 57%, 59%, 63%, and 73%, respectively. the removal rate of PPCPs by CCWs was found to be 82.7% after comparing samples that were not treated by constructed wetlands and those that were treated. Combined constructed wetlands (CCWs) were found to effectively remove PPCPs from water. This is due to the combined action of plant absorption, absorption, and biodegradation by microorganisms living in the wetlands. Interestingly, the wetland plant reed had been shown to play an important role in removing these pollutants. Microbial degradation was the most important pathway for PPCPs removal in CCWs. Carbamazepine was selected as a typical PPCP for analysis. In addition, the microbial community structure of the composite filler was also investigated. High-throughput sequencing confirmed that the dominant bacteria had good adaptability to PPCPs. This technique not only reduced the potential environmental impact but also served as a foundation for further research on the use of constructed wetlands for the treatment of PPCPs contaminated water bodies and its large-scale implementation.

Various species of Basidiomycota fungi reveal different abilities to degrade pharmaceuticals and also different pathways of degradation

The presence of pharmaceuticals (PhACs) in the aquatic environment is an emerging problem worldwide. PhACs reach surface water via the effluents of wastewater treatment plants (WWTPs). WWTPs, although able to remove organic pollutants, do not always remove PhACs. Currently, in the treatment of sewage with the activated sludge method, numerous microorganisms are used, mostly bacteria. Nevertheless, these microorganisms are not resistant to many drug contaminants, and some may also pose a risk to human health. White-rot fungi (WRF), which degrade a wide spectrum of environmental pollutants, may be used as an alternative to microorganisms. However, little data exists comparing the removal of various PhACs by different WRF. In this study, we aimed to determine the ability of three WRF Basidiomycota species, Armillaria mellea, Phanerochaete chrysosporium, and Pleurotus ostreatus, to remove PhACs from various therapeutic groups over the course of 1 h-4 days. Additionally, we identified the fungal metabolites of PhACs, proposed the degradation pathways, and assessed the toxicity of the post-culture media. All selected WRF removed PhACs, but the degree of removal depended on WRF species and PhACs type. Antidepressants and immunosuppressants were removed most efficiently by P. ostreatus, cardiovascular drugs and sulfamethoxazole by A. mellea, and erythromycin by P. chrysosporium. The vast differences observed highlight the need for more intensive testing of different WRF species to select the best species for removing pharmaceuticals of interest. The structure of metabolites generated during degradation strongly depended on WRF species, but the most frequent xenobiotic transformations were oxidation and dealkylation. The obtained results gave insight into the substrate specificity of selected WRF while also providing a broad extension of the knowledge of pharmaceutical degradation by A. mellea.

The potential of fungi in the bioremediation of pharmaceutically active compounds: a comprehensive review

The ability of fungal species to produce a wide range of enzymes and metabolites, which act synergistically, makes them valuable tools in bioremediation, especially in the removal of pharmaceutically active compounds (PhACs) from contaminated environments. PhACs are compounds that have been specifically designed to treat or alter animal physiological conditions and they include antibiotics, analgesics, hormones, and steroids. Their detrimental effects on all life forms have become a source of public outcry due their persistent nature and their uncontrolled discharge into various wastewater effluents, hospital effluents, and surface waters. Studies have however shown that fungi have the necessary metabolic machinery to degrade PhACs in complex environments, such as soil and water, in addition they can be utilized in bioreactor systems to remove PhACs. In this regard, this review highlights fungal species with immense potential in the biodegradation of PhACs, their enzymatic arsenal as well as the probable mechanism of biodegradation. The challenges encumbering the real-time application of this promising bioremediative approach are also highlighted, as well as the areas of improvement and future perspective. In all, this paper points researchers to the fact that fungal bioremediation is a promising strategy for addressing the growing issue of pharmaceutical contamination in the environment and can help to mitigate the negative impacts on ecosystems and human health.

Continuous operation of fungal wheel reactor based on solid-state fermentation for the removal of pharmaceutical and personal care products

Wood-rotting fungi and their enzymatic systems represent promising biocatalysts for the removal of pharmaceuticals and personal care products (PPCPs) from wastewater. We designed a fungal wheel reactor (FWR) based on solid-state fermentation (SSF) of Trametes versicolor and a lignocellulosic substrate, which was used as an immobilization carrier for fungal biomass and the sole initial nutrient source for producing fungal oxidative enzymes. Three pharmaceutical and personal care products, acetaminophen, bisphenol A and carbamazepine, were spiked into the synthetic wastewater and the treatment was carried out under non-sterile conditions. Acetaminophen was completely removed from the FWR until laccase was observed. The acetaminophen removal efficiency was retrieved by replacing the fungal wheel with fresh SSF products. Bisphenol A and carbamazepine were removed via enzymatic activity and adsorption. When the fungal wheel was replaced, acetaminophen began to be completely removed, even after laccase depletion. The microbial community analysis indicated that the continuous removal of acetaminophen was mainly due to the high proportion of T. versicolor. The relative abundance of the co-occurring microbial community might be responsible for the divergence in acetaminophen removal between two of fungal wheel-replaced reactors. Overall, FWRs are promising tools for the removal of PPCPs by highly reactive enzymatic mechanisms as well as adsorption on the carrier surface. By replacing SSF and settled microbial communities, FWRs may continuously contribute to bioremediation over a long-term period.

