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1.
J Virol ; 97(11): e0048023, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37877715

RESUMO

IMPORTANCE: Viruses are able to mimic the physiological or pathological mechanism of the host to favor their infection and replication. Virus-mock basement membrane (VMBM) is a Megalocytivirus-induced extracellular structure formed on the surface of infected cells and structurally and functionally mimics the basement membrane of the host. VMBM provides specific support for lymphatic endothelial cells (LECs) rather than blood endothelial cells to adhere to the surface of infected cells, which constitutes a unique phenomenon of Megalocytivirus infection. Here, the structure of VMBM and the interactions between VMBM components and LECs have been analyzed at the molecular level. The regulatory effect of VMBM components on the proliferation and migration of LECs has also been explored. This study helps to understand the mechanism of LEC-specific attachment to VMBM and to address the issue of where the LECs come from in the context of Megalocytivirus infection.


Assuntos
Membrana Basal , Células Endoteliais , Iridoviridae , Vasos Linfáticos , Membrana Basal/metabolismo , Membrana Basal/virologia , Células Endoteliais/citologia , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Iridoviridae/fisiologia , Vasos Linfáticos/citologia , Proliferação de Células , Movimento Celular , Vasos Sanguíneos/citologia , Interações entre Hospedeiro e Microrganismos
2.
Fish Shellfish Immunol ; 98: 255-261, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31945486

RESUMO

Previous studies have indicated that white spot syndrome virus (WSSV) infection induces apoptosis in many shrimp organs. However, the mechanism by which WSSV causes host apoptosis remains largely unknown. In this study, we demonstrated the function of wsv152, the first mitochondrial protein identified as encoded by WSSV. Glutathione S-transferase pulldown and co-immunoprecipitation analysis revealed that wsv152 interacts with the shrimp mitochondrial protein cytochrome c oxidase 5a (COX5a), a subunit of the COX complex. We also found that wsv152 expression significantly increased the rate of apoptosis, suggesting a role of wsv152 in WSSV-induced apoptosis in shrimp. Knockdown of wsv152 in vivo led to downregulation of several apoptosis-related shrimp genes, including cytochrome c, apoptosis-inducing factor and caspase-3. Suppression of wsv152 also resulted in significant reductions in the number of WSSV genome copies in tissues and in the mortality of WSSV-infected shrimp. Together, these results suggest that wsv152 targets host COX5a and is associated with the expression profiles of apoptosis-related shrimp genes. Wsv152 is likely also involved in WSSV-induced apoptosis, thereby facilitating virus infection and playing a complex role in WSSV pathogenesis.


Assuntos
Apoptose/genética , Penaeidae/virologia , Proteínas Virais/metabolismo , Replicação Viral , Vírus da Síndrome da Mancha Branca 1/fisiologia , Animais , Proteínas de Artrópodes/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Hemócitos/metabolismo , Hemócitos/patologia , Interações Hospedeiro-Patógeno , Mitocôndrias/metabolismo , Penaeidae/metabolismo , Ligação Proteica , Taxa de Sobrevida , Carga Viral , Proteínas Virais/genética , Vírus da Síndrome da Mancha Branca 1/patogenicidade
3.
Fish Shellfish Immunol ; 84: 130-137, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30278220

RESUMO

Intestinal microbiota homeostasis is crucial to the health of host. Pathogen invasion results in dynamics of microbiota composition and structure, disrupting their function in maintaining host health. WSSV is the most prevalent viral pathogen and is able to cause extremely high mortality in Litopenaeus vannamei. However, the changes of intestinal microbiota induced by WSSV are yet to be elucidated. In this study, we analyzed and compared the microbiota of healthy and WSSV-challenged shrimp intestines. Though the richness and diversity of microbiota was barely affected by WSSV, the abundance of predominant phyla like Proteobacteria and Fusobacteria were upregulated significantly, while Bacteroidetes and Tenericutes were significantly decreased in WSSV-infected shrimps. At the genus level, significant increase was observed in Photobacterium, Propionigenium and Arcobacter, as well as significant decrease in Candidatus Bacilloplasma and Flavobacterium in WSSV-infected shrimps. Additionally, metagenomic predictions by PICRUSt suggested that the altered microbiota was mainly related to metabolism, human diseases, genetic information processing, environmental information processing and cellular processes. These results suggested that the invasion of WSSV could impact intestinal microbiota composition and function in L. vannamei.


