Water
·
2023
·Vol. 15
·期 16
·2977
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IF 3.4
Shaoqing Zhang,Hang Zhang,Yucheng Feng,Naga Raju Maddela,Shugeng Li,Liqiu Zhang
This study aimed at investigating the potential impacts of perfluorooctanoic acid (PFOA) exposure on the partial denitrification (PD) system. Our results indicated that nitrite accumulation rates were significantly decreased to 67.94 ± 1.25%–69.52 ± 3.13% after long-term PFOA exposure (0.5–20 mg/L), while the nitrate transformation ratio was slightly impacted. The PFOA removal efficiency gradually decreased from 67.42 ± 3.39% to 6.56 ± 5.25% with an increasing PFOA dosage, indicating that the main PFOA removal pathway was biosorption. The average EPS contents increased by two folds, which suggested that exposure to PFOA significantly stimulated EPS secretion. Excitation emission matrix analysis revealed that PFOA exposure promoted the secretion of tryptophan protein-like, humic acid-like, and aromatic protein II-like substances, which may act as a protective barrier against PFOA toxicity. Moreover, significant changes in characteristic peaks after PFOA exposure were shown as indicated by Fourier transform infrared spectroscopy. High-throughput sequencing suggested that PFOA significantly decreased bacterial richness and increased evenness, indicating that toxicity effects of PFOA were more pronounced for abundant species (e.g.,Thauera) than rare species.Thauerawas the most dominant genus responsible for nitrite accumulation, whose abundance significantly decreased from 35.99 ± 2.67% to 18.60 ± 2.18% after PFOA exposure. In comparison, the abundances of common denitrifiers, such asDenitratisoma,Bdellovibrio, andOLB8, significantly increased, suggesting that these genera were potential PFOA-resistant bacteria. This study presents new insights into the effect of PFOA on a PD system.Keywords:partial denitrification;nitrite accumulation;perfluorooctanoic acid;extracellular polymers;microbial community
研究领域:
环境工程
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微生物学
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污水处理
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DOI
高影响因子
BIOORGANIC CHEMISTRY
·
2025
·
IF 4.7
Wenjian Dong,Yifan Wang,Chunhua Ni,Xuefeng Yan,Liangmin Yu,Xia Li,Na Li,Jian Yang,Junchao Yin
Marine antifouling materials based on fluorescence characteristics are the development trend for environmentally friendly marine antifouling coatings. Existing fluorescent antifouling materials face limitations such as limited functions and unclear mechanisms. A novel fluoranthene derivative was synthesized by Friedel–Crafts alkylation reaction, after which zinc acrylate resin containing the derivative was prepared. The results of the performance evaluation revealed that the inhibitory effect of the resin on algae growth was 28.4 %, and the antiadhesion effect increased by 72.7 %, which indicated that the resin had chemical repellent properties. Compared with that under the incubator light, the antiadhesion performance under sunlight increased by 52.4 %. The concentrations of photosynthetic pigments in the algae increased by 41.2 % (carotenoids), whereas the EPS decreased by 42.6 % (RPS) and 13.1 % (CPS). These results suggested that the fluorescence effect promoted the photosynthesis of algae and reduced the secretion of EPS. The actual sea antifouling test results confirmed that the resin has excellent antifouling effects because of its combination of fluorescence, chemical repellency and self-polishing properties. This study laid the foundation for the development of a multifunctional and environmentally friendly marine antifouling material belt.
