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•Toxicity of benzophenone-3 was evaluated using microalgal growth inhibition test.•Benzophenone-3 led to significant changes in metabolism genes of Scenedesmus ...obliquus.•Benzophenone-3 was biodegraded through ring cleavage, hydroxylation, and methylation.•Benzophenone-3 was biotransformed into less toxic intermediates by microalgae.
Environmental contamination by benzophenone-3 has gained attention because of its frequent occurrence and adverse environmental impact. Studies investigating the toxicity and removal mechanisms, along with its degradation pathway in microalgae are still rare. In this study, the ecotoxicity of benzophenone-3 on Scenedesmus obliquus was assessed through dose-response test, risk quotient evaluation, and changes of microalgal biochemical characteristics and gene expression. The calculated risk quotients of benzophenone-3 were >1, implying its high environmental risk. Expression of the ATPF0C and Tas genes encoding ATP-synthase and oxidoreductase was significantly increased in S. obliquus after exposure to benzophenone-3, while that of Lhcb1 and HydA genes was reduced. When exposed to 0.1−3 mg L−1 benzophenone-3, 23–29 % removal was achieved by S. obliquus, which was induced by abiotic removal, bioadsorption, bioaccumulation and biodegradation. Metabolic fate analyses showed that biodegradation of benzophenone-3 was induced by hydroxylation, and methylation, forming less toxic intermediates according to the toxicity assessment of the identified products. This study provides a better understanding of the toxicity and metabolic mechanisms of benzophenone-3 in microalgae, demonstrating the potential application of microalgae in the remediation of benzophenone-3 contaminated wastewater.
Plants serve as appropriate markers of worldwide pollution because they are present in almost every corner of the globe and bioaccumulate xenobiotic chemicals from their environment. The potential of ...a semi-aquatic plant, Ipomoea aquatica, to uptake and metabolize sulfamethoxazole (SMX) was investigated in this study. I. aquatica exhibited 100% removal of 0.05 mg L−1 SMX from synthetic media within 30 h. The I. aquatica achieved 93, 77 and 72% removal of SMX at 0.2, 0.5 and 1 mg L−1, respectively, after 48 h. This indicated that removal efficiency of I. aquatica was deteriorating at high concentrations of SMX. The chlorophyll and carotenoid content of I. aquatica was insignificantly influenced by SMX irrespective of its high concentration. Similarly, scanning electron microscopy (SEM) showed that exposure to SMX had an insignificant impact on morphology of the plant organelles. The mechanisms of removal by I. aquatica were explored by evaluating contributions of bioadsorption, bioaccumulation and biodegradation. There was negligible adsorption of SMX to plant roots. Accumulation of SMX within plant roots and stems was not observed; however, I. aquatica accumulated 17% of SMX in leaves. Thus, the major mechanism of elimination of SMX was biodegradation, which accounted for 82% removal of SMX. Gas chromatography-mass spectrometry (GC-MS) confirmed that I. aquatica biodegraded SMX into simpler compounds, and generated 4-aminophenol as its final product. A laboratory scale phytoreactor was used to investigate the application of I. aquatica in a simulated system, where it achieved 49% removal of SMX (0.2 mg L−1) in 10 d.
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•I. aquatica exhibited 100% removal of 0.05 mg L−1 SMX from media within 30 h.•SMX had minor effects on the metabolism and physiology of I. aquatica.•The major mechanism of elimination of SMX by I. aquatica was biodegradation.•GC-MS confirmed that I. aquatica biodegraded SMX into simpler compounds.