Assuntos
Infecções por Vírus de DNA/microbiologia , Microbioma Gastrointestinal , Penaeidae/microbiologia , Vírus da Síndrome da Mancha Branca 1 , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Infecções por Vírus de DNA/veterinária , DNA Bacteriano/genética , RNA Ribossômico 16S/genética
4.
Fish Shellfish Immunol ; 93: 977-985, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31449979

RESUMO

C-type lectins (CTLs), which bind carbohydrates in a Ca2+-dependent manner, are involved in many cellular activities, especially immunity. CTLs play important roles in both the antibacterial and the antiviral immune response and are also associated with autoimmunity. Several CTLs have been investigated in crustaceans, primarily with respect to their function in the immune response. In this study, we cloned a novel CTL gene (LvCTLU) from Litopenaeus vannamei. LvCTLU is involved in microbe agglutination and phagocytosis. Downregulating LvCTLU increased the cumulative mortality of L. vannamei after Vibrio parahemolyticus infection. Similar to other reported CTLs, LvCTLU also had antiviral properties. Downregulation of LvCTLU also increased the cumulative mortality of L. vannamei after infection with white spot syndrome virus. More importantly, LvCTLU expression was induced by the unfolded protein response (UPR), which is the key pathway in the endoplasmic reticulum (ER)-stress response of eukaryotic organism. Our results suggested that this protein might be involved in the shrimp ER-stress response. Reporter gene assay indicated that LvCTLU was regulated by X-box-binding protein 1, which is the key transcription factor in the UPR. Our study thus revealed that LvCTLU plays vital roles in both the anti-pathogen immune response and the ER-stress response.


Assuntos
Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Penaeidae/genética , Penaeidae/imunologia , Proteína 1 de Ligação a X-Box/genética , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/imunologia , Sequência de Bases , Perfilação da Expressão Gênica , Lectinas Tipo C/química , Filogenia , Alinhamento de Sequência , Vírus da Síndrome da Mancha Branca 1/fisiologia , Proteína 1 de Ligação a X-Box/metabolismo
5.
Fish Shellfish Immunol ; 86: 1081-1087, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30593900

RESUMO

Antimicrobial peptides (AMPs) are small proteins showing broad-spectrum antimicrobial activity that have been known to be powerful agents against a variety of pathogens (bacteria, fungi and viruses). In this study, the effects of AMPs from Bacillus subtilis on Epinephelus coioides were examined. E. coioides were fed with diets containing AMPs (0, 100, 200, 400 or 800 mg/kg) for four weeks. Results showed that the levels of total protein (TP), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and blood glucose (GLU) and lipopolysaccharide (LPS) in the serum of E. coioides changed than those of the control group; compared to the control group, the levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and lysozyme (LZM) levels in E. coioides fed with different dosages AMP diets were also different; in addition, the mRNA expression of tumor necrosis factor alpha (TNF-α), interleukin-1-beta (IL-1ß), and heat shock protein 90 (Hsp90) in the tissues of E. coioides were measured, the three genes in the tissues examined were significantly upregulated. The results demonstrated that diets containing AMPs can enhance the antioxidant capacity and innate immune ability of E. coioides, indicating that AMPs might be a potential alternative to antibiotics in E. coioides.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Antioxidantes/metabolismo , Bass/imunologia , Imunidade Inata , Ração Animal/análise , Animais , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Bacillus subtilis/química , Bass/metabolismo , Análise Química do Sangue/veterinária , Dieta/veterinária
6.
Ecotoxicol Environ Saf ; 186: 109796, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31629908