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PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Shuyue Wang,Dan Hu,Yang Liu,Huixin Xiong
Antibiotics pollutants are arousing seriously environmental issues, so the highly efficient photo-Fenton catalysts have been developed in their treatments. In this work, according to the results of XRD, Raman, FTIR, and XPS, ferrihydrite/polyaniline (Fh/PANI) catalyst could be successfully prepared in waste iron-bacterial cultures (shorted as Fe(III)/EPS-solutions) with PANI conductor ((C 6 H 7 N) n , 200–300 nm). The Fh/PANI was an optimal photo-Fenton catalyst with good physical properties for tetracycline hydrochloride (TCH, C 22 H 25 ClN 2 O 8 ) degradation. In photo-Fenton systems with 30 mmol/L H 2 O 2 , 40 mg/L TCH, 0.2 g/L catalyst, and pH 4.0 under the visible light irradiation, degradation efficiency was 94% for Fh/PANI (82% for Fh). Kinetics data of TCH degradation well followed to pseudo-first-order model ( R 2 =0.974 for Fh/PANI, and R 2 =0.929 for Fh). The Fh/PANI catalyst had a good stability for TCH degradation, and the efficiencies ranged in 94%−77% within its five runs. The TCH could be efficiently mineralized into H 2 O and CO 2 inorganic molecules, and the producing ∙O 2 − was the key action group. These results indicate Fh/PANI photo-Fenton catalyst will have a potential application in treating antibiotic polluted waters. It also can provide a good approach of preparing Fe-(oxyhydr)oxide/conductor composites in waste iron-bacterial cultures.
研究领域:
环境科学
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生物化学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Dongchao Qiu,Chuchu Zheng,Youyun Zeng,Lixia Wu,Chen Huang,Ying Ran,Yiqin Ding,Jiayi Shi,Xiaojun Cai,Yihuai Pan
It is an effective method of eradicating biofilm infection and promoting wound healing by exopolysaccharides (EPS) degradation and penetration of antimicrobial agents into biofilms. In this study, a synergistic antimicrobial nanoplatform (Pec@PLL-MoS 2 ) based on programmed enzymolysis and photothermal therapy was developed. Pectinase (Pec) was modified onto the surface of molybdenum disulfide nanosheets (MoS 2 NSs) by ε-poly-L-lysine (PLL) linkage via electrostatic adsorption. With the 808-nm laser irradiation, the activity of Pec was regulated by the photothermal effect produced by the MoS 2 NSs. Pec efficiently degraded the EPS and destroyed the structural integrity of the biofilms, thus promoting the penetration of Pec@PLL-MoS 2 into the biofilms. With the penetration of Pec@PLL-MoS 2 , the local hyperthermia produced by the photothermy of the MoS 2 NSs further killed the bacteria inside the biofilms, eventually eradicating biofilm infections. In vitro experiments indicated that 81.1 % of Staphylococcus aureus ( S. aureus ) biofilms and 89.9 % of Escherichia coli ( E. coli ) biofilms were eradicated within 5 min. The survival rates of the bacteria in the biofilms of S. aureus and E. coli were reduced to 5.1 % and 0.1 %, respectively. In vivo, biofilm infections in wounds were completely eradicated by Pec@PLL-MoS 2 under irradiation, thereby reducing inflammation and promoting wound healing. This study demonstrated that Pec@PLL-MoS 2 based on programmed enzymolysis and photothermia is a new synergistic treatment strategy for biofilm infections.
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高影响因子
DESALINATION
·
2023
·
IF 9.9
Jing Song,Yihan Li,Shihan Wang,Rui Han,Yu Ba,Ying Liu,Shengqiang Fan
Membrane Electro-Bioreactor (MEBR), with dual function of electrochemical in-situ membrane fouling mitigation and pollutants removal by chlorine evolution reaction (CIER), has emerged as a promising technology of treating mariculture wastewater. However, the fouling control mechanism regarding extracellular polymeric substance (EPS) variations and related microbial community is still unclear. In this study, MEBR was developed with conducting anode-membrane modified by CNTs-TiO 2 -PEDOT for fouling resistant and ammonia/nitrite removal. The CIER electroactivity was enhanced that onset potential negatively shifted from 1.12 to 0.98 V vs. SCE (saturated calomel electrode). Ammonia removal rate (71.49 mgN/(L·day)) was 176.8 % higher and nitrite was significantly reduced in MEBR than MBR at HRT of 45 min. Membrane fouling was mitigated in MEBR that operation duration was extended by 40 % compared with MBR. The EPS of cake layer on the membrane surface rather than the biofilters was found the main fouling contributor. The significant reduction in LB-EPSp (65.4 %) in MEBR (33.8 % in MBR) was the dominant factor contributing to membrane fouling alleviation, which highly depended on the relative abundance of Hyphomonas and Hirschia . This study will be beneficial for fouling control in seawater treatment.