Identification of a Phase I mechanism gene of rice (OsCYP1) in response to isoproturon

The long-term use of isoproturon may threaten food security and human health. Cytochrome P450 (CYP or P450) can catalyze the biosynthetic metabolism, and play a crucial role in the modification of plant secondary metabolites. Therefore, it is of great importance to explore the genetic resources for isoproturon degradation. This research focused on a phase I metabolism gene (OsCYP1) with significant differential expression in rice under isoproturon pressure. Specifically, the high-throughput sequencing results of rice seedling transcriptome in response to isoproturon stress were analyzed. The molecular information and tobacco subcellular localization of OsCYP1 were studied. The subcellular localization of OsCYP1 in tobacco was assessed, where it is located in the endoplasmic reticulum. To analyze the expression of OsCYP1 in rice, the wild-type rice was treated with 0-1 mg/L isoproturon for 2 and 6 days, and qRT-PCR assays were conducted to detect the transcription levels. Compared with the control group, the expression of OsCYP1 in shoots was progressively upregulated after exposure to isoproturon, with 6.2-12.7-fold and 2.8-7.9-fold increases in transcription levels, respectively. Moreover, treatment with isoproturon upregulated the expression of OsCYP1 in roots, but the upregulation of transcripts was not significant except for 0.5 and 1 mg/L isoproturon at day 2. To confirm the role of OsCYP1 in enhancing isoproturon degradation, the vectors overexpressing OsCYP1 were transformed into recombinant yeast cells. After exposure to isoproturon, the growth of OsCYP1-transformed cells was better than the control cells, especially at higher stress levels. Furthermore, the dissipation rates of isoproturon were increased by 2.1-, 2.1- and 1.9-fold at 24, 48 and 72 h, respectively. These results further verified that OsCYP1 could enhance the degradation and detoxification of isoproturon. Collectively, our findings imply that OsCYP1 plays vital role in isoproturon degradation. This study provides a fundamental basis for the detoxification and regulatory mechanisms of OsCYP1 in crops via enhancing the degradation and/or metabolism of herbicide residues.

Carbamazepine degradation and genome sequencing of a novel exoelectrogen isolated from microbial fuel cells

Extracellular electron transfer and pharmaceutical products degradation mechanisms of electrochemical active microbial are helpful in optimizing electricity generation and biotoxic contaminants removal for microbial fuel cells (MFCs). An exoelectrogenic bacterial strain (designated as LYK-6) capable of degrading carbamazepine was first isolated from MFCs operated with carbamazepine as unique fuel. The strain LYK-6 was identified as the member of Pseudomonas genus according to morphological characteristics and 16S rRNA gene sequence analysis. Carbamazepine degradation rate of the strain LYK-6 was determined as 56.28% in inorganic salt medium using carbamazepine as sole carbon source. There were two oxidation peaks located at -0.044 V and 0.288 V revealed with differential pulse voltammetry analysis of the strain LQK-6. The maximum voltage of MFCs inoculated the strain LYK-6 reached to 187 mV when the MFCs fed with carbamazepine. The complete genome of the strain LYK-6 was of 4,454,672 bp in length and encoding 4209 protein genes. Genome annotation and functional gene analysis showed that the strain LYK-6 had significant genes encoding proteins responsible for the degradation of carbamazepine. The results demonstrated that the strain LYK-6 was promising application for the treatment of carbamazepine contaminant water by MFCs. This finding increases the known diversity of exoelectrogens.

Bioremediation of organic pollutants by white rot fungal cytochrome P450: The role and mechanism of CYP450 in biodegradation

Cytochrome P450 (CYP450) is a well-known protein family that is widely distributed in many organisms. Members of this family have been implicated in a broad range of reactions involved in the metabolism of various organic compounds. Recently, an increasing number of studies have shown that the CYP450 enzyme also participates in the elimination and degradation of organic pollutants, by white rot fungi (WRF), a famous group of natural degraders. This paper reviews previous investigations of white rot fungal CYP450 involved in the biodegradation of organic pollutants, with a special focus on inhibitory experiments, and the direct and indirect evidence of the role of white rot fungal CYP450 in bioremediation. The catalytic mechanisms of white rot fungal CYP450, its application potential, and future prospect for its use in bioremediation are then discussed.

Nocardioides carbamazepini sp. nov., an ibuprofen degrader isolated from a biofilm bacterial community enriched on carbamazepine

From the metagenome of a carbamazepine amended selective enrichment culture the genome of a new to science bacterial species affiliating with the genus Nocardioides was reconstructed. From the same enrichment an aerobic actinobacterium, strain CBZ_1^T, sharing 99.4% whole-genome sequence similarity with the reconstructed Nocardioides sp. bin genome was isolated. On the basis of 16S rRNA gene sequence similarity the novel isolate affiliated to the genus Nocardioides, with the closest relatives Nocardioides kongjuensis DSM19082^T (98.4%), Nocardioides daeguensis JCM17460^T (98.4%) and Nocardioides nitrophenolicus DSM15529^T (98.2%). Using a polyphasic approach it was confirmed that the isolate CBZ_1^T represents a new phyletic lineage within the genus Nocardioides. According to metagenomic, metatranscriptomic studies and metabolic analyses strain CZB_1^T was abundant in both carbamazepine and ibuprofen enrichments, and harbors biodegradative genes involved in the biodegradation of pharmaceutical compounds. Biodegradation studies supported that the new species was capable of ibuprofen biodegradation. After 7 weeks of incubation, in mineral salts solution supplemented with glucose (3 g l^-1) as co-substrate, 70% of ibuprofen was eliminated by strain CBZ_1^T at an initial conc. of 1.5 mg l^-1. The phylogenetic, phenotypic and chemotaxonomic data supported the classification of strain CBZ_1^T to the genus Nocardioides, for which the name Nocardioides carbamazepini sp. nov. (CBZ_1^T = NCAIM B.0.2663 = LMG 32395) is proposed. To the best of our knowledge, this is the first study that reports simultaneous genome reconstruction of a new to science bacterial species using metagenome binning and at the same time the isolation of the same novel bacterial species.

Exploring an enhanced rhizospheric phenomenon for pluricontaminated soil remediation: Insights from tripartite metatranscriptome analyses

Phytoremediation involving the use of microorganisms with tolerant plant species represents a new frontier for on-site remediation of pluricontaminated soils. In this study, the effectiveness of a biotechnological strategy, involving the use of Festuca arundinacea and a pool of microorganisms, was assessed by a mesocosm experiment and an in-depth rhizospheric metatranscriptomic analysis. The chemical profile of mesocosm soil at the end of the experiment (240 days) showed that the decrease of trace elements such as Cd, Hg, Pb, Sn, Tl, V and Zn in the soil was enhanced by our biological combination. Additionally, also the organic pollutants (PAHs and PCBs) were strongly reduced up to 40.5%. About two million transcripts were identified and used for taxonomic and functional profiling. Transcripts read counts, tripartite among plant, bacteria and fungi were identified and quantified to provide an overview of the complex soil community composition. We observed that Actinobacteria and fungi abundance might be involved in remediation success. Functional analyses showed that Trehalose Biosynthesis and the antioxidant activity might have played a key-role in metaorganism effective interactions. The biotechnological approach remodeled the transcriptional profile toward organic pollutant degradation and heavy metal stress response.

