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Aminophenyl sulfone compounds (ASCs) are widely used in various fields, such as the pharmaceutical and textile industries. ASCs and their primary acetylation products are inevitably discharged into the environment. However, the high toxicity of ASCs could be released from the deacetylation of acetylation products. Still, the occurrence and ecological risks of ASCs and their acetylation products remain largely unknown. Here, we integrated all of the existing ASCs based on the core structure, together with their potential acetylation products, to establish a database covering 1105 compounds. By combining the database with R programming, 45 ASCs, sulfonamides, and their acetylation products were identified in the influent and effluent of 19 municipal wastewater treatment plants in 4 cities of China. 13 of them were detected for the first time in the aquatic environment, and 12 acetylation products were newly identified. The cumulative concentrations of 45 compounds in the influent and effluent were in the range of 231-9.96 × 103 and 26-2.70 × 103 ng/L, respectively. The proportion of the unrecognized compounds accounted for 60.6% of the influent and 62.8% of the effluent. Furthermore, nearly half of the ASCs (46.7%), other sulfonamides (49.9%), and their acetylation products (46.2%) were discharged from the effluent, posing a low-to-medium risk to aquatic organisms. The results provide a guideline for future monitoring programs, particularly for sulfadiazine and dronedarone, and emphasize that the ecological risk of ASCs, sulfonamides, and their acetylation products needs to be considered in the aquatic environment.
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Sulfonamidas , Aguas Residuales , Contaminantes Químicos del Agua , Aguas Residuales/química , Sulfonamidas/análisis , Acetilación , Antibacterianos , Eliminación de Residuos Líquidos , China , Sulfonas , Monitoreo del AmbienteRESUMEN
Phaeodactylum tricornutum (Pt) is a critical microbial cell factory to produce a wide spectrum of marketable products including recombinant biopharmaceutical N-glycoproteins. N-glycosylation modification of proteins is important for their activity, stability, and half-life, especially some special modifications, such as fucose-modification by fucosyltransferase (FucT). Three PtFucTs were annotated in the genome of P. tricornutum, PtFucT1 was located on the medial/trans-Golgi apparatus and PtFucT2-3 in the plastid stroma. Algal growth, biomass and photosynthesis efficiency were significantly inhibited in a knockout mutant of PtFucT1 (PtFucT1-KO). PtFucT1 played a role in non-core fucose modification of N-glycans. The knockout of PtFucT1 might affect the activity of PtGnTI in the complex and change the complex N-glycan to mannose type N-glycan. The study provided critical information for understanding the mechanism of protein N-glycosylation modification and using microalgae as an alternative ecofriendly cell factory to produce biopharmaceuticals.
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Diatomeas , Fucosiltransferasas , Fucosiltransferasas/genética , Fucosiltransferasas/metabolismo , Diatomeas/genética , Diatomeas/metabolismo , Fucosa/metabolismo , Sistemas CRISPR-Cas , Proteínas Recombinantes/metabolismo , Polisacáridos/metabolismo , Aparato de Golgi/genética , Aparato de Golgi/metabolismo , Galactósido 2-alfa-L-FucosiltransferasaRESUMEN
There is growing evidence that the transformation products of emerging contaminants in foodstuffs may pose a health risk to humans. However, the exact identities, levels, and estimated dietary intake (EDI) of neonicotinoid transformation products in crops remain poorly understood. We established an extended suspect screening strategy to investigate neonicotinoid insecticides and their transformation products in retail cowpea from 11 cities in Hainan Province, China. Forty-nine transformation products were identified in retail cowpea, of which 22-36 were found in 98.6% of the samples. Notably, 31 new transformation products were derived from new processes or a combination of different transformation processes. The mean concentrations of neonicotinoids and nine of the transformation products (with authentic standards) were in the ranges of 0.0824-5.34 and 0.0636-1.50 ng/g, respectively. The cumulative EDIs of the quantified transformation products were lower than those of parent neonicotinoids with the exception of clothianidin desmethyl, which had a ratio of 1157%. However, the coexistence of the other 40 transformation products (without authentic standards) in cowpea suggested that the exposure risk from all of the transformation products might be higher. This study demonstrated that pesticide transformation products should be considered in food chain risk assessments and included in future regulatory management.