RESUMO

The concentration of 8 antibiotics and 21 antibiotic resistance genes were investigated in the coastal areas of Guangdong, China. Total concentrations of antibiotics ranged from 0.43 ng/L to 1040.31 ng/L. The concentrations of tetracyclines were much higher than that of sulfonamides in most sampling sites. The abundance of target antibiotic resistance genes ranged from 1.82 × 105 to 5.9 × 109 copies/mL and tetM accounted for the highest percentages of detected antibiotic resistance genes in most sampling sites. Furthermore, the dominant phyla in water samples were Proteobacteria, Bacteroidetes and Actinobacteria. The relationship between antibiotics, antibiotic resistance genes, and bacterial communities was also investigated. As a result, the abundance of sul1 was positively correlated with the concentration of sulfadiazine, sulfamethoxazole and sulfonamide p-methyl oxypyrimidine. Besides, sulfonamide p-methyl oxypyrimidine, sulfadiazine and p-aminobenzenesulfonamide were significantly correlated with the bacterial communities. These findings suggested that the residues of antibiotics in coastal areas of Guangdong affect the distribution of antibiotic resistance genes and alter the microbial communities.


Assuntos
Antibacterianos/análise , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Microbiota , Poluentes Químicos da Água/análise , Bactérias/classificação , Bactérias/isolamento & purificação , China , Genes Bacterianos/genética , Microbiota/genética , Água do Mar/microbiologia , Microbiologia da Água
7.
World J Microbiol Biotechnol ; 34(7): 90, 2018 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-29886558

RESUMO

To search for more microbial resources for screening environment-friendly antifoulants, we investigated the phylogenetic diversity and antifouling potentials of culturable fungi in mangrove sediments from Techeng Isle, China. A total of 176 isolates belonging to 57 fungal taxa were recovered and identified. The high levels of diversity and abundance of mangrove fungi from Techeng Isle were in accordance with previous studies on fungi from other mangrove ecosystems. Fifteen of the 176 isolates demonstrated high divergence (87-93%) from the known fungal taxa in GenBank. Moreover, 26 isolates recorded in mangrove ecosystems for the first time. These results suggested that mangrove sediments from Techeng Isle harbored some new fungal communities compared with other mangrove ecosystems. The antifouling activity of 57 representative isolates (belonging to 57 different fungal taxa) was tested against three marine bacteria (Loktanella hongkongensis, Micrococcus luteus and Pseudoalteromonas piscida) and two marine macrofoulers (bryozoan Bugula neritina and barnacle Balanus amphitrite). Approximately 40% of the tested isolates displayed distinct antifouling activity. Furthermore, 17 fungal isolates were found to display strong or a wide spectrum of antifouling activity in this study, suggesting that these isolates deserve further study as potential sources of novel antifouling metabolites. To our knowledge, this is the first report on the investigation of the phylogenetic diversity and antifouling potential of culturable fungi in mangrove sediments from Techeng Isle, China. These results contribute to our knowledge of mangrove fungi and further increases the pool of fungi available for natural bioactive product screening.


Assuntos
Incrustação Biológica/prevenção & controle , Produtos Biológicos/farmacologia , Fungos/classificação , Fungos/isolamento & purificação , Fungos/metabolismo , Sedimentos Geológicos/microbiologia , Filogenia , Antibacterianos , Bactérias/efeitos dos fármacos , Biodiversidade , China , DNA Fúngico , Ecossistema , Fungos/genética , Água do Mar/microbiologia , Áreas Alagadas
8.
Virus Genes ; 52(2): 290-3, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26814812

RESUMO

White spot syndrome virus (WSSV) is a devastating pathogen of crustaceans that causes huge losses to global shrimp farming. In this study, a mitochondrial outer membrane protein encoded by WSSV, termed as wsv152, was identified. Bioinformatics analysis showed that wsv152 shared no similarity with any known proteins. Real-time RT-PCR revealed that wsv152 was initially transcribed at 6 h post WSSV infection. Fluorescent microscopy demonstrated that the wsv152-GFP fusion protein was present in the mitochondrion. Western blot further suggested that wsv152 was specifically localized on the outer membrane of mitochondria. To our knowledge, this is the first report of a mitochondrion-localized protein encoded by WSSV.