Assessing a co-culture fungal granule ability to remove pharmaceuticals in a sequencing batch reactor

Biodegradation of carbamazepine (CBZ), diclofenac sodium (DCF) and ibuprofen (IBP) was evaluated through fungal granules development in a sequencing batch reactor (SBR). Fungal granules were developed in co-culture of T. polyzona, A. niger, T. longibrachiatum, M. circinelloides and R. microsporus at a retention time (RT) of 2 days and 1 day. Ligninolytic enzymes [laccase (Lac), lignin peroxidase (LiP) and manganese peroxidase (MnP)] were determined. Removal of pharmaceuticals was assessed and metabolites identified using the SPE-UPLC-QToF/MS methods. A pH range of 3-4.6 was found to improve the granulation development from day 6 and the production of ligninolytic enzymes [MnP (253.00 ± 14.19 U/L), Lac (111.58 ± 10.00 U/L) and LiP (95.25 ± 8.22 U/L)]. At steady-state, a removal of 97.41±0.25%, 99.83±0.14%, and 99.91±0.08 were achieved at an RT of 2 days for CBZ, DCF, and IBP, respectively, and of 91.94±0.05%, 99.31±0.12% and 97.72±0.23% at an RT of 1 days for the same PhCs. A variety of chemical reactions have been proposed for degradation pathways catalysed by enzyme-producing fungi, generating fragment ions of intermediate compounds. This study is highly relevant for cost-effective and environmentally friendly wastewater treatment processes in water scare countries.

Uptake of perfluoroalkyl substances, pharmaceuticals, and parabens by oyster mushrooms (Pleurotus ostreatus) and exposure risk in human consumption

Organic micropollutants (MPs) pose potential threats to environmental ecosystems and human health. This study investigated uptake of perfluoroalkyl substances (PFASs), pharmaceuticals, and paraben by edible oyster mushrooms (Pleurotus ostreatus), cultivated on spiked growth substrate. Concentrations of pharmaceuticals and paraben in substrate showed a decreasing trend over a 20-day harvesting period, whereas PFAS concentrations were variable over the harvesting period. However, only propylparaben, clarithromycin, and PFASs were detected in fruiting bodies of oyster mushroom. Uptake of PFASs by oyster mushroom fruit bodies was negatively correlated with perfluorocarbon chain length. An impact of MPs on fungal colonization was observed, with decreased respiration in treatments with the highest concentration of MPs, but production of fruiting bodies was not affected by exposure level. The potential human risk from ingestion of MPs was evaluated for oyster mushrooms exposed to the highest concentration of MPs in substrate, based on acceptable daily intake (ADI).

Fluoxetine Removal from Aqueous Solutions Using a Lignocellulosic Substrate Colonized by the White-Rot Fungus Pleurotus ostreatus

One of the main challenges in both the design of new wastewater treatment plants and the expansion and improvement of existing ones is the removal of emerging pollutants. Therefore, the search for economic and sustainable treatments is needed to enhance the removal of pharmaceuticals. The potential of a lignocellulosic substrate colonized by Pleurotus ostreatus, a waste from mushroom production, to remove fluoxetine from aqueous solutions was studied. Batch assays were performed to remove 600 µg∙L⁻¹ fluoxetine from aqueous solutions using the colonized mushroom substrate (CMS) and crude enzyme extracts. The removal efficiencies achieved were, respectively, ≥83.1% and 19.6% in 10 min. Batch assays with sterilized CMS and 1-aminobenzotriazole (to inhibit cytochrome P450 enzymes) showed that the higher removal efficiencies achieved in the CMS assays may be attributed to the synergistic contribution of biosorption onto the CMS and lignin modifying enzymes activity, namely laccase activity. A column assay was performed with the CMS, fed with 750 µg∙L⁻¹ fluoxetine aqueous solution. The removal efficiency was 100% during 30 min, decreasing to a final value of 70% after 8 h of operation. The results suggested that CMS can be a promising eco-friendly alternative to remove fluoxetine from aqueous solutions.

Investigation of promoter regions, motifs, and CpG islands in the regulation of gene expression in Trametes hirsuta strain 072

Background

In silico analysis of transcription start sites, promoter regions, transcription factors and their binding sites, and CpG islands for the Trametes hirsuta strain 072 genome were performed to understand the regulation mechanisms of gene expression and its genetic variations in the genomes. Therefore, a computational survey was carried out for the Trametes hirsuta strain 072 genome with the open reading frames from the National Center for Biotechnology Information database. Seventeen functional sequences were used to analyze promoter regions and their regulatory elements.

Result

The present study revealed that 94% of Trametes hirsuta strain 072 genes contained more than two TSSs. Among these identified TSSs, a TSS with the highest predictive score was considered to determine a promoter region of the genes. Moreover, a total of five common candidate motifs such as MotI, MotII, MotIII, MotIV, and MotV were identified. Among these motifs, motif IV was investigated as the common promoter motif for 41.17% of genes that serve as binding sites for transcription factors (TFs) involved in the expression regulation of Trametes hirsuta strain 072 genes. Motif IV was also compared to registered motifs in publically available databases to see if they are similar to known regulatory motifs for TF using TOMTOM web server. Hence, it was revealed that MotIV might serve as the binding site mainly for the leucine zipper TF gene family to regulate a gene expression of Trametes hirsuta strain 072. Regarding CpG island determination, it was concluded that there is no CpG island in both promoter and gene body regions of the Trametes hirsuta strain 072 genome.

Conclusions

This study provides a better insight into further molecular characterization which aimed to efficiently exploit a white rot fungus, Trametes hirsuta strain 072, for several biotechnological applications aimed to revitalize a severely contaminated environment.