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Insecticidas , Vigna , Humanos , Neonicotinoides , Productos Agrícolas , China , NitrocompuestosRESUMEN
Pollution by chemicals and waste impacts human and ecosystem health on regional, national, and global scales, resulting, together with climate change and biodiversity loss, in a triple planetary crisis. Consequently, in 2022, countries agreed to establish an intergovernmental science-policy panel (SPP) on chemicals, waste, and pollution prevention, complementary to the existing intergovernmental science-policy bodies on climate change and biodiversity. To ensure the SPP's success, it is imperative to protect it from conflicts of interest (COI). Here, we (i) define and review the implications of COI, and its relevance for the management of chemicals, waste, and pollution; (ii) summarize established tactics to manufacture doubt in favor of vested interests, i.e., to counter scientific evidence and/or to promote misleading narratives favorable to financial interests; and (iii) illustrate these with selected examples. This analysis leads to a review of arguments for and against chemical industry representation in the SPP's work. We further (iv) rebut an assertion voiced by some that the chemical industry should be directly involved in the panel's work because it possesses data on chemicals essential for the panel's activities. Finally, (v) we present steps that should be taken to prevent the detrimental impacts of COI in the work of the SPP. In particular, we propose to include an independent auditor's role in the SPP to ensure that participation and processes follow clear COI rules. Among others, the auditor should evaluate the content of the assessments produced to ensure unbiased representation of information that underpins the SPP's activities.
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Conflicto de Intereses , Ecosistema , Humanos , Contaminación Ambiental , BiodiversidadRESUMEN
The mechanisms of phylogenetic turnover of microbial communities to environmental perturbations in sediments remain unclear. In this study, the molecular mechanisms of phylogenetic turnover, and impact of antibiotics and antibiotic resistance genes (ARGs) on the modification of microbial assemblages were unravelled. We investigated 306 ARGs, 8 transposases, and 4 integron integrases, bacteria, and eukaryotic diversity through high-throughput quantitative PCR and illumina sequencing, 21 antibiotics and 3 tetracycline byproducts. The freshwater and estuary ecosystems were mainly dominated by genus Sulfurovum and colonised by closely related species compared with the estuary (closeness centrality = 0.42 vs. 0.46), which was dominated by genus Mycobacterium. Eighty-six percent of the ecological process in the bacterial community was driven by stochastic processes, while the rest was driven by deterministic processes. Environmental-related concentrations of antibiotics (0.15-32.53 ng/g) stimulated the proliferation of ARGs which potentially modulated the microbial community assembly. ARG acquisition significantly (P < 0.001) increased eukaryotic diversity through protection mechanisms. ARGs showed complex interrelationships with the microbial communities, and phylum arthropods and Nematea demonstrated the strongest ARG acquisition potential. This study provides key insights for environmental policymakers into understanding the ecological impact of antibiotics and the role of ARGs in modulating the phylogenetic turnover of microbial communities and trophic transfer mechanisms.