Assuntos
Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Membranas Mitocondriais/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Vírus da Síndrome da Mancha Branca 1/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Membrana/química , Fases de Leitura Aberta , Transporte Proteico , Proteínas do Envelope Viral/química
9.
J Virol ; 88(10): 5491-501, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24599992

RESUMO

UNLABELLED: Infectious spleen and kidney necrosis virus (ISKNV), the type species of the genus Megalocytivirus, family Iridoviridae, brings great harm to fish farming. In infected tissues, ISKNV infection is characterized by a unique phenomenon, in that the infected cells are attached by lymphatic endothelial cells (LECs), which are speculated to wall off the infected cells from host immune attack. A viral membrane protein, VP23R, binds and recruits the host nidogen-1 protein to construct a basement membrane (BM)-like structure, termed virus-mock basement membrane (VMBM), on the surface of infected cells to provide attaching sites for LECs. VMBMs do not contain collagen IV protein, which is essential for maintenance of BM integrity and functions. In this study, we identified the VP08R protein encoded by ISKNV. VP08R was predicted to be a secreted protein with a signal peptide but without a transmembrane domain. However, immunofluorescence assays demonstrated that VP08R is located on the plasma membrane of infected cells and shows an expression profile similar to that of VP23R. Coimmunoprecipitation showed that VP08R interacts with both VP23R and nidogen-1, indicating that VP08R is a component of VMBM and is present on the cell membrane by binding to VP23R. Through formation of intermolecular disulfide bonds, VP08R molecules self-organized into a multimer, which may play a role in the maintenance of VMBM integrity and stability. Moreover, the VP08R multimer was easily degraded when the ISKNV-infected cells were lysed, which may be a mechanism for VMBM disassembly when necessary to free LECs and release the mature virions. IMPORTANCE: Infectious spleen and kidney necrosis virus (ISKNV; genus Megalocytivirus, family Iridovirus) is most harmful to cultured fishes. In tissues, the ISKNV-infected cells are attached by lymphatic endothelial cells (LECs), which are speculated to segregate the host immune system. A viral membrane protein, VP23R, binds and recruits the host nidogen-1 protein to construct virus-mock basement membranes (VMBMs) on the surface of infected cells to provide attaching sites for LECs. Although VMBMs lack the collagen IV network, which is an essential structural part of true BMs, VMBMs still show an intact structure. An ISKNV-encoded VP08R protein can self-assemble into a multimer and bind both VP23R and nidogen-1 to maintain the integrity and stability of VMBMs. On the basis of these facts, we redrew the putative schematic illustration of the VMBM structure. Our study suggests that the virus adopts a strategy to remodel the cellular matrix and may provide an important reference to elucidate BM functions and the mechanisms of lymphangiogenesis.


Assuntos
Membrana Celular/química , Interações Hospedeiro-Patógeno , Iridoviridae/genética , Iridoviridae/fisiologia , Proteínas Estruturais Virais/análise , Proteínas Estruturais Virais/genética , Animais , Linhagem Celular , Imunoprecipitação , Microscopia de Fluorescência , Mapeamento de Interação de Proteínas , Multimerização Proteica
10.
Fish Shellfish Immunol ; 45(2): 443-53, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25917972