Bioremediation of triphenyl phosphate by Pycnoporus sanguineus: Metabolic pathway, proteomic mechanism and biotoxicity assessment

So far, no information about the biodegradability of TPhP by white rot fungi has previously been made available, herein, Pycnoporus sanguineus was used as the representative to investigate the potential of white rot fungi in TPhP bioremediation. The results suggested that the biodegradation efficiency of 5 mg/L TPhP by P. sanguineus was 62.84% when pH was adjusted to 6 and initial glucose concentration was 5 g/L. Seven biodegradation products were identified, indicating that TPhP was biotransformed through oxidative cleavage, hydroxylation and methylation. The proteomic analysis revealed that cytochrome P450s, aromatic compound dioxygenase, oxidizing species-generating enzymes, methyltransferases and MFS general substrate transporters might occupy important roles in TPhP biotransformation. Carboxylesterase and glutathione S-transferase were induced to resist TPhP stress. The biotreatment by P. sanguineus contributed to a remarkable decrease of TPhP biotoxicity. Bioaugmentation with P. sanguineus could efficiently promote TPhP biodegradation in the water-sediment system due to the cooperation between P. sanguineus and some putative indigenous degraders, including Sphingobium, Burkholderia, Mycobacterium and Methylobacterium. Overall, this study provided the first insights into the degradation pathway, mechanism and security risk assessment of TPhP biodegradation by P. sanguineus and verified the feasibility of utilizing this fungus for TPhP bioremediation applications.

An assessment of Pleurotus ostreatus to remove sulfonamides, and its role as a biofilter based on its own spent mushroom substrate

A double strategy based on the removal of sulfonamide antibiotics by Pleurotus ostreatus and adsorption on spent mushroom substrate was assessed to reclaim contaminated wastewater. P. ostreatus was firstly tested in a liquid medium fortified with five sulfonamides: sulfamethoxazole, sulfadiazine, sulfathiazole, sulfapyridine and sulfamethazine, to evaluate its capacity to remove them and to test for any adverse effects on fungal growth and for any reduction in residual antibiotic activity. P. ostreatus was effective in removing sulfonamides up to 83 to 91% of the applied doses over 14 days. The antibiotic activity of the sulfonamide residues was reduced by 50%. Sulfamethoxazole transformation products by laccase were identified, and the degradation pathway was proposed. In addition, P. ostreatus growth on a semi-solid medium of spent mushroom substrate and malt extract agar was used to develop a biofilter for the removal of sulfonamides from real wastewater. The biofilter was able to remove more than 90% of the sulfonamide concentrations over 24 h by combining adsorption and biodegradation mechanisms.

Antimicrobial chloro-hydroxylactones derived from the biotransformation of bicyclic halolactones by cultures of Pleurotus ostreatus

The aim of this research was to test the ability of cultures of edible fungi to biotransform three bicyclic halolactones. The substrates (2-chloro-, 2-bromo- and 2-iodo-4,4,6,7-tetramethyl-9-oxabicyclo[4.3.0]nonan-8-one) received by means of synthesis were transformed by oyster mushroom Pleurotus ostreatus and edible mushrooms of the genus Armillaria mellea, Marasmius scorodonius and Laetiporus sulfureus. The substrates were converted to hydroxyl derivatives only by the cultures of oyster mushroom. Out of seven strains of Pleurotus ostreatus - three were capable of hydroxylation of all substrates with the most effective conversion of chlorolactone. Bromo- and iodolactone were transformed to a small extent. Four new chloro-hydroxylactones were obtained as biotransformation products. The structures of substrates and products were established on the basis of spectroscopic data. Studies of antimicrobial activity performed on reference strains of pathogenic microorganisms showed that halolactones caused complete inhibition of growth of A. alternata and F. linii strains. On the other hand, chloro-hydroxylactones were able to completely inhibit the growth of A. alternata and F. linii strains and also C. albicans strain.

Fate and impact of pharmaceuticals and personal care products during septage co-composting using an in-vessel composter

The present study aimed at understanding the impact of pharmaceutical and personal care product (PPCP) load on compost dynamics and fate of PPCPs during the composting. In addition, the compost dynamics during single PPCP degradation and multiple PPCPs degradation were investigated. Results revealed that co-composting could degrade the pharmaceutical, carbamazepine (CBZ) up to 83% during single pollutant degradation while it was 66% during multiple pollutant system, at an initial concentration (IC) of 5 mg/kg dw. In case of personal care product, namely triclosan (TCS), single pollutant degradation resulted in 86% removal whereas the removal efficiency was 83% in multiple pollutant system. Relatively high concentration of CBZ showed a negative impact on compost dynamics compared to that of TCS. Higher IC resulted in lower temperature development and relatively lower pollutant removal. The study on pollutant transfer in compost solid surface and in leachate revealed that TCS was not leached out while the leaching of CBZ was significant during composting process. The various transformation products formed during composting were identified and tentative pathways for CBZ and TCS degradation were proposed.

Biotransformation of ibuprofen in biological sludge systems: Investigation of performance and mechanisms

Ibuprofen (IBU), a common non-steroidal anti-inflammatory drug (NSAID), is widely used by humans for controlling fever and pain, and is frequently detected in the influent of wastewater treatment plants and different aquatic environments. In this study, the biotransformation of IBU in activated sludge (AS), anaerobic methanogenic sludge (AnMS) and sulfate-reducing bacteria (SRB)-enriched sludge systems was investigated at three different concentrations of 100, 500 and 1000 μg/L via a series of batch and continuous studies. IBU at concentration of 100 μg/L was effectively biodegraded by AS whereas AnMS and SRB-enriched sludge were less effective in IBU biodegradation at all concentrations tested. However, at higher IBU concentrations of 500 and 1000 μg/L, AS showed poor IBU biodegradation and chemical oxygen demand (COD) removal due to inhibition of aerobic heterotrophic bacteria (i.e., Candidatus Competibacter) by IBU and/or IBU biotransformation products. The microbial analyses showed that IBU addition shifted the microbial community structure in AS, AnMS and SRB-enriched sludge systems, however, the removals of COD, nitrogen and sulfur in both anaerobic sludge systems were not affected significantly (p > 0.05). The findings of this study provided a new insight into biotransformation of IBU in three important biological sludge systems.