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Antibacterianos , Microbiota , Antibacterianos/farmacología , Antibacterianos/análisis , Genes Bacterianos , Filogenia , ARN Ribosómico 16S/genética , Farmacorresistencia Bacteriana , Biodiversidad , Bacterias/genéticaRESUMEN
The discharge of antibiotics and metals in estuaries is of great concern since they threaten microbial communities that are critical for maintaining ecosystem function. To understand single and combined effects of norfloxacin (0-20 µg g-1) and copper (40 µg g-1) on microbial ecology in estuaries, we evaluated changes in bacteria population, inhibition rates, and microbial composition in estuarine sediments over a 28-day period. Bacteria population significantly decreased following single and combined exposure to norfloxacin and copper throughout the incubation period, except on Day 28 in treatments exposed to copper, 20 µg g-1 norfloxacin, or both. These three treatment groups had lower Shannon diversity and Simpson's indices on Day 28 than other treatments and the controls suggesting recovery in bacteria population did not correspond with recovery in richness and evenness. Furthermore, functional predictions revealed that the effect of time and contaminants were significantly different on some microbial community functions on Day 28, especially the combination of Cu and high concentration NFX, including aerobic chemoheterotrophy, methanol oxidation and methylotrophy. Thus, norfloxacin and copper had significant adverse effects on microbial communities in estuarine sediments; however, the combined effects were variable and depended on exposure duration and antibiotic concentration.
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Cobre , Microbiota , Bacterias , Cobre/toxicidad , Estuarios , Sedimentos Geológicos , NorfloxacinoRESUMEN
With development of e-waste related legislation in China, formal recycling activities are designated in some areas while informal ones are illegally transferred to emerging areas to avoid supervision. However, the resulting environmental impact and ecological risks are not clear. Here, we investigated the discharge of polychlorinated biphenyls (PCBs) to soil and aquatic environments by e-waste recycling activities in the Lian River Basin, China. The study area included a designated industrial park in the traditional e-waste recycling area (Guiyu, known as the world's largest e-waste center), several emerging informal recycling zones, and their surrounding areas and coastal area. A total of 27 PCBs were analyzed, and the highest concentration was found in an emerging site for soil (354 ng g-1) and in a traditional site for sediment (1350 ng g--1) respectively. The pollution levels were significantly higher in both the traditional and emerging recycling areas than in their respective upstream countryside areas (p = 0.0356 and 0.0179, respectively). Source analysis revealed that the traditional and emerging areas had similar PCB sources mainly associated with three PCB technical mixtures manufactured in Japan (KC600) and the USA (Aroclor 1260 and Aroclor 1262). The PCB pollution in their downstream areas including the coastal area was evidently affected by the formal and informal recycling activities through river runoff. The ecological risk assessments showed that PCBs in soils and sediments in the Lian River Basin could cause adverse ecotoxicological consequences to humans and aquatic organisms.
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Residuos Electrónicos , Bifenilos Policlorados , China , Residuos Electrónicos/análisis , Monitoreo del Ambiente/métodos , Humanos , Bifenilos Policlorados/análisis , Reciclaje , Ríos , SueloRESUMEN
The outbreak of the human coronavirus disease 2019 (COVID-19) has induced an unprecedented increase in the use of several old and repurposed therapeutic drugs such as veterinary medicines, e.g. ivermectin, nonsteroidal anti-inflammatory drugs, protein and peptide therapeutics, disease-modifying anti-rheumatic drugs and antimalarial drugs, antiretrovirals, analgesics, and supporting agents, e.g. azithromycin and corticosteroids. Excretion of drugs and their metabolites in stools and urine release these drugs into wastewater, and ultimately into surface waters and groundwater systems. Here, we review the sources, behaviour, environmental fate, risks, and remediation of those drugs. We discuss drug transformation in aquatic environments and in wastewater treatment systems. Degradation mechanisms and metabolite toxicity are poorly known. Potential risks include endocrine disruption, acute and chronic toxicity, disruption of ecosystem functions and trophic interactions in aquatic organisms, and the emergence of antimicrobial resistance.