RESUMO

Death domain-associated factor 6 (Daxx) is a Fas-binding protein that mediates the activation of Jun amino-terminal kinase (JNK) pathway and Fas-induced apoptosis. In this study, a crustacean Daxx (LvDaxx) was firstly cloned and identified from Pacific white shrimp Litopenaeus vannamei. The LvDaxx cDNA was 2644 bp in length with an Open Reading Frame (ORF) of 2217 bp. Sequence analysis indicated that LvDaxx contained a single Daxx domain and two nuclear localization signals (NLSs) and shared a similarity with Drosophila melanogaster Daxx. LvDaxx was a nuclear-localized protein that was expressed highest in hemocytes and could be up-regulated in pathogen- and stimulant-challenge shrimps. LvDaxx could activate the artificial promoter containing an NF-κB binding site and the promoters of white spot syndrome virus (WSSV) ie1 gene and arthropod antimicrobial peptides (AMPs), suggesting LvDaxx could be involved in the activation of the NF-κB pathway. Knock-down of LvDaxx in vivo resulted in down-regulation of shrimp AMPs and reduction of WSSV copies in tissues. Furthermore, suppression of LvDaxx significantly decreased the mortality of WSSV-infected shrimps, but increased the mortality of Vibrio Parahaemolyticus-infected shrimps. Thus, these suggested that LvDaxx could play a role in the innate immunity against Vibrio parahaemolyticus in L. vannamei, while in the antiviral response, LvDaxx may be hijacked by WSSV and play a complex role in WSSV pathogenesis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Artrópodes , NF-kappa B/metabolismo , Proteínas Nucleares , Penaeidae , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/imunologia , Proteínas de Artrópodes/metabolismo , Sequência de Bases , Drosophila/genética , Dados de Sequência Molecular , Proteínas Nucleares/genética , Proteínas Nucleares/imunologia , Proteínas Nucleares/metabolismo , Penaeidae/genética , Penaeidae/imunologia , Penaeidae/metabolismo , Penaeidae/virologia , Interferência de RNA , Vírus da Síndrome da Mancha Branca 1
11.
Fish Shellfish Immunol ; 44(1): 26-32, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25659232

RESUMO

The Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway was known to participate in dozens of immune responses in organisms. Domeless, first identified in Drosophila melanogaster, is a unique receptor involved in invertebrate JAK/STAT pathway. In this study, a cytokine receptor (LvDOME) was identified in Litopenaeus vannamei. The LvDOME cDNA was 5178bp in length with an Open Reading Frame (ORF) of 4191bp. LvDOME contained two cytokine binding modules (CBMs) and three fibronectin-type-III-like (FNIII) domains, similar to most vertebrate IL-6 receptors. LvDOME was expressed highest in shrimp muscle and could be up-regulated in the late stage of white spot syndrome virus (WSSV) infection. LvDOME could significantly enhance the activity of the WSSV wsv069 gene promoter through acting on the STAT-binding motif, suggesting LvDOME could activate the JAK/STAT pathway. Moreover, knockdown of LvDOME resulted in lower cumulative mortality of shrimps and less WSSV copies, suggesting LvDOME may be hijacked by WSSV to benefit virus replication. To our knowledge, this is the first report on the receptor of JAK/STAT pathway in shrimp.


Assuntos
Proteínas de Artrópodes/genética , Penaeidae/genética , Penaeidae/imunologia , Receptores de Citocinas/genética , Transdução de Sinais , Vírus da Síndrome da Mancha Branca 1/fisiologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Regulação da Expressão Gênica , Dados de Sequência Molecular , Penaeidae/metabolismo , Filogenia , Receptores de Citocinas/química , Receptores de Citocinas/metabolismo
12.
J Hazard Mater ; 465: 133473, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38219586

RESUMO

Plastics are commonly used by society and their break down into millimeter-sized bits known as microplastics (MPs). Due to the possibility of exposure, reports of them in atmospheric deposition, indoor, and outdoor air have sparked worry for public health. In tropical and subtropical regions all throughout the world, mangroves constitute a distinctive and significant type of coastal wetlands. Mangrove plants are considered to have the effect of accumulating sediment MPs, but the sedimentation of atmospheric MPs has not been reported. In this study, we illustrated the characteristics, abundance and spatial distribution of MPs in different species of mangrove leaves along the Seagull Island in Guangzhou. MPs samples from leaves in five species showed various shapes, colors, compositions, sizes and abundance. Acanthus ilicifolius had an average fallout rate of 1223 items/m2/day which has the highest abundance of MPs in all samples. Four shapes of MPs were found in all leaves surfaces including fiber, fragment, pellet, and film, with fiber is the most. The dominant types of MPs in all leaves were cellulose and rayon. Most of the total MPs size were smaller than 2 mm. Clearly, the microstructures of each species leaf surfaces had an impact on its ability to retain MPs. The plants rough blade surfaces and big folds or gullies caused more particles to accumulate and had a higher MPs retention capacity. Overall, our study contributes to a better knowledge of the condition of MPs pollution in atmosphere and the connection between leaves structure and the retention of MPs, which indicates that mangrove plants are promising bioindicator of coastal atmospheric MPs pollution.