Effect of hexavalent chromium on the biodegradation of tetrabromobisphenol A (TBBPA) by Pycnoporus sanguineus

The influence of Cr(VI) on the degradation of tetrabromobisphenol A (TBBPA) by a typical species of white rot fungi, Pycnoporus sanguineus, was investigated in this study. The results showed that P. sanguineus together with its intracellular and extracellular enzyme could effectively degrade TBBPA. The degradation efficiency of TBBPA by both P. sanguineus and its enzymes decreased significantly when Cr(VI) concentration increased from 0 to 40 mg/L. The subsequent analysis about cellular distribution of TBBPA showed that the extracellular amount of TBBPA increased with the increment of Cr(VI) concentration, but the content of TBBPA inside fungal cells exhibited an opposite variation tendency. The inhibition of TBBPA degradation by P. sanguineus was partly attributed to the increase of cell membrane permeability and the decrease of cell membrane fluidity caused by Cr(VI). In addition, the decline of H⁺-ATPase and Mg²⁺-ATPase activities was also an important factor contributing to the suppression of TBBPA degradation in the system containing concomitant Cr(VI). Moreover, the activities of two typical extracellular lignin-degrading enzymes of P. sanguineus, MnP and Lac, were found to descend with ascended Cr(VI) level. Cr(VI) could also obviously suppress the gene expression of four intracellular enzymes implicated in TBBPA degradation, including two cytochrome P450s, glutathione S-transferases and pentachlorophenol 4-monooxygenase, which resulted in a decline of TBBPA degradation efficiency by fungal cells and intracellular enzyme in the presence of Cr(VI). Overall, this study provides new insights into the characteristics and mechanisms involved in TBBPA biodegradation by white rot fungi in an environment where heavy metals co-exist.

Biotransformation and detoxification of the neonicotinoid insecticides nitenpyram and dinotefuran by Phanerochaete sordida YK-624

Neonicotinoid insecticides have been widely used throughout the world over the last two decades. In the present study, we investigated the degradation of neonicotinoid insecticides nitenpyram (NIT) and dinotefuran (DIN) by the white-rot fungus Phanerochaete sordida YK-624. While NIT was completely degraded by P. sordida YK-624 under ligninolytic conditions, only a 20% decrease was observed under nonligninolytic conditions. On the other hand, P. sordida YK-624 degraded 31% of DIN under ligninolytic conditions after a 20-day incubation, while it did not degrade DIN under nonligninolytic conditions. We found that cytochromes P450 played a key role in the biotransformation of NIT and DIN by P. sordida YK-624. A novel NIT metabolite (E)-N-((6-chloropyridin-3-yl)methyl)-N-ethyl-N'-hydroxy acetimidamide (CPMHA) and a novel DIN metabolite N-((4aS,7aS,E)-1-methylhexahydrofuro[2,3-d]pyrimidin-2(1H)-ylidene)nitramide (PHPF) were identified in this study. In addition, to evaluate neurotoxicity, the effects of NIT, DIN and their metabolites on the viability of human neuroblastoma cells SH-SY5Y were determined. PHPF showed higher neurological toxicity than DIN, whereas the metabolite of NIT, CPMHA, showed no toxic effect. Our results indicated that the neurological toxicity of NIT could be effectively removed by P. sordida YK-624.

Biodegradation of hydrolyzed polyacrylamide by a Bacillus megaterium strain SZK-5: Functional enzymes and antioxidant defense mechanism

Hydrolyzed polyacrylamide (HPAM) is the most widely used water-soluble linear polymer with high molecular weight in polymer flooding. Microbiological degradation is an environment-friendly and effective method of treating HPAM-containing oilfield produced water. In this study, a strain SZK-5 that could degrade HPAM was isolated from soil contaminated by oilfield produced water. Based on morphological, biochemical characteristics and 16S rDNA sequence homology analysis, the strain was identified as Bacillus megaterium. The biodegradation capability of strain SZK-5 was determined by incubation in a mineral salt medium (MSM) containing HPAM under different environmental conditions, showing 55.93% of the HPAM removed after 7 d of incubation under the optimum conditions ((NH₄)₂SO₄ = 1667.9 mg L^-1, temperature = 24.05 °C and pH = 8.19). Cytochrome P450 (CYP) and urease (URE) played significant roles in biological carbon and nitrogen removal, respectively. The strain SZK-5 could resist the damages caused by oxidative stress given by crude oil and HPAM. To our knowledge, this is the first report about the biodegradation of HPAM by B. megaterium. These results suggest that strain SZK-5 might be a new auxiliary microbiological resource for the biodegradation of HPAM residue in wastewater and soil.

The Use of Algae and Fungi for Removal of Pharmaceuticals by Bioremediation and Biosorption Processes: A Review

The occurrence and fate of pharmaceuticals in the aquatic environment is recognized as one of the emerging issues in environmental chemistry. Conventional wastewater treatment plants (WWTPs) are not designed to remove pharmaceuticals (and their metabolites) from domestic wastewaters. The treatability of pharmaceutical compounds in WWTPs varies considerably depending on the type of compound since their biodegradability can differ significantly. As a consequence, they may reach the aquatic environment, directly or by leaching of the sludge produced by these facilities. Currently, the technologies under research for the removal of pharmaceuticals, namely membrane technologies and advanced oxidation processes, have high operation costs related to energy and chemical consumption. When chemical reactions are involved, other aspects to consider include the formation of harmful reaction by-products and the management of the toxic sludge produced. Research is needed in order to develop economic and sustainable treatment processes, such as bioremediation and biosorption. The use of low-cost materials, such as biological matrices (e.g., algae and fungi), has advantages such as low capital investment, easy operation, low operation costs, and the non-formation of degradation by-products. An extensive review of existing research on this subject is presented.

