APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
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2023
·Vol. 107
·期 18
·5813-5827
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IF 5
Wu Tong,Guo Sheng-Zhi,Zhu Hai-Zhen,Yan Lei,Liu Zhi-Pei,Li De-Feng,Jiang Cheng-Ying,Corvini Philippe François-Xavier,Shen Xi-Hui,Liu Shuang-Jiang
Abstract Sulfonamide antibiotics (SAs) are serious pollutants to ecosystems and environments. Previous studies showed that microbial degradation of SAs such as sulfamethoxazole (SMX) proceeds via a sad -encoded oxidative pathway, while the sulfonamide-resistant dihydropteroate synthase gene, sul , is responsible for SA resistance. However, the co-occurrence of sad and sul genes, as well as how the sul gene affects SMX degradation, was not explored. In this study, two SMX-degrading bacterial strains, SD-1 and SD-2, were cultivated from an SMX-degrading enrichment. Both strains were Paenarthrobacter species and were phylogenetically identical; however, they showed different SMX degradation activities. Specifically, strain SD-1 utilized SMX as the sole carbon and energy source for growth and was a highly efficient SMX degrader, while SD-2 did could not use SMX as a sole carbon or energy source and showed limited SMX degradation when an additional carbon source was supplied. Genome annotation, growth, enzymatic activity tests, and metabolite detection revealed that strains SD-1 and SD-2 shared a sad -encoded oxidative pathway for SMX degradation and a pathway of protocatechuate degradation. A new sulfonamide-resistant dihydropteroate synthase gene, sul918 , was identified in strain SD-1, but not in SD-2. Moreover, the lack of sul918 resulted in low SMX degradation activity in strain SD-2. Genome data mining revealed the co-occurrence of sad and sul genes in efficient SMX-degrading Paenarthrobacter strains. We propose that the co-occurrence of sulfonamide-resistant dihydropteroate synthase and sad genes is crucial for efficient SMX biodegradation. Key points
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Two sulfamethoxazole-degrading strains with distinct degrading activity, Paenarthrobacter sp. SD-1 and Paenarthrobacter sp. SD-2, were isolated and identified.
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Strains SD-1 and SD-2 shared a sad-encoded oxidative pathway for SMX degradation.
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A new plasmid-borne SMX resistance gene (sul918) of strain SD-1 plays a crucial role in SMX degradation efficiency.
研究领域:
微生物学
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环境科学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
ACS Omega
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2020
·
IF 2.87
Fengqing Xiong,Danni Chen,Chenglong Ma,Limei Cao,Ji Yang
Electrochemical oxidation has been considered as an efficient method to degrade pharmaceuticals and personal care products. Maintaining low power consumption while increasing the number of oxidation intermediates is deserving of exploring. Herein, Ti/SnO2–Sb/Zr0.3Ir0.7O2 was prepared by Zr doped into IrO2 and used for Sulfamethoxazole (SMX) degradation. The addition of Zr significantly increased the electrochemically active area and facilitated the catalyst to degrade SMX dramatically at a lower overpotential. The extremely outstanding lifetime of catalysts can reach 800 h during the accelerated life test, which showed excellent stability and developmental prospects. The overpotential at 10 mA·cm–2 is about 329 mV, indicating that this electrode has a high oxygen evolution reaction activity. Furthermore, the electrical efficiency per log order for the electrode is only 8.50 kW h m–3 at 4 V. Our research provides new anode electrochemical catalysts for the degradation of organic pollutants.
研究领域:
环境科学
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材料科学
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电化学工程
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Dong Hui Liang,Yongyou Hu
Little information is available regarding the kinetics, products, and pathways of simultaneous SMX degradation and Cd(II) immobilization from wastewater. In this study, a novel bacterium ( Achromobacter sp. L3) with SMX degradation and Cd(II) immobilization capabilities was isolated. The boundary conditions of SMX degradation were as follows: initial pH 6–8, temperature 25–30 °C, and SMX concentration 10–40 mg/L −1 . The boundary conditions of Cd(II) immobilization were as follows: initial pH 7–9, temperature 25–35 °C, and SMX concentration 10–30 mg/L −1 . The maximum SMX degradation and Cd(II) removal were 91.98% and 100%, respectively. The SMX degradation and Cd(II) immobilization data fitted well with the pseudo-first-order kinetic model, indicating that the two pollutants conform to the same degradation rule. Moreover, the microbial degradation , sediment adsorption, and intermediates identified in the experiments were used to explore the mechanisms of SMX and Cd(II) removal. These results indicate that microbial removal and sediment adsorption play equally important roles in Cd(II) immobilization; however, microbial degradation plays a decisive role in SMX degradation. Furthermore, the relationship between aerobic denitrification, SMX degradation, and Cd(II) immobilization was proposed. These results may provide valuable insights for treatment of wastewater polluted by antibiotics and heavy metals.