Assuntos
Microplásticos , Poluentes Químicos da Água , Plásticos , Biomarcadores Ambientais , Monitoramento Ambiental , Poluentes Químicos da Água/análise
13.
Food Chem ; 455: 139636, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38833871

RESUMO

Tea, sold as tea bags or loose tea, is a popular drink worldwide. We quantified microplastics in loose tea during various stages of production, from planting to processing and brewing. The quantity of microplastics in tea ranged from (70-3472 pcs/kg), with the highest abundance detected during processing, mainly in the rolling stage (2266 ± 1206 pcs/kg tea). Scanning electron microcopy revealed scratches and pits on the surface of microplastics fibers from tea plantation soil and processed tea, and their degradation was characterized by cracks and fractures. Exposure risks, based on an estimated dietary intake of 0.0538-0.0967 and 0.0101-0.0181 pcs /kg body weight /day for children and adults, respectively, are considered very low. This study not only evaluates the extent of research on microplastics pollution in tea, but also assess the risk of people's exposure to microplastics through drinking tea.


Assuntos
Exposição Dietética , Contaminação de Alimentos , Microplásticos , Chá , Chá/química , Exposição Dietética/análise , Microplásticos/análise , Contaminação de Alimentos/análise , Humanos , Camellia sinensis/química , Camellia sinensis/crescimento & desenvolvimento , Medição de Risco , Poluentes do Solo/análise , Poluentes do Solo/química
14.
Microorganisms ; 11(7)2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37512834

RESUMO

Plastic and microplastic pollution has caused a great deal of ecological problems because of its persistence and potential adverse effects on human health. The degradation of plastics through biological processes is of great significance for ecological health, therefore, the feasibility of plastic degradation by microorganisms has attracted a lot of attention. This study comprises a preliminary discussion on the biodegradation mechanism and the advantages and roles of different bacterial enzymes, such as PET hydrolase and PCL-cutinase, in the degradation of different polymers, such as PET and PCL, respectively. With a particular focus on their modes of action and potential enzymatic mechanisms, this review sums up studies on the biological degradation of plastics and microplastics related to mechanisms and influencing factors, along with their enzymes in enhancing the degradation of synthetic plastics in the process. In addition, biodegradation of plastic is also affected by plastic additives and plasticizers. Plasticizers and additives in the composition of plastics can cause harmful impacts. To further improve the degradation efficiency of polymers, various pretreatments to improve the efficiency of biodegradation, which can cause a significant reduction in toxic plastic pollution, were also preliminarily discussed here. The existing research and data show a large number of microorganisms involved in plastic biodegradation, though their specific mechanisms have not been thoroughly explored yet. Therefore, there is a significant potential for employing various bacterial strains for efficient degradation of plastics to improve human health and safety.