Transformation of lamotrigine by white-rot fungus Pleurotus ostreatus

One of the most persistent pharmaceutical compounds commonly found in treated wastewater is lamotrigine (LTG). It has also been detected in soils and crops irrigated with treated wastewater. Here we focused on the ability of the white-rot edible mushroom Pleurotus ostreatus to remove and transform LTG in liquid cultures. At concentrations of environmental relevance (1 and 10 μg L^-1) LTG was almost completely removed from the culture medium within 20 days. To elucidate the mechanism of LTG removal and transformation, we applied a physiological-based approach using inhibitors and a competing agent. These experiments were conducted at a higher concentration for metabolites detection. Based on identification of sulfur-containing metabolites and LTG N2-oxide and the effect of specific inhibitors, cytochrome P450 oxidation is suggested as one of the reaction mechanisms leading to LTG transformation. The variety and number of transformation products (i.e., conjugates) found in the current study were larger than reported in mammals. Moreover, known conjugates with glucuronide, glutathione, or cysteine/glycine, were not found in our system. Since the majority of the identified transformation products were conjugates of LTG, this study highlights the persistence of LTG as an organic pollutant in ecosystems exposed to wastewater.

Long-term continuous treatment of non-sterile real hospital wastewater by Trametes versicolor

BACKGROUND

Hospital wastewater is commonly polluted with high loads of pharmaceutically active compounds, which pass through wastewater treatment plants (WWTPs) and end up in water bodies, posing ecological and health risks. White-rot fungal treatments can cope with the elimination of a wide variety of micropollutants while remaining ecologically and economically attractive. Unfortunately, bacterial contamination has impeded so far a successful implementation of fungal treatment for real applications.

RESULTS

This work embodied a 91-day long-term robust continuous fungal operation treating real non-sterile hospital wastewater in an air pulsed fluidized bed bioreactor retaining the biomass. The hydraulic retention time was 3 days and the ageing of the biomass was avoided through partial periodic biomass renovation resulting in a cellular retention time of 21 days. Evolution of microbial community and Trametes abundance were evaluated.

CONCLUSIONS

The operation was able to maintain an average pharmaceutical load removal of over 70% while keeping the white-rot fungus active and predominant through the operation.

Evaluation of diclofenac biodegradation by the ascomycete fungus Penicillium oxalicum at flask and bench bioreactor scales

Diclofenac (DFC) is a common anti-inflammatory drug, and has attracted the significant attention due to its massive use around the world and its environmental impact. In this work, we describe for the first time the use of Penicillium oxalicum, an ascomycetes fungus, for the biotransformation of DFC at flask and bench bioreactor scales. We present a complete study of the role of enzymes, metabolic pathway, acute toxicity assays and comparison between free and immobilised biomass. Pellets of P. oxalicum degraded 100 μM of DFC within 24 h, and the activity of CYP450 enzymes was key for the elimination of the drug. The scaling-up to bench bioreactor was optimised by the reduction of nutrients, and characterising the actions of free pellets, polyurethane foam- and plastic K1-immobilised biomass revealed free pellets to be the most efficient DFC removal system (total elimination occurred in 36 h). Hydroxylated metabolites were detected during the process, suggesting that a mixture of biological and physical processes were involved in the elimination of DFC. The use of P. oxalicum reduced the acute toxicity of the medium supplemented with diclofenac and represents a novel and attractive alternative for the elimination of pharmaceutical compounds.

Carbaryl biodegradation by Xylaria sp. BNL1 and its metabolic pathway

Although ascomycetes occupy a vaster niche in soil than the well-studied basidiomycetes, they have received limited attention in studies related to bioremediation. In this study, the degradation of carbaryl by Xylaria sp. was studied in different culture conditions and its possible metabolic pathway was elucidated. In liquid culture, 99% of the added carbaryl was eliminated when cytochrome P450 (CYP450) was active, which was similar to the degradation rate of Pleurotus ostreatus, a fungus with strong bioremediation ability. Mn²⁺ is beneficial to the degradation of carbaryl. Compared to the 72.17% degradation rate in sterile soil, 59.0% carbaryl was eliminated in non-sterile soil, which suggested that Xylaria sp. BNL1 can resist microorganismal infection. Furthermore, the intracellular fractions containing laccase, CYP450, and carbaryl esterase efficiently degraded carbaryl. The presence of carbaryl metabolites suggested that Xylaria sp. BNL1 initiated its attack on carbaryl via carbaryl esterase to release α-naphthol, which was further degraded to 1,4-naphthoquinone and benzoic acid by CYP450 and laccase. Thus, our study highlights the potential of using Xylaria sp. for bioremediation.

Physical and enzymatic properties of a new manganese peroxidase from the white-rot fungus Trametes pubescens strain i8 for lignin biodegradation and textile-dyes biodecolorization

A new manganese peroxidase-producing white-rot basidiomycete fungus was isolated from symptomatic wood of the camphor trees Cinnamomum camphora (L.) at the Hamma Botanical Garden (Algeria) and identified as Trametes pubescens strain i8. The enzyme was purified (MnP TP55) to apparent electrophoretic homogeneity and biochemically characterized. The specific activity and Reinheitzahl value of the purified enzyme were 221 U/mg and 2.25, respectively. MALDI-TOF/MS analysis revealed that the purified enzyme was a monomer with a molecular mass of 55.2 kDa. The NH₂-terminal sequence of the first 26 amino acid residues of MnP TP55 showed high similarity with those of white-rot fungal peroxidases. It revealed optimal activity at pH 5 and 40 °C. This peroxidase was completely inhibited by sodium azide and potassium cyanide, suggesting the presence of heme-components in its tertiary structure. Interestingly, MnP TP55 showed higher catalytic efficiency, organic solvent-tolerance, dye-decolorization ability, and detergent-compatibility than that of horseradish peroxidase (HRP) from roots of Armoracia rustanica, manganese peroxidase from Bjerkandera adusta strain CX-9 (MnP BA30), and manganese peroxidase from Phanerochaete chrysosporium (MnP PC). Overall, the findings provide strong support for the potential candidacy of MnP TP55 for environmental applications, mainly the development of enzyme-based technologies for lignin biodegradation, textile-dyes biodecolorization, and detergent formulations.