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Understanding the occurrence, behavior, and fate of potentially toxic elements (PTEs) in the substrate-mushroom-human nexus is critical for assessing and mitigating their human health risks. In this review, we (1) summarized the nature, sources, and biogeochemical behavior of PTEs in the substrate-mushroom systems; (2) discussed the occurrence, exposure, and human health risks of PTEs in mushrooms with emphasis on African geological hotspots such as metalliferous and highly mineralized substrates; (3) developed a 10-step conceptual framework for identifying, assessing, and mitigating the human health risks of PTEs in mushrooms, and highlight future directions. High human exposure risks potentially exist in Africa due to the following: (1) widespread consumption of mushrooms from various metalliferrous and highly mineralized substrates such as serpentines and mine waste dumps, (2) inadequate and poorly enforced environmental health and food safety regulations and policies, (3) limited environmental and human health monitoring data, and (4) potential synergistic interactions among PTEs in mushrooms and human health stressors such as a high burden of human diseases and infections. Although the human health effects of individual PTEs are well known, scientific evidence linking human health risk to PTEs in mushrooms remains weak. A framework for risk assessment and mitigation, and future research directions are recommended.
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Agaricales , Metales Pesados , Contaminantes del Suelo , África , Monitoreo del Ambiente , Humanos , Metales Pesados/análisis , Medición de Riesgo , Contaminantes del Suelo/análisisRESUMEN
The assumption that only biological processes are enantioselective introduces challenges in the reliability of enantioselective analysis as a tool for discriminating biotic and abiotic processes in the environmental fate of chiral pollutants. Enantioselectivity does not depend on the nature of the fate process a chiral contaminant undergoes but on the interaction of the chiral contaminant with homochirality inducing external agents (e.g. chiral molecules, macromolecules or surfaces such as enzymes, blood plasma, proteins, chiral co-pollutants, humic acid and soil organominerals). The environmental behavior of a chiral contaminant is difficult to anticipate because the interactions between the chiral contaminants and the homochirality inducing external agents is often complex and strongly influenced by local environment conditions such as pH, redox conditions, organic carbon, organic nitrogen, humic acid, and redox conditions. Furthermore, the use of enantioselective analysis in environmental forensics depend on the adequate separation and accurate identification and quantification of the enantiomers of the chiral contaminant. Matrix effects, instrument effects, inadequate enantioselective separation, and poor quantification techniques introduce uncertainties in the determination of enantiomeric composition. Here we present the weaknesses of this assumption and recommend using enantiomeric fractions as chemical markers of biotransformation with caution. We recommend using stable isotopes, including abiotic controls to determine if enantioselective sorption occurs, and determining stability of enantiomers in solvent or at elevated temperatures to account for confounding factors arising from matrix effects, enantioselective abiotic processes, and enantiomerization due solvent and thermal lability of the chiral analyte, respectively to maintain the integrity of the utility of enantiomeric composition changes as an environmental forensics tool.
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Contaminantes Ambientales , Biotransformación , Reproducibilidad de los Resultados , Suelo , EstereoisomerismoRESUMEN
Microplastics have a strong affinity for potentially toxic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). Since 2005, the International Pellet Watch used plastic pellets to monitor hydrophobic organic contaminants in marine environments. We examined the spatial distribution and sources of 16 PAHs and eight OCPs on microplastics (pellets, fragments, and foam) collected from eastern Guangdong beaches with the goal of evaluating the feasibility of exclusively using pellets in global monitoring of hydrophobic organic contaminants. The ∑PAH and ∑OCP concentrations ranged from 11.2 to 7710 ng g-1 and 2.2-1970 ng g-1, respectively. Although inter-site and regional differences were insignificant in fragments and foam, regional differences were observed in ∑OCP concentrations on pellets samples collected at the estuary mouth and the distributary (p < 0.05). No regional difference in ∑PAH concentration on microplastics was observed, except between fragments from the remote beach and those from the distributary (p = 0.015) and the estuary mouth (p = 0.015). The compositional profiles of PAHs revealed that PAHs with 2-4 rings were more dominant than those with >4 rings. Considering low molecular weight PAHs are less hydrophobic and more toxic; the results suggest low molecular weight PAHs may pose a significant risk to marine organisms. This study shows that the International Pellet Watch could offer critical data on source and transport of microplastic-associated OCPs but may overlook critical vehicles of PAHs in coastal environments such as foam.