The potential of Iris pseudacorus and the associated periphytic biofilm for biodegradation of two common pharmaceutical contaminants (PCs) in urban wastewater was assessed individually and in ...consortium. An enhanced removal for sulfamethoxazole (SMX) was achieved in consortium (59%) compared to individual sets of I. pseudacorus (50%) and periphytic biofilm (7%) at concentration of 5 mg L−1. Conversely, individual sets of periphytic biofilm (77%) outperformed removal of doxylamine succinate (DOX) compared to individual sets of I. pseudacorus (59%) and consortium (67%) at concentration of 1 mg L−1. Enhanced relative abundance of microflora containing microalgae (Sellaphora, Achnanthidium), rhizobacteria (Acidibacter, Azoarcus, Thioalkalivibrio), and fungi (Serendipita) in periphytic biofilm was observed after treatment. SMX treatment for five days elevated cytochrome P450 enzymes’ expressions, including aniline hydroxylase (48%) and aminopyrine N-demethylase (54%) in the periphytic biofilm. Nevertheless, I. pseudacorus showed 175% elevation of aniline hydroxylase along with other biotransformation enzymes, such as peroxidase (629%), glutathione S-transferase (514%), and dichloroindophenol reductase (840%). A floating bed phytoreactor planted with I. pseudacorus and the periphytic biofilm consortium removed 67% SMX and 72% DOX in secondary wastewater effluent. Thus, the implementation of this strategy in constructed wetland-based treatment could be beneficial for managing effluents containing PCs.
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•I. pseudacorus and associated biofilm synergistically improved removal of contaminants.•Acidibacter, Serendipita, Sellaphora in biofilm promotes plant growth.•Induction of phase I/II enzymes indicates their role in contaminants degradation.•Developed phytoreactor facilitated effective treatment of wastewater.
Engineered nanoparticles (ENPs) are advanced, high-throughput materials that have revolutionized almost every aspect of human life over the past decade with its numerous commercial applications ...across the globe. However, these particles have made their way into the environment through various pathways, eliciting unintended environmental consequences, and endangered various ecosystems and human health. Microalgae and their related microbial communities act as one of the key indicators of nano-toxicity, and play essential roles in bioremediation and bioenergy productions. In this review, we analyzed the interactions of nanoparticles with microalgae and the associated microbial communities along with its influence on the remediation capacities of pollutants such as organic pollutants, nitrogen and phosphorus. We also provide a comprehensive insight into the transcriptomics, proteomics and metagenomics of ENPs influenced microalgae and their related microbial communities to identify the in-depth protective and metabolic mechanisms. The information provided herein can extend the understanding of the effect of nanoparticles on environmental processes and might be useful in designing its disposal and treatment strategies.
Bisphenol S (BPS) acts as a xenoestrogen and disturbs the female reproductive system; however, the underlying mechanism has not been elucidated. In this study, the effect of chronic BPS exposure ...(1 μg/L and 100 μg/L) on ovarian lipid metabolism in zebrafish was investigated to determine its influence on adult reproductive capacity and offspring development. The results showed that long-term (240 days) exposure to BPS induced lipid accumulation in the ovaries by promoting the transport of more lipids from the circulation to the ovaries and by upregulating triacylglycerol synthesis-related genes. Significantly increased expression of cpt2, acadm, acadl, and pparα, which are involved in β-oxidation in the ovarian mitochondria, indicated that more energy was provided for oocyte maturation in exposed zebrafish ovaries. Thus, the proportion of full-grown stage oocytes in ovaries and egg reproduction were elevated at an accelerated rate, which earlier than normal reproductive cycle (8–10 days posts pawning). Moreover, the maternally BPS-exposed F1 embryos (2 h post-spawning, hpf) showed higher neutral lipid levels, impaired hatching capacity, and increased occurrence of larval deformities. All these findings demonstrated that stimulated lipid synthesis and β-oxidation in zebrafish ovaries significantly contribute to BPS-induced oocyte precociousness with subsequent effects on the development of unexposed offspring. This study provides new insight into the impact of xenoestrogens on oviparous reproduction in females and offspring development from the perspective of ovarian lipid metabolism.
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•Chronic toxicity of BPS on reproductive capacity of female zebrafish was studied.•Disrupted ovarian lipid metabolism can explain BPS promoted oocytes maturation.•Chronic BPS exposure subsequently induced formation of atretic follicle.•Maternal BPS exposure caused adverse effects on development of F1 generation.