研究领域:
环境工程
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水处理
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生物技术
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电化学
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高影响因子
WATER RESEARCH
·
2019
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IF 7.913
Yang Lv,Keke Xiao,Jiakuan Yang,Yuwei Zhu,Kangyue Pei,Wenbo Yu,Shuangyi Tao,Hui Wang,Sha Liang,Huijie Hou,Bingchuan Liu,Jingping Hu
Pre-oxidation is effective in enhancing sludge dewaterability. Different types and doses of oxidants are used to improve sludge dewaterability in pre-oxidation. Rapid evaluation of the sludge dewaterability is vital for optimizing the type and dose of oxidants in pre-oxidation. It normally takes more time to evaluate sludge dewaterability by measuring typical indicators such as specific resistance to filtration (SRF), content of bound water, and composition of EPS. This study presented a rapid parameter, oxidation-reduction potential (ORP), to correlate it with the dewaterability of pre-oxidized sludge samples. An index of ΔORP (ΔORP = ORP t=0.5 min –ORP t=0 min ) showed positive correlations with SRF ( r = 0.89, p < 0.05), content of total organic carbon in soluble and loosely-bound EPS ( r = 0.86 and 0.84, p < 0.05), zeta potential ( r = 0.86, p < 0.05), and content of Fe(III) in the sludge cake ( r = 0.92, p < 0.01). However, the ΔORP index showed negative correlations with tryptophan-like proteins, tyrosine-like proteins, microbial byproduct-like materials in tightly-bound EPS ( r = −0.85, −0.90 and −0.90, p < 0.05), and sludge particle sizes ( p < 0.01). A multiple linear regression model was developed to further reflect the linear correlation between the ΔORP values and the key factors reflecting sludge dewaterability. An optimal dose of oxone (0.4 mmol/g VS) for sludge pre-oxidation with the ΔORP value of 387 mV combined with Fe(III) coagulation conditioning system were verified by the results of dewatering experiments using a laboratory-scale diaphragm filter press. This study demonstrated the feasibility of using ΔORP as a potential rapid evaluation tool for sludge dewaterability.
研究领域:
环境工程
·
水处理
·
污水处理
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Ming Wu,Zhen-Hu Yang,Tong-Bao Jiang,Wen-Wen Zhang,Zhi-Wei Wang,Qing-Xi Hou
Conductive materials have been demonstrated to enhance sludge methanogenesis , but few researches have concentrated on the interaction among conductive materials, microorganisms and their immediate living environment. In this study, Fenton iron mud with a high abundance of Fe(III) was recycled and applied in anaerobic reactors to promote anaerobic digestion (AD) process. The results show that the primary content of extracellular polymeric substances (EPS) such as polysaccharides and proteins increased significantly, possibly promoting microbial aggregation. Furthermore, with the increment of redox mediators including humic substances in EPS and Fe(III) introduced by Fenton iron mud, the direct interspecies electron transfer (DIET) between methanogens and interacting bacteria could be accelerated, which enhanced the rate of methanogenesis in anaerobic digestion (35.21 ± 4.53% increase compared to the control). The further analysis of the anaerobic microbial community confirmed the fact that Fenton iron mud enriched functional microorganisms, such as the abundance of CO 2 -reducing (e.g. Chloroflexi) and Fe(III)-reducing bacteria (e.g., Tepidimicrobium ), thereby expediting the electron transfer reaction in the AD process via microbial DIET and dissimilatory iron reduction (DIR). This work will make it possible for using the recycled hazardous material – Fenton iron mud to improve the performance of anaerobic granular sludge during methanogenesis.