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Sedimentos Geológicos/química , Hidrocarburos Clorados/análisis , Microplásticos , Plaguicidas/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Playas , Monitoreo del Ambiente , EstuariosRESUMEN
Nearshore ecosystems are transitional zones, and they may harbor a diverse microbial community capable of degrading azo dyes under extreme environmental conditions. In this study, thirteen bacterial strains capable of degrading eight azo dyes were isolated in nearshore environments and characterized using high throughput 16 S rRNA sequencing. The results of this study demonstrate that the biodegradability of azo dyes was influenced by their chemical structure and position of functional groups as well as the type of bacteria. The decolorization rate of Methyl Orange (95%) was double that of the heavier and sterically hindered Reactive Yellow 84 (<40%). Shewanella indica strain ST2, Oceanimonas smirnovii strain ST3, Enterococcus faecalis strain ST5, and Clostridium bufermentans strain ST12 demonstrated potential application in industrial effluent treatment as they were tolerant to a wide range of environmental parameters (pH: 5-9, NaCl: 0-70 g L-1, azo dye concentration: 100-2000 mg L-1) including exposure to metals. Analysis of the transformation products using GC-MS revealed that different bacterial strains may have different biotransformation pathways. This study provides critical insight on the in-situ biotransformation potential of azo dyes in marine environments.
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Colorantes , Industria Textil , Compuestos Azo , Biodegradación Ambiental , EcosistemaRESUMEN
Azo dyes are widely used in the textile industry despite being poorly biodegradable and highly toxic. Hence, azo dyes need to be removed from effluent prior to environmental discharge. Microbial communities are efficient for the degradation and mineralization of azo dyes. However, little is known about the functional microbial communities responsible for the degradation process. In this study, a novel indigenous bacteria consortium was developed for characterizing the functional microbial communities involved in the degradation of a sulfonated azo dye, Direct Blue 2B (DB2) in a simple batch reactor. The optimal temperature, pH, and salinity for the decolorization process were 38.70⯰C, pH 7.57, and 20.10â¯gâ¯L-1 NaCl, respectively. The effect of the operating conditions on microbial community structure were determined using high-throughput Illumina HiSeq sequencing. Gammaproteobacteria, Betaproteobacteria, and Bacilli were dominant under most of the operating conditions. At pH above 8 and NaCl concentration above 30â¯gâ¯L-1, Firmicutes relative abundance did not significantly change suggesting tolerance towards alkaline and hypersaline environments. Tritium aestivum and Glycine max seed germination following exposure to YHK treated DB2 solution was above 80% compared to 50% in untreated DB2 solution. The YHK consortium decolorized dyes structurally different from DB2 such as trimethyl phenyl and direct dyes. The results of this study offer valuable data on improving optimization of dye biodegradation processes and the capability of YHK in in situ bioremediation.
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Compuestos Azo , Industria Textil , Bacterias , Biodegradación Ambiental , ColorantesRESUMEN
Sugarcane and bioethanol production produces large amounts of bagasse fly ash and vinasse, which are solid and viscous liquid wastes, respectively. However, these wastes are often disposed into the environment without treatment, thus posing an environmental and public health risk. This study investigated the treatment of vinasse effluent in terms of reduction of chemical oxygen demand (COD) and acidity removal using sugarcane bagasse fly ash. A maximum COD removal efficiency of 72% was obtained using an effluent volume of 100â¯mL, contact time of 180â¯min, and shaking speed of 240â¯rpm. The adsorbent dose and particle sizes were 4.5â¯g and 90-125⯵m, respectively. Furthermore, the potential application of bagasse fly ash as an adsorbent in a sand filtration bed was assessed using a column test. A maximum recovery of 68% was obtained at the 25-min interval. The adsorption data was found to fit the Freundlich model best (Kfâ¯=â¯2.16â¯mgâ¯g-1; R2â¯=â¯0.96), and the kinetics fit the pseudo-second order model (R2â¯=â¯0.98).