15.
Chemosphere ; 338: 139459, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37437614

RESUMO

With the rapid development of nanotechnology in the past decades, AgNPs are widely used in various fields and have become one of the most widely used nanomaterials, which leads to the inevitable release of AgNPs to the aquatic environment through various pathways. It is important to understand the effects of AgNPs on aquatic plants and zooplankton, which are widely distributed and diverse, and are important components of the aquatic biota. This paper reviews the effects of AgNPs on aquatic plants and zooplankton at the individual, cellular and molecular levels. In addition, the internal and external factors affecting the toxicity of AgNPs to aquatic plants and zooplankton are discussed. In general, AgNPs can inhibit growth and development, cause tissue damage, induce oxidative stress, and produce genotoxicity and reproductive toxicity. Moreover, the toxicity of AgNPs is influenced by the size, concentration, and surface coating of AgNPs, environmental factors including pH, salinity, temperature, light and co-contaminants such as NaOCl, glyphosate, As(V), Cu and Cd, sensitivity of test organisms, experimental conditions and so on. In order to investigate the toxicity of AgNPs in the natural environment, it is recommended to conduct toxicity evaluation studies of AgNPs under the coexistence of multiple environmental factors and pollutants, especially at natural environmental concentrations.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Animais , Zooplâncton , Prata/química , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/química , Plantas
16.
J Hazard Mater ; 443(Pt B): 130266, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36327848

RESUMO

Due to the small size, high mobility and large surface area, nanoplastics (NPs) showed high potential risks to aquatic organisms. This paper reviews the toxicity of NPs to aquatic organism at various trophic levels including bacteria, plankton (algae), zooplankton, benthos, and nekton (fish). The effects at individual level caused by NPs were explained and proved by cytotoxicity and genotoxicity, and the toxicity of NPs beyond individual level was also illustrated. The toxicity of NPs is determined by the size, dosage, and surface property of NPs, as well as environmental factors, the presence of co-contaminants and the sensitivity of tested organisms. Furthermore, the joint effects of NPs with other commonly detected pollutants such as organic pollutants, metals, and nanoparticles etc. were summarized. In order to reflect the toxicity of NPs in the real natural environment, studies on toxicity assessment of NPs with the coexistence of various environmental factors and contaminants, particularly under the concentrations in natural environment are suggested.


Assuntos
Poluentes Ambientais , Nanopartículas , Poluentes Químicos da Água , Animais , Organismos Aquáticos , Microplásticos , Nanopartículas/toxicidade , Peixes , Poluentes Químicos da Água/toxicidade
17.
Sci Total Environ ; 895: 165075, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37356768

RESUMO

Microplastics (MPs) contamination is widely found in marine organisms. Marine traditional Chinese medicines (MTCM) are derived from marine organisms, but there are no relevant reports on detecting MPs in MTCM. This study selected samples of MTCM from two representative pharmaceutical companies, Brand F and Brand Z, including mother-of-pearl, stone cassia, seaweed, pumice, oyster, kombu, calcined Concha Arcae, cuttlebone, and clam shell to detect and analyze the presence of MPs. The abundance, type, color, size, and composition of MPs were investigated. Varying degrees of MPs contamination was present in all MTCM. The abundance of MPs in different MTCM ranged from 0.07 to 9.53 items/g. Their type, color, and size are similar, mainly fiber, transparent and size <2 mm. The composition of MPs is primarily made of cotton, cellulose and rayon. This study contributes to the first record of MPs in MTCM. Our results show that microplastic pollution is common in MTCM, which may cause potential risk to patients consuming MTCM.


Assuntos
Microplásticos , Poluentes Químicos da Água , Humanos , Plásticos , Medicina Tradicional Chinesa , Poluentes Químicos da Água/análise , Monitoramento Ambiental
18.
Sci Total Environ ; 903: 166628, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37640084

RESUMO

Microplastics were frequently detected in the ocean, freshwater environment and wastewater treatment plants. This study aims to fill up the knowledge gap of microplastic distribution in nature reserves and scenery districts. Microplastic samples were collected, the distribution characteristics were analyzed with a stereoscopic microscope and a Fourier transform infrared spectrometer, and the ecological risks of microplastic pollution were calculated. Microplastics were detected in all the collected water samples and the average abundances of microplastics in the surface water of eleven investigated nature reserves and scenery districts ranged from 542 to 5500 items/m3. The degrees of microplastic pollution of all the surveyed nature reserves and scenery districts were classified as hazard level I. Fiber microplastics represented the largest average proportion (67.4 %) and 91.7 % of the detected microplastics were smaller than 2 mm. Corresponding to the frequent detection of fiber microplastics, cotton was the most abundant (25.5 %) polymer type of the suspected microplastics, followed by polyamide (PA, 20.6 %), polyester (PET, 17.0 %), and cellulose (15.6 %). For the ecological risk of the microplastic polymers, six, two and three nature reserves and scenery districts were defined to be at hazard level I, II and III, respectively. In brief, microplastic pollution occurred in all the surveyed nature reserves/scenery districts and posed different degrees of ecological risks.