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•The toxicity of cerium oxide nanoparticle on microalgae was evaluated.•Cerium oxide nanoparticle improved the transcripts of microalgal oxidoreductase.•Cerium oxide nanoparticle ...increased the removal of sulfonamides by microalgae.•Sulfadimethoxine was degraded by hydroxylation/dehydroxylation.
Nanoparticles have been commercially used worldwide; however, there is a lack of information of their environmental impacts and ecotoxicity. In this study, the effect of cerium oxide nanoparticle (CeO2NP) on a green microalga Scenedesmus obliquus, and microalgal biodegradation of four sulfonamides (sulfamethazine, sulfamethoxazole, sulfadiazine, and sulfamethoxazole) was investigated. There is insignificant inhibition of microalgal growth induced by CeO2NP; however, it substantially influenced the expression of genes involved in key cellular metabolic activities of S. obliquus. For example, genes involved in photosynthetic activity (psbA) and energy production (ATPF0C) were downregulated with exposure to CeO2NP. The low concentrations of CeO2NP improved microalgal degradation of sulfonamides. This may be because of the upregulated genes encoding hydrogenase and oxidoreductase. The exploration of this study has provided a new understanding of the environmental impacts of CeO2NP on microalgae-based biotechnologies for treatment of wastewater containing emerging organic contaminants.
•BPA, BPF, and T3 affected embryonic development and swim bladder inflation.•BPA, BPS, BPF, and T3 induced cardiotoxicity in zebrafish embryos.•BPA and BPF are hypothesized to cause cardiotoxicity ...via disrupting thyroid hormone metabolism relative-genes.
Bisphenols are frequently found in the environment and have been of emerging concern because of their adverse effects on aquatic animals and humans. In this study, we demonstrated that bisphenol A, S, and F (BPA, BPS, BPF) at environmental concentrations induced cardiotoxicity in zebrafish embryos. BPA decreased heart rate at 96 hpf (hours post fertilization) and increased the distance between the sinus venosus (SV) and bulbus arteriosus (BA), in zebrafish. BPF promoted heart pumping and stroke volume, shortened the SV-BAdistance, and increased body weight. Furthermore, we found that BPA increased the expression of the dio3b, thrβ, and myh7 genes but decreased the transcription of dio2. In contrast, BPF downregulated the expression of myh7 but upregulated that of thrβ. Molecular docking results showed that both BPA and BPF are predicted to bind tightly to the active pockets of zebrafish THRβ with affinities of -4.7 and -4.77 kcal/mol, respectively. However, BPS did not significantly affect dio3b, thrβ, and myh7 transcription and had a higher affinity for zebrafish THRβ (-2.13 kcal/mol). These findings suggest that although BPA, BPS, and BPF have similar structures, they may induce cardiotoxicity through different molecular mechanisms involving thyroid hormone systems. This investigation provides novel insights into the potential mechanism of cardiotoxicity from the perspective of thyroid disruption and offer a cautionary role for the use of BPA substitution.
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•80.5 % of doxylamine was degraded by T. angustifolia and I. aquatica.•Metabolic analysis confirmed degradation of doxylamine into simple intermediates.•An advanced phytobed was ...developed for efficient treatment of real wastewater.•Microbial community of the phytobed was analyzed to identify their functions.
Pharmaceutical contaminants in environment induce unexpected effects on ecological systems and human; thus, development of efficient technologies for their removal is immensely necessary. In this study, biodegradation and metabolic fate of a frequently found pharmaceutical contaminant, doxylamine by Typha angustifolia and Ipomoea aquatica was investigated. Microbial community of the plant rhizosphere has been identified to understand the important roles of the functional microbes. The plants reduced 48–80.5 % of doxylamine through hydrolysis/dehydroxylation and carbonylation/decarbonylation. A constructed phytobed co-planted with T. angustifolia and I. aquatica removed 77.3 %, 100 %, 83.67 %, and 61.13 % of chemical oxygen demand, total nitrogen, total phosphorus, and doxylamine respectively from real wastewater. High-throughput sequencing of soil and rhizosphere indicated that the phyla Proteobacteria, Bacteroidetes, Firmicutes, Planctomycetes, Actinobacteria, and Cyanobacteria dominated the microbial communities of the phytobed. Current study has demonstrated the applicability of the developed phytobeds for the treatment of doxylamine from municipal wastewater and provide a comprehensive understanding of its metabolism through plant and its rhizospheric microbial communities.