研究领域:
环境工程
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微生物学
·
废物管理
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2024
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IF 10.7
Fang Ting Gu,Jun Hui Li,Zi Chen Zhao,Yan Yu Zhu,Lin Xi Huang,Jian Yong Wu
This study was to assess the digestion and colonic fermentation of two bioactive polysaccharides, EPS-LM and LBPS, and the subsequent influences on human gut microbiota through simulated gastrointestinal systems. EPS-LM, an exopolysaccharide isolated from mycelial culture of a medicinal fungus Cordyceps sinensis Cs-HK1, was characterized as a heteropolysaccharide consisting of Man(108):Gal(52.7):Glc(29.2) (molar ratio) with an average molecular weight (MW) 5.513 × 10 6 . LBPS was isolated from a well-known medicinal plant ( Lycium barbarum L.) which was also characterized as a heteropolysaccharide (1.236 × 10 5 MW). Both polysaccharides were highly resistant to saliva, gastric and small-intestine digestion with negligible MW reduction and release of reducing sugars but were quickly degraded to lower MW during in vitro human fecal fermentation. They were consumed as a carbon source by the gut bacteria to produce short-chain fatty acids (SCFAs). In comparison, the carbohydrate content of EPS-LM was more completely consumed than LBPS and there were also notable differences in consumption of specific monosaccharides and production of specific SCFAs, propionic and butyric acid, and relative abundance of gut bacterial populations between EPS-LM and LBPS group. The results suggest that metabolic outcomes and modulating effects of EPS-LM and LBPS on the gut microbiota are highly dependent on their molecular composition.
研究领域:
微生物学
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营养科学
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胃肠病学
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Weiping Chen,Bingzheng Wang,Yaqing Wang,Ji Li
Antibiotics are widely used drugs in the world and pose serious threats to ecosystems and human health. Although it has been reported that ammonia oxidizing bacteria (AOB) can cometabolize antibiotics, little has been reported on how AOB would respond to the exposure of antibiotics on extracellular and enzymatic levels, as well as the impact of antibiotics on the bioactivity of AOB. Therefore, in this study, a typical antibiotic, sulfadiazine (SDZ), was selected, and a series short-term batch tests using enriched AOB sludge were conducted to investigate the intracellular and extracellular responses of AOB along the cometabolic degradation process of SDZ. The results showed the cometabolic degradation of AOB made the main contribution to SDZ removal. When the enriched AOB sludge was exposed to SDZ, ammonium oxidation rate, ammonia monooxygenase activity, adenosine triphosphate concentration and dehydrogenases activity were negatively affected. The amoA gene abundance increased 1.5 folds within 24 h, which may enhance the uptake and utilization of substrates and maintain stable metabolic activity. In the tests with and without ammonium, the concentration of total EPS increased from 264.9 to 231.1 mg/gVSS to 607.7 and 538.2 mg/gVSS, respectively, under the exposure to SDZ, which was mainly contributed by the increase of proteins in tightly bound extracellular polymeric substances (EPS) and polysacharides in tightly bound EPS and soluble microbial products. The proportion of tryptophan-like protein and humic acid-like organics in EPS also increased. Moreover, SDZ stress stimulated the secretion of three quorum sensing signal molecules, C4-HSL (from 140.3 to 164.9 ng/L), 3OC6-HSL (from 17.8 to 42.4 ng/L) and C8-HSL (from 35.8 to 95.9 ng/L) in the enriched AOB sludge. Among them, C8-HSL may be a key signal molecule that promoted the secretion of EPS. The findings of this study could shed more light on the cometabolic degradation of antibiotics by AOB.