研究领域:
环境微生物学
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废水工程
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污染控制
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Shizong Wang,Lejin Xu,Jianlong Wang
Metal-free carbonaceous persulfate activator has received increasing attention recently. Graphitic carbon nitride (g-C 3 N 4 ) is one of the promising carbon materials due to excellent stability and low cost, but its activity for peroxymonosulfate (PMS) activation is low. In this study, g-C 3 N 4 was modified with oxygen atoms in the first step (O-g-C 3 N 4 ), then exfoliated via sequential thermal and ultrasound treatment to produce O-g-C 3 N 4 nanoflakes to increase its catalytic activity to activate PMS. In the presence of O-g-C 3 N 4 nanoflakes, SMX degradation rate achieved 0.079 min −1 , which was much faster than that in the presence of pristine g-C 3 N 4 (0.0083 min −1 ) and untreated O-g-C 3 N 4 (0.012 min −1 ). The surface-bound radicals and direct electron transfer between SMX and PMS contributed to the SMX degradation. Density functional theory (DFT) simulation revealed that oxygen-doping changed the charge distribution. Furthermore, O-g-C 3 N 4 nanoflakes had higher adsorption energy for PMS and SMX (0.518 kcal/mol) than pristine g-C 3 N 4 (0.304 kcal/mol), which contributed to the enhanced PMS activation and SMX degradation. Cycling experiments and comparison of characterization results before and after experiments proved that O-g-C 3 N 4 nanoflakes had superior catalytic and structural stability. This study could provide a high efficient metal-free carbonaceous activator of PMS for the degradation of antibiotics in the wastewater.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Jialong Yin,Heng Zhang,Mengfan Luo,Jia Zhao,Bingkun Huang,Pinji Chen,Zhenpeng Cai,Yue Yuan,Yang Liu,Chuanshu He,Bo Lai
The ferrous species (Fe(II))-periodate (PI) system employs efficient decontamination by generating ferryl species (Fe(IV)-oxo) under acidic pH conditions. However, the mechanisms by which the Fe(II)/PI system operates across a broad pH range remain elusive. In light of the rapid oxidation and consumption of Fe(II) at neutral pH, we developed an electro-Fe(II) system utilizing an iron plate anode to activate PI (E(Fe/C)/PI). Efficient sulfamethoxazole (SMX) degradation was achieved under the E(Fe/C)/PI system across a range of pH values. Quenching and chemical probe experiments revealed a transition from Fe(IV)-oxo to singlet oxygen ( 1 O 2 ) as the predominant reactive species from acidic to near-neutral pH, respectively. Density functional theory (DFT) calculations indicated that the differences in one-electron transfer capacity and hydrolysis pathways for various protonated Fe(IV)-oxo species underlie the variations in catalytic mechanisms. This study not only enhances the efficiency of the Fe(II)/PI system but also provides a comprehensive understanding of the activation mechanisms at different pH levels.
研究领域:
环境化学
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电化学
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催化
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水处理
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产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2021
·
IF 6.498
Shengnan Li,Xuya Zhu,Hang Yu,Xizi Wang,Xiaqing Liu,Hui Yang,Fengxiang Li,Qixing Zhou
Antibiotic wastewater presents serious challenges in water treatment . Metal-organic frameworks (MOFs) have received significant attention as promising precursors and sacrificial templates in the preparation of porous carbon-supported catalysts. Herein, we investigated the sulfamethoxazole (SMX) degradation and electrochemical performance of microbial fuel cells (MFCs) that applied as-prepared Ni-MOF-74 and Ni–N–C (Ni-MOF-74 underwent pyrolysis treatment at different temperatures) as air-cathode catalyst. Firstly, the electrocatalytic activity towards oxygen reduction reaction (ORR) of the catalyst was investigated by rotating disk electrode. The results showed that electron transfer number for Ni-MOF-74 was 2.12, while that of 800Ni–N–C was 3.44, which was close to four-electron reduction. Applying Ni-MOF-74 in MFCs, a maximum power density of 446 mW/m 2 was obtained, which was close to that of 800Ni–N–C. Besides, using Ni-MOF-74 as cathode catalyst, a chemical oxygen demand removal rate of about 84% was obtained, and the degradation rate of 10 mg/L SMX was 61%. The degradation rate decreased with increasing antibiotic concentration, but the average degradation efficiency increased stepwise. Additionally, the relative abundance of resistant gene sul1 in the reactors of the new catalytic material was about 62% lower than that of sul1 in the control (Pt/C) reactors, and the relative abundance of sul2 was about 73% lower. Moreover, cost assessments related to the catalyst performance are presented. The findings of this study demonstrated that Ni-MOF-74 could be considered as a two-electron transfer ORR catalyst, and offers a promising technique for preparation of Ni–N–C for use as four-electron transfer ORR catalysts. In comparison, Ni-MOF-74 could be a promising ORR catalyst of MFCs for antibiotic degradation.
研究领域:
环境工程
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生物化学
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催化
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水处理
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产品关联
DOI
PubMed
高影响因子
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