The preeminence of sulfonamide drug resistance genes in food waste (FW) and the increased utilization of high-strength organic FW in anaerobic digestion (AD) to enhance methane production have raised ...severe public health concerns in wastewater treatment plants worldwide. In this regard, the dissemination patterns of different sulfonamide resistance genes (sul1 and sul2) and their impact on the digester core microbiota during AD of FW leachate (FWL) were evaluated. The presence of various sulfonamide antibiotics (SAs) in FWL digesters improved the final methane yield by 37 % during AD compared with FWL digesters without SAs. Microbial population shifts towards hydrolytic, acidogenic, and acetogenic bacteria in the phyla Actinobacteriota, Bacteroidota, Chloroflexi, Firmicutes, Proteobacteria, and Synergistota occurred due to SA induced substrate digestion and absorption through active transport; butanoate, propanoate, and pyruvate metabolism; glycolysis; gluconeogenesis; the citrate cycle; and pentose phosphate pathway. The initial dominance of Methanosaeta (89–96 %) declined to 47–53 % as AD progressed and shifted towards Methanosarcina (40 %) in digesters with the highest SA concentrations at the end of AD. Dissemination of sul1 depended on class 1 integron gene (intl1)-based horizontal gene transfer to pathogenic members of Chloroflexi, Firmicutes, and Patescibacteria, whereas sul2 was transmitted to Synergistota independent of intl1. Low susceptibility and ability to utilize SAs during methanogenesis shielded methanogenic archaea against selection pressure, thus preventing them from interacting with sul or intl1 genes, thereby minimizing the risk of antibiotic resistance development. The observed emergence of cationic antimicrobial peptide, vancomycin, and β-lactam resistance in the core microbiota during AD of FWL in the presence of SAs suggests that multidrug resistance caused by bacterial transformation could lead to an increase in the environmental resistome through wastewater sludge treatment.
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•Cumulative methane yields enhanced by 37 % under SAs loading compared to FWL alone.•Methanosarcinales-led acetoclastic methanogenesis played a predominant role in methanation.•Dissemination of sul1 depended on intl1-based HGT.•Transmission of sul2 was intl1-independent.•Methanogenesis was uninterrupted by the influence of SAs or ARGs.
Pharmaceutical contamination in diverse water resources has been recognized as an emerging concern in environment because of its wide distribution and adverse effects on aquatic microorganisms and ...human health. Plant remediation with augmentation of microorganisms is a cost-effective and environmentally friendly approach toward an efficient treatment of pollutants, which can be easily applied in situ. (Bio)degradation of sulfamethazine (SMZ) by
Iris pseudacorus
, microalgal consortium, and plant–microalgal consortium was investigated.
I. pseudacorus
and microalgae could remove 63.5, and 25.8% of 1 mg SMZ L
−1
, respectively, whereas, the plant–microalgal consortium achieved 74% removal. The identified intermediates extracted after plant remediation indicated (bio)degradation of SMZ was through ring cleavage, hydroxylation, and dehydroxylation. Pigment content (total chlorophyll and carotenoid) of
I. pseudacorus
was significantly influenced by SMZ stress. A phytoreactor (20 L) constructed with
I. pseudacorus
achieved 30.0% and 71.3% removal of 1 mg SMZ L
−1
from tap water and nutrient medium. This study has provided a better understanding of the metabolic mechanisms of SMZ in plants and showed the potential development of a plant–microalgal consortium as an advanced technology for treatment of these emerging contaminants.
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