The effects of emerging environmental contaminants on Stenotrophomonas maltophilia isolated from drinking water in planktonic and sessile states

Concerns on the presence of emerging contaminants (ECs) in water sources have increased in recent years. The lack of efficient technologies to remove ECs from residual waters contributes for their appearance in drinking water distribution systems (DWDS). Therefore, sessile microorganisms on DWDS pipes are continuously exposed to trace concentrations of ECs. However, no data exists on the role of ECs on the resident microbiota. The present work aims to understand the effects of prolonged exposure of a bacterial strain of Stenotrophomonas maltophilia, isolated from a DWDS, in both planktonic and biofilm states, to trace concentrations of selected ECs (antipyrine-ANTP; diclofenac sodium salt-DCF; ibuprofen-IBP; galaxolide-GAL; tonalide-TON; carbamazepine-CBZ; clofibric acid-CA; tylosin-TY) on its tolerance to sodium hypochlorite (NaOCl) and resistance to antibiotics. Pre-established S. maltophilia biofilms were exposed to ECs for 26 d. Subsequently, the planktonic behaviour of the biofilm cells grown in the presence of ECS was characterized in terms of susceptibility to NaOCl and to selected antibiotics (levofloxacin and trimethoprim-sulfamethoxazole). Moreover, S.maltophilia was tested on its biofilm productivity in the presence of ECs (alone and mixed). These biofilms were challenged by NaOCl in order to assess the role of ECs on biofilm susceptibility. The results did not evidence remarkable effects of ECs on planktonic S. maltophilia susceptibility to NaOCl and antibiotics. However, S. maltophilia biofilm production and susceptibility to NaOCl was affected from ECs pre-exposure, particularly by the combination of different ECs (CA + CBZ, CA + IBP, CA + CBZ + IBP). S. maltophilia biofilms became more resistant to removal by NaOCl when developed in the presence of mixtures of CA + CBZ and CA + CBZ + IBP. Also, biofilm production was significantly affected. CA was present in all the combinations that altered biofilm behaviour. The overall results propose that exposure to ECs for 26 days had not a huge impact on S. maltophilia planktonic antimicrobial susceptibility. Nevertheless, the prolonged exposure to some ECs altered biofilm production and tolerance to NaOCl, with a potential practical outcome of hindering DWDS disinfection. The simultaneous presence of different ECs in the environment may amplify biofilm resilience.

Enzymes in removal of pharmaceuticals from wastewater: A critical review of challenges, applications and screening methods for their selection

At present, the removal of trace organic chemicals such as pharmaceuticals in wastewater treatment plants is often incomplete resulting in a continuous discharge into the aqueous environment. To overcome this issue, bioremediation approaches gained significant importance in recent times, since they might have a lower carbon footprint than chemical or physical treatment methods. In this context, enzyme-based technologies represent a promising alternative since they are able to specifically target certain chemicals. For this purpose, versatile monitoring of enzymatic reactions is of great importance in order to understand underlying transformation mechanisms and estimate the suitability of various enzymes exhibiting different specificities for bioremediation purposes. This study provides a comprehensive review, summarizing research on enzymatic transformation of pharmaceuticals in water treatment applications using traditional and state-of-the-art enzyme screening approaches with a special focus on mass spectrometry (MS)-based and high-throughput tools. MS-based enzyme screening represents an approach that allows a comprehensive mechanistic understanding of enzymatic reactions and, in particular, the identification of transformation products. A critical discussion of these approaches for implementation in wastewater treatment processes is also presented. So far, there are still major gaps between laboratory- and field-scale research that need to be overcome in order to assess the viability for real applications.

Removal of pharmaceutical compounds in water and wastewater using fungal oxidoreductase enzymes

Due to recalcitrance of some pharmaceutically active compounds (PhACs), conventional wastewater treatment is not able to remove them effectively. Therefore, their occurrence in surface water and potential environmental impact has raised serious global concern. Biological transformation of these contaminants using white-rot fungi (WRF) and their oxidoreductase enzymes has been proposed as a low cost and environmentally friendly solution for water treatment. The removal performance of PhACs by a fungal culture is dependent on several factors, such as fungal species, the secreted enzymes, molecular structure of target compounds, culture medium composition, etc. In recent 20 years, numerous researchers tried to elucidate the removal mechanisms and the effects of important operational parameters such as temperature and pH on the enzymatic treatment of PhACs. This review summarizes and analyzes the studies performed on PhACs removal from spiked pure water and real wastewaters using oxidoreductase enzymes and the data related to degradation efficiencies of the most studied compounds. The review also offers an insight into enzymes immobilization, fungal reactors, mediators, degradation mechanisms and transformation products (TPs) of PhACs. In brief, higher hydrophobicity and having electron-donating groups, such as amine and hydroxyl in molecular structure leads to more effective degradation of PhACs by fungal cultures. For recalcitrant compounds, using redox mediators, such as syringaldehyde increases the degradation efficiency, however they may cause toxicity in the effluent and deactivate the enzyme. Immobilization of enzymes on supports can enhance the performance of enzyme in terms of reusability and stability. However, the immobilization strategy should be carefully selected to reduce the cost and enable regeneration. Still, further studies are needed to elucidate the mechanisms involved in enzymatic degradation and the toxicity levels of TPs and also to optimize the whole treatment strategy to have economical and technical competitiveness.

Stropharia rugosoannulata and Gymnopilus luteofolius: Promising fungal species for pharmaceutical biodegradation in contaminated water

Pharmaceuticals are environmental micropollutants that pose an emerging challenge because they are poorly eliminated in conventional wastewater treatment plants. Over the last decade, many attempts have been made to solve this problem, and wastewater fungal treatment is a promising alternative. In this study, six different ligninolytic fungi (Trametes versicolor, Ganoderma lucidum, Irpex lacteus, Stropharia rugosoannulata, Gymnopilus luteofolius and Agrocybe erebia) were studied as bioremediation candidates for the removal and degradation of six recalcitrant pharmaceutical micropollutants: Carbamazepine (CBZ), Venlafaxine (VFX), Iopromide (IPD), Diclofenac (DCF), Cyclophosphamide (CFD) and Ifosfamide (IFD). Self-immobilization in a pellet shape was achieved for all fungal mycelia (which was the first time that this was reported for S. rugosoannulata, G. luteofolius, and A. erebia). Biodegradation achievement was greater than 90% for IPD with G. luteofolius and greater than 70% for CBZ with S. rugosoannulata, which suggests a great potential for this alternative biological treatment. Besides, this was the first report where fungal treatment achieved CFD and IFD removals greater than 20% for the treatment with T. versicolor, G. lucidum and S. rugosoannulata.