19.
Chemosphere ; 340: 139809, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37579819

RESUMO

In this study, the occurrence and removal of ten selected antibiotics from aquaculture wastewater by the process solar + Fe(VI)+oxone were investigated. The detection levels of the antibiotics in the aquaculture wastewater samples were at ng/L. The degradation of the selected antibiotics under the process solar + Fe(VI)+oxone followed pseudo-first-order kinetics. As the most abundant antibiotic in the studied aquaculture wastewater, norfloxacin (NFX) was used as the model compound to study the reaction mechanism and detoxification ability of the treatment system, as well as the effects of reaction parameters and environmental factors. The active species including O2•-, O21, and Fe(V)/Fe(IV) contributed to NFX degradation in the process solar + Fe(VI)+oxone. Decarboxylation, the piprazine ring opening, defluorination of the benzene ring, oxygen addition and the cleavage of the quinolone/benzene ring were main degradation pathways of NFX. Around 20% mineralization was reached and the inhibition rate of the bacteria (Escherichia Coli) growth was reduced from 95.5% to 47.1% after the NFX degradation for 60 min. Despite the suppression of NFX degradation by NO2-, PO43- and humic acid, the NFX degradation in three aquaculture wastewater samples was faster than that in ultrapure water due to the positive effect of Br-and other factors. The above results demonstrate the treatment process solar-driven Fe(VI)/oxone has a good potential in antibiotics removal from the aquaculture wastewater.


Assuntos
Antibacterianos , Poluentes Químicos da Água , Águas Residuárias , Benzeno , Oxirredução , Norfloxacino , Aquicultura/métodos , Poluentes Químicos da Água/análise
20.
Sci Total Environ ; 905: 166880, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-37709097

RESUMO

Microplastics could act as vectors for the transport of harmful bacteria, such as pathogens and antibiotic resistance bacteria (ARB), but their combined effects have not been reported yet. Here, ARB Shigella flexneri with sulfonamides resistance and micro-polystyrene (micro-PS) were used to investigate their possible combined effects on the growth and expression of functional genes in Daphnia magna. Results showed that micro-PS colonized with S. flexneri were ingested by D. magna and blocked in their intestine after 24 h exposure. Changes were observed in the life history and morphology of D. magna, as well as the expression of functional genes in all treatments, but with no difference in the survival rate. We also determined the expression of six functional genes involved in energy and metabolism (arginine kinase, AK) and oxidative stress response (thioredoxin reductase, TRxR, catalase, CAT, and glutathione S-transferases, GSTs), as well as in growth, development and reproduction (vitellogenin, Vtg1 and ecdysone receptor, EcR). AK and Vtg1 did not show significant differences, however, EcR was down-regulated and the other three genes (TRxR, CAT, GSTs) were up-regulated in the combined-treated group. Antibiotic resistance gene (ARGs) sul1 was detected when exposed to micro-PS colonized with S. flexneri., suggesting that D. magna could acquire resistance genes through microplastic biofilms. These results indicated that MPs could act as a carrier of ARB to transfer ARGs into D. magna, and affect the life history, morphology, and the expression of related functional genes of D. magna, to adapt to the stress caused by MPs and ARB.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Microplásticos/metabolismo , Plásticos/metabolismo , Antibacterianos/toxicidade , Antibacterianos/metabolismo , Daphnia , Antagonistas de Receptores de Angiotensina/metabolismo , Antagonistas de Receptores de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/metabolismo , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Poliestirenos/metabolismo , Bactérias , Poluentes Químicos da Água/análise
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