SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Wubin Liao,Peng Liao,Zheng Wang,Chenggang Ci,Shiwei Xie
The dephosphorylation of N-containing phosphonates is crucial for mitigating their potential ecological risks and enabling phosphorus resource recovery. Here, we first show that the electrochlorination process outperforms other advanced oxidation methods in terms of conversion efficiency and rate constants for orthophosphate production. The high efficacy of electrochlorination process is primarily attributed to the generation of hypochlorous acid (HClO) under neutral pH conditions, as substantiated by a combination of speciation analysis, quantitative assessments, and quenching experiments. Furthermore, density functional theory (DFT) calculation and LC-MS measurements show that the degradation of nitrilotris-methylenephosphonic acid (NTMP) by HClO occurs spontaneously, with a preferential cleavage of the C P bond over the C N bond, thereby facilitating the efficiency of the dephosphorylation reaction. Altogether, our findings provide key insights into the role of reactive chlorine species in the degradation of N-containing phosphonates, offering valuable evidence for the development of next-generation, more effective phosphorus recovery strategies.
研究领域:
环境科学
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化学工程
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2018
·
IF 3.974
Fei Li,Lin Di,Yuxin Liu,Qiuyun Xiao,Xiaoyu Zhang,Fuying Ma,Hongbo Yu
Although ascomycetes occupy a vaster niche in soil than the well-studied basidiomycetes , they have received limited attention in studies related to bioremediation. In this study, the degradation of carbaryl by Xylaria sp. was studied in different culture conditions and its possible metabolic pathway was elucidated. In liquid culture, 99% of the added carbaryl was eliminated when cytochrome P450 (CYP450) was active, which was similar to the degradation rate of Pleurotus ostreatus , a fungus with strong bioremediation ability. Mn 2+ is beneficial to the degradation of carbaryl. Compared to the 72.17% degradation rate in sterile soil, 59.0% carbaryl was eliminated in non-sterile soil, which suggested that Xylaria sp. BNL1 can resist microorganismal infection. Furthermore, the intracellular fractions containing laccase, CYP450, and carbaryl esterase efficiently degraded carbaryl. The presence of carbaryl metabolites suggested that Xylaria sp. BNL1 initiated its attack on carbaryl via carbaryl esterase to release α-naphthol, which was further degraded to 1,4-naphthoquinone and benzoic acid by CYP450 and laccase. Thus, our study highlights the potential of using Xylaria sp. for bioremediation.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2019
·Vol. 85
·期 12
·
IF 4.077
Xinyu Lu,Weiwei Wang,Lige Zhang,Haiyang Hu,Ping Xu,Tao Wei,Hongzhi Tang
N,N-Dimethylformamide (DMF) is one of the most common xenobiotic chemicals, and it can be easily emitted into the environment, where it causes harm to human beings. Herein, an efficient DMF-degrading strain, DM1, was isolated and identified as Methylobacterium sp. This strain can use DMF as the sole source of carbon and nitrogen. Whole-genome sequencing of strain DM1 revealed that it has a 5.66-Mbp chromosome and a 200-kbp megaplasmid. The plasmid pLVM1 specifically harbors the genes essential for the initial steps of DMF degradation, and the chromosome carries the genes facilitating subsequent methylotrophic metabolism. Through analysis of the transcriptome sequencing data, the complete mineralization pathway and redundant gene clusters of DMF degradation were elucidated. The dimethylformamidase (DMFase) gene was heterologously expressed, and DMFase was purified and characterized. Plasmid pLVM1 is catabolically crucial for DMF utilization, as evidenced by the phenotype identification of the plasmid-free strain. This study systematically elucidates the molecular mechanisms of DMF degradation by Methylobacterium.IMPORTANCE DMF is a hazardous pollutant that has been used in the chemical industry, pharmaceutical manufacturing, and agriculture. Biodegradation as a method for removing DMF has received increasing attention. Here, we identified an efficient DMF degrader, Methylobacterium sp. strain DM1, and characterized the complete DMF mineralization pathway and enzymatic properties of