研究领域:
环境微生物学
·
生物降解与生物转化
·
抗生素污染
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PubMed
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Yinghui Zhang,Kun Dong,Meng Zhang,Xiaofei Wang,Xuehong Zhang,Dunqiu Wang,Ruize Sun,Haixiang Li,Wenjie Zhang
Hydrogen-based membrane biofilm reactors using hollow-fiber membrane modules as their functional cores can play an important role in treating oxidizing pollutants. However, most studies have focused on pollutant removal, and few have investigated how membrane material properties affect reactor's operation. Here, we selected polyvinyl chloride (PVC) and polyvinylidene fluoride (PVDF) hollow fiber membrane materials with large differences in membrane surface properties to assemble the reactor, and investigated how the membrane properties affected nitrate removal and EPS secretion in MBfRs. The results showed that the membrane surface zeta potential and membrane contact angle had a certain positive impact on the NO 3 − -N removal rate and total EPS secretion in the MBfRs. When the contact angle (74.51–85.51°) and zeta potential (−12.5–4.5) increased, the biofilm on the membrane surface secreted more binding proteins (90.81–113.54 mg/gVSS), facilitating reactor biofilm growth, pollutant removal, and impact loads. Moreover, the properties of the experimentally selected PVC membrane material are more suitable for MBfR operation and are in line with the fundamental need for energy saving and emission reduction in modern society. This study provides a theoretical basis for the selection of membrane materials to enhance denitrification in H 2 -MBfRs, and an engineering foundation for reactors applications.
研究领域:
环境科学
·
微生物学
·
污水处理
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DOI
高影响因子
ACS ES&T Water
·
2022
·
IF 0
Xiaomei Liu,Yu Li,Jingchun Tang,Dan Wang,Saisai Guo,Qinglong Liu,John P. Giesy
The prevalence of antibiotic resistance genes (ARGs) among bacteria has become a global environmental issue. There is a lack of research on whether nano/microplastics could affect ARG transfer between bacteria. In this study, 20, 100 nm, 1 μm, and 1 mm polystyrene (PS) plastic particles were investigated to determine if nano/microplastics could affect the ARG transfer. Nanoplastics and 1 μm microplastics significantly enhanced the transfer efficiency, whereas 1 mm microplastics had no significant effect. Exposure to 0.1 mg/L 20 nm nanoplastics resulted in the highest transfer frequency, which was 8.9-fold greater than that of the control. Exposure to nanoplastics increased the expressions of genes related to outer membrane porin proteins and the key genes of conjugative transfer. Exposure to 1 μm microplastics had no significant effect on the genes related to transfer. After exposure to 1 μm microplastics, the amounts of extracellular polymeric substances (EPS) were increased, which affected the transfer efficiency. The addition of nanoplastics also could stimulate the production of EPS, and the increase of EPS content in the nanoplastic treatment group was also an important factor that affected the transfer frequency. This work provides important insights into the evaluation of the environmental and health risks of ARGs caused by microplastics.
研究领域:
环境科学
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微生物学
·
分子生物学
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ACS ES&T Water
·
2023
·
IF 5.3
Xiaocai Cui,Tian Ren,Qingqing Ren,Beibei Wu,Yun Zhou,Siqing Xia,Bruce E. Rittmann
Extracellular polymeric substances (EPS) affect the formation, properties, and function of biofilms. Understanding the roles of EPS in biofilm-related processes depends on reliable extraction and evaluation methods. However, differentiating true EPS from intracellular organic polymers released by cell lysis has proven to be difficult during EPS extraction. In this study, thermal and cation exchange resin (CER) treatments were used to extract biofilm EPS. SYTOX Green (SG) dye was used to stain nucleic acid (NA), and the enhanced fluorescence signal (FS) from the NA-SG complex was sensitively recorded by flow cytometry (FC). Results showed that thermal extraction could achieve effective EPS release, but a higher temperature and longer time caused a significant cell activity decline, protein denaturation, and cell lysis. In contrast, CER extraction had no effects on cell activity and organics denaturation, and it only caused minor cell lysis at a high CER dose. Combining all the results indicates that CER extraction using 70 g-CER/g-VSS for 2 h provided reliable and efficient extraction of biofilm EPS: high EPS extraction efficiency with minimal EPS denaturation, cell lysis, and loss of cell activity. FC combined with SG staining should be applicable for evaluating the effectiveness of EPS extraction from any microbial aggregates.
研究领域:
微生物学
·
环境工程
·
分析化学
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高影响因子
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