Metabolism of carbamazepine in plant roots and endophytic rhizobacteria isolated from Phragmites australis

Carbamazepine (CBZ) is a pharmaceutical frequently categorized as a recalcitrant pollutant in the aquatic environment. Endophytic bacteria previously isolated from reed plants have shown the ability to promote growth of their host and to contribute to CBZ metabolism. In this work, a horseradish (Armoracia rusticana) hairy root (HR) culture has been used as a plant model to study the interactions between roots and endophytic bacteria in response to CBZ exposure. HRs could remove up to 5% of the initial CBZ concentration when they were grown in spiked Murashige and Skoog (MS) medium. Higher removal rates were observed when HRs were inoculated with the endophytic bacteria Rhizobium radiobacter (21%) and Diaphorobacter nitroreducens (10%). Transformation products resulting from CBZ degradation were identified using liquid chromatography-ultra high-resolution quadrupole time of flight mass spectrometry (LC-UHR-QTOF-MS). CBZ metabolism could be divided in four pathways. Metabolites involving GSH conjugation and 2,3-dihydroxylation, as well as acridine related compounds are described in plants for the first time. This study presents strong evidence that xenobiotic metabolism and degradation pathways in plants can be modulated by the interaction with their endophytic community. Hence it points to plausible applications for the elimination of recalcitrant compounds such as CBZ from wastewater in CWs.

Laccase-Mediated Treatment of Pharmaceutical Wastes

Laccases are versatile multi-copper enzymes belonging to the superfamily of oxidase enzymes, which have been known since the nineteenth century. Recent discoveries have refined investigators' views of the potential of laccase as a magic tool for remarkable biotechnological purposes. A literature review of the capabilities of laccases, their assorted substrates, and their molecular mechanism of action now indicates the emergence of a new direction for laccase application as part of an arsenal in the fight against the contamination of water supplies by a number of frequently prescribed medications. This chapter provides a critical review of the literature and reveals the pivotal role of laccases in the elimination and detoxification of pharmaceutical contaminants in aquatic environments and wastewaters.

Exploitation of Trametes versicolor for bioremediation of endocrine disrupting chemicals in bioreactors

Endocrine disrupting chemicals (EDCs) are environmental contaminants causing increasing concerns due to their toxicity, persistence and ubiquity. In the present study, degradative capabilities of Trametes versicolor, Pleurotus ostreatus and Phanerochaete chrysosporium to act on five EDCs, which represent different classes of chemicals (phenols, parabens and phthalate) and were first applied as single compounds, were assessed. T. versicolor was selected due to its efficiency against target EDCs and its potentialities were exploited against a mixture of EDCs in a cost-effective bioremediation process. A fed-batch approach as well as a starvation strategy were applied in order to reduce the need for input of ‘fresh’ biomass, and avoid the requirement for external nutrients. The fungus was successfully operated in two different bioreactors over one week. Semi-batch cultures were carried out by daily adding a mixture of EDCs to the bioreactors in a total of five consecutive degradation cycles. T. versicolor was able to efficiently remove all compounds during each cycle converting up to 21 mg L^-1 day^-1 of the tested EDCs. The maintained ability of T. versicolor to remove EDCs without any additional nutrients represents the main outcome of this study, which enables to forecast its application in a water treatment process.

Mass spectrometry based in vitro assay investigations on the transformation of pharmaceutical compounds by oxidative enzymes

The ubiquitous presence of trace organic chemicals in wastewater and surface water leads to a growing demand for novel removal technologies. The use of isolated enzymes has been shown to possess the capability for a targeted application but requires a clearer mechanistic understanding. In this study, the potential of peroxidase from horseradish (HRP) and laccase from Pleurotus ostreatus (LccPO) to transform selected trace organic chemicals was studied using mass spectrometry (MS)-based in vitro enzyme assays. Conversion by HRP appeared to be more efficient compared to LccPO. Diclofenac (DCF) and sotalol (STL) were completely transformed by HRP after 4 h and immediate conversion was observed for acetaminophen (APAP). During treatment with LccPO, 60% of DCF was still detectable after 24 h and no conversion was found for STL. APAP was completely transformed after 20 min. Sulfamethoxazole (SMX), carbamazepine (CBZ), ibuprofen (IBP) and naproxen (NAP) were insusceptible to enzymatic conversion. In pharmaceutical mixtures, HRP exhibited a preference for DCF and APAP and the generally less efficient conversion of STL was enhanced in presence of APAP. Transformation product pattern after treatment with HRP revealed polymerization products for DCF while STL showed cleavage reactions. DCF product formation shifted towards a proposed dimeric iminoquinone product in presence of APAP whereas a generally less pronounced product formation in mixtures was observed for STL. In conclusion, the enzymatic treatment approach worked selectively and efficiently for a few pharmaceuticals. However, for application the investigation and possibly immobilization of multiplex enzymes being able to transform diverse chemical structures is recommended.

From the conventional biological wastewater treatment to hybrid processes, the evaluation of organic micropollutant removal: A review

Because of the recalcitrance of some micropollutants to conventional wastewater treatment systems, the occurrence of organic micropollutants in water has become a worldwide issue, and an increasing environmental concern. Their biodegradation during wastewater treatments could be an interesting and low cost alternative to conventional physical and chemical processes. This paper provides a review of the organic micropollutants removal efficiency from wastewaters. It analyses different biological processes, from conventional ones, to new hybrid ones. Micropollutant removals appear to be compound- and process- dependent, for all investigated processes. The influence of the main physico-chemical parameters is discussed, as well as the removal efficiency of different microorganisms such as bacteria or white rot fungi, and the role of their specific enzymes. Even though some hybrid processes show promising micropollutant removals, further studies are needed to optimize these water treatment processes, in particular in terms of technical and economical competitiveness.