The microbial communities colonized on microplastics(MPs)have attracted widespread attention.However,few studies focused on the MPs impacts on mangrove ecosystems,particularly on bacterial communities.We investigated ...The microbial communities colonized on microplastics(MPs)have attracted widespread attention.However,few studies focused on the MPs impacts on mangrove ecosystems,particularly on bacterial communities.We investigated the MPs pollution in mangrove of Zhujiang(Pearl)River estuary(ZRE).To study the potential risk posed by MPs to the mangrove ecosystems,the differences in bacterial communities,functions,and complexity between MPs and sediment samples were reported for the first time.Microplastics(2991±1586 items/kg dry weight(dw))in sediment were mainly fibers and polyethylene,mostly transparent,and in size less than 0.5 mm.Bacterial communities and functions significantly differed from MPs in mangrove sediment.Compared with sediment,MPs significantly enriched members of Proteobacteria,Bacteroidetes,and Actinobacteria,as well as the bacteria associated with plastic-degrading and human diseases on their surface,suggesting that microbial communities on MPs may promote MPs degradation and the spread of diseases,posing potential risk to mangrove ecosystems and human health.Although bacteria on MPs exhibited a lower diversity,the co-occurrence network analysis indicated that network of bacteria colonized on MPs was bigger and more complex than those of mangrove sediment,illustrating that MPs can act as a distinct habitat in this special ecosystem.This study provides a new perspective for increasing our understanding of microplastic pollution in mangrove ecosystems.展开更多
In this study,bismuth ferrite(BiFeO_(3),BFO)catalysts doped with different contents of peanut shell biochar(BC)were prepared and used in the removal of antibiotic-resistant bacteria(ARB)by peroxymonosulfate(PMS)activa...In this study,bismuth ferrite(BiFeO_(3),BFO)catalysts doped with different contents of peanut shell biochar(BC)were prepared and used in the removal of antibiotic-resistant bacteria(ARB)by peroxymonosulfate(PMS)activation from wastewater.The PMS(0.03 mM)/5%BC-BFO(0.5 g L^(−1))system removed 1.92 log ARB within 10 min of reaction at a reaction rate of 0.4401 min^(−1).Raman spectra analysis revealed that 5%BC-BFO exhibited more defects and oxygen vacancies(Ov),which provided active sites for PMS activation to generate SO_(4)^(⋅−),O_(2)^(⋅−),and^(1)O_(2),thereby promoting ARB inactivation.The oxidation of PMSO to PMSO₂suggests that high-valent iron-oxo species may also be involved in the inactivation of ARB.The PMS/5%BC-BFO system caused oxidative damage to the ARB cell membrane,increasing its permeability from 4.34%to 46.00%.Simultaneously,it triggered the activation of bacterial self-defense mechanisms and a cascade reaction,leading to the upregulation of intracellular reactive oxygen species(ROS)levels(rising from 6.34%to 62.90%),ultimately resulting in ARB inactivation.In addition,the ARB removal under PMS activation by the fourth recycled 5%BC-BFO catalyst was 62.6%of that by the fresh 5%BC-BFO.In summary,this study proposes a low-cost and easily synthesized novel catalyst for the efficient ARB removal from wastewater.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.42177253,41807476,41706186)Natural Science Foundation of Guangdong Province,China(No.2022A1515010197)。
文摘The microbial communities colonized on microplastics(MPs)have attracted widespread attention.However,few studies focused on the MPs impacts on mangrove ecosystems,particularly on bacterial communities.We investigated the MPs pollution in mangrove of Zhujiang(Pearl)River estuary(ZRE).To study the potential risk posed by MPs to the mangrove ecosystems,the differences in bacterial communities,functions,and complexity between MPs and sediment samples were reported for the first time.Microplastics(2991±1586 items/kg dry weight(dw))in sediment were mainly fibers and polyethylene,mostly transparent,and in size less than 0.5 mm.Bacterial communities and functions significantly differed from MPs in mangrove sediment.Compared with sediment,MPs significantly enriched members of Proteobacteria,Bacteroidetes,and Actinobacteria,as well as the bacteria associated with plastic-degrading and human diseases on their surface,suggesting that microbial communities on MPs may promote MPs degradation and the spread of diseases,posing potential risk to mangrove ecosystems and human health.Although bacteria on MPs exhibited a lower diversity,the co-occurrence network analysis indicated that network of bacteria colonized on MPs was bigger and more complex than those of mangrove sediment,illustrating that MPs can act as a distinct habitat in this special ecosystem.This study provides a new perspective for increasing our understanding of microplastic pollution in mangrove ecosystems.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2024A1515030201,2022A1515010197)the National Natural Science Foundation of China(41807476,42377363,42177253)Guangzhou Science and Technology Project of China(Basic and Applied Basic Research project)(202102020892).
文摘In this study,bismuth ferrite(BiFeO_(3),BFO)catalysts doped with different contents of peanut shell biochar(BC)were prepared and used in the removal of antibiotic-resistant bacteria(ARB)by peroxymonosulfate(PMS)activation from wastewater.The PMS(0.03 mM)/5%BC-BFO(0.5 g L^(−1))system removed 1.92 log ARB within 10 min of reaction at a reaction rate of 0.4401 min^(−1).Raman spectra analysis revealed that 5%BC-BFO exhibited more defects and oxygen vacancies(Ov),which provided active sites for PMS activation to generate SO_(4)^(⋅−),O_(2)^(⋅−),and^(1)O_(2),thereby promoting ARB inactivation.The oxidation of PMSO to PMSO₂suggests that high-valent iron-oxo species may also be involved in the inactivation of ARB.The PMS/5%BC-BFO system caused oxidative damage to the ARB cell membrane,increasing its permeability from 4.34%to 46.00%.Simultaneously,it triggered the activation of bacterial self-defense mechanisms and a cascade reaction,leading to the upregulation of intracellular reactive oxygen species(ROS)levels(rising from 6.34%to 62.90%),ultimately resulting in ARB inactivation.In addition,the ARB removal under PMS activation by the fourth recycled 5%BC-BFO catalyst was 62.6%of that by the fresh 5%BC-BFO.In summary,this study proposes a low-cost and easily synthesized novel catalyst for the efficient ARB removal from wastewater.