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Celulosa , Saccharum , Contaminantes Químicos del Agua/química , Adsorción , Carbono , Ceniza del Carbón , CinéticaRESUMEN
Non-targeted analysis and suspect screening of per- and polyfluoroalkyl substances (PFAS) in various matrices have gained traction with advancements in accurate mass analytical instruments. This study employed ultra-high performance liquid chromatography coupled to quadrupole orbitrap high-resolution mass spectrometry for PFAS suspect screening of paper grades used in the paper recycling chain. The samples were prepared using two extraction techniques; selective accelerated solvent extraction with weak anionic exchange solid-phase extraction and non-selective ultrasonic-assisted extraction. A suspect screening protocol was established to tentatively identify suspected PFAS against spectral databases using a systematic approach of peak filtering and study-specific thresholds for reporting, linked to a confidence level. The possible prevalence of previously unreported PFAS in several paper materials across the various collection sites in the paper recycling chain was inferred by the common detection of short-chain polyfluoroalkyl ketones and diketones in the paper recycling chain. The suspect screening tentatively identified 41 unique PFAS, with 3 common to both pre-treatment techniques. The detection of unique PFAS by the two sample pre-treatment techniques highlighted the significance of both selective and non-selective extraction in PFAS screening endeavours. Further, it showed the importance of understanding the acquisition mechanisms employed in mass spectrometry where data-dependent acquisition triggered fragmentation in certain identified compounds, and not in others. The tentatively identified PFAS indicated that there were several previously unreported PFAS in the paper recycling chain and that additional studies were required to investigate their abundance, possible persistence, bioaccumulation and toxicity, in relation to their functional groups and carbon chains.
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Globally, per- and polyfluoroalkyl substances (PFAS)-related research on paper products has focused on food packaging with less consideration on the presence of PFAS at different stages of the paper recycling chain. This study analysed the prevalence of PFAS in paper grades used for the manufacture of recycled paperboard. The presence of PFAS was attributed to the use of PFAS-containing additives, consumer usage, exposure to packed goods as well as contamination during mingling, sorting, collection, and recovery of paper recycling material. Q Orbitrap mass spectrometry was used to analyse the paper samples after accelerated solvent extraction and solid phase extraction. The distribution and possible propagation of 22 PFAS were determined in pre-consumer, retail and post-consumer paper products. Post-consumer samples had the highest combined average concentration (ΣPFAS) at 213 ng/g, while the ΣPFAS in retail (159 ng/g) and pre-consumer samples (121 ng/g) was detected at lower concentrations. This study showed that waste collection and recycling protocols may influence PFAS propagation and that measures must be developed to minimise and possibly eliminate exposure opportunities.
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Fluorocarburos , Espectrometría de Masas , Papel , Reciclaje , Fluorocarburos/análisis , Cromatografía Líquida de Alta Presión , Extracción en Fase SólidaRESUMEN
Exposure to pesticides can pose a series of advance effects on human health. However, the exposure levels and health implications of the current use pesticides and their metabolites in both men and pregnant women remain unclear. In this study, an analytical method was developed to quantify fungicides, neonicotinoid insecticides, triazine herbicides, and their metabolites in the human serum. Fifty of the 73 target pesticides and metabolites were detected in the human serum of men and pregnant women from Wuxi, China, which included 11 triazine herbicides and metabolites, 17 neonicotinoid insecticides and metabolites, and 22 fungicides. Fungicides had the highest cumulative concentration (49.5 ng/mL), followed by neonicotinoid insecticides and metabolites (6.38 ng/mL), and triazine herbicides and metabolites (5.10 ng/mL). Moreover, the estimated daily intake (EDI) of fungicides was 10.4 and 12.7 times higher than that of triazine herbicides (included their metabolites) and neonicotinoid insecticides (included their metabolites), respectively. Of the three categories of pesticides, exposure to fungicides contributed to the highest exposure risk within the hazard quotient in the range of 5.1 × 10-3-0.17. Correlation analysis revealed that the pesticide exposure levels in human serum were correlated with their maximum residue levels in vegetables and fruits. Pesticide exposure has also been correlated with the weight and Body Mass Index (BMI) of humans based on structural equation modeling. This study provides new insights into the exposure of men and pregnant women to a cocktail of fungicides, neonicotinoid insecticides, triazine herbicides and their metabolites.
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Fungicidas Industriales , Herbicidas , Insecticidas , Plaguicidas , Masculino , Humanos , Femenino , Embarazo , Insecticidas/análisis , Mujeres Embarazadas , Plaguicidas/análisis , Neonicotinoides , TriazinasRESUMEN
The emergence and dissemination of antibiotic resistance genes (ARGs) in the ecosystem are global public health concerns. One Health emphasizes the interconnectivity between different habitats and seeks to optimize animal, human, and environmental health. However, information on the dissemination of antibiotic resistance genes (ARGs) within complex microbiomes in natural habitats is scarce. We investigated the prevalence of antibiotic resistant bacteria (ARB) and the spread of ARGs in intensive bullfrog (Rana catesbeiana) farms in the Shantou area of China. Antibiotic susceptibilities of 361 strains, combined with microbiome analyses, revealed Escherichia coli, Edwardsiella tarda, Citrobacter and Klebsiella sp. as prevalent multidrug resistant bacteria on these farms. Whole genome sequencing of 95 ARB identified 250 large plasmids that harbored a wide range of ARGs. Plasmid sequences and sediment metagenomes revealed an abundance of tetA, sul1, and aph(3â³)-Ib ARGs. Notably, antibiotic resistance (against 15 antibiotics) highly correlated with plasmid-borne rather than chromosome-borne ARGs. Based on sequence similarities, most plasmids (62%) fell into 32 distinct groups, indicating a potential for horizontal plasmid transfer (HPT) within the frog farm microbiome. HPT was confirmed in inter- and intra-species conjugation experiments. Furthermore, identical mobile ARGs, flanked by mobile genetic elements (MGEs), were found in different locations on the same plasmid, or on different plasmids residing in the same or different hosts. Our results suggest a synergy between MGEs and HPT to facilitate ARGs dissemination in frog farms. Mining public databases retrieved similar plasmids from different bacterial species found in other environmental niches globally. Our findings underscore the importance of HPT in mediating the spread of ARGs in frog farms and other microbiomes of the ecosystem.
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The tissue distribution (liver, kidney, heart, lung, and muscle), source, and trophic transfer of 15 polycyclic aromatic hydrocarbons (PAHs) were studied on 14 stranded East Asian finless porpoises (Neophocaena asiaeorientalis sunameri), 14 spotted seals (Phoca largha), and 9 stranded minke whales (Balaenoptera acutorostrata) from Yellow Sea and Liaodong Bay. The PAHs levels ranged from below the limit of detection to 459.22 ng g-1 dry weight in the tissues of the three marine mammals, and light molecular weight PAHs were the primary pollutants. Although the PAHs levels were relatively higher in internal organs of the three marine mammals, generally no tissue-specific distribution of the PAHs congeners was found, either for gender-specific distribution of PAHs in the East Asian finless porpoises. However, species specific PAHs concentration distribution were obtained. The PAHs were mainly originated from petroleum and biomass combustion in the East Asian finless porpoises, while those for the spotted seals and minke whales were complex. Trophic level associated biomagnification was found for phenanthrene, fluoranthene, and pyrene in the minke whale. Benzo(b)fluoranthene exhibited a significant biodilution with increasing trophic levels in the spotted seals, but the total concentration of the PAHs showed a significant biomagnification with increasing trophic levels. Trophic level-associated biomagnification of acenaphthene, phenanthrene, anthracene, and ∑PAHs were found in the East Asian finless porpoise, while pyrene exhibited obvious biodilution with increasing trophic levels. Our current study filled knowledge gaps on tissue distribution and trophic transfer of the PAHs in the investigated three marine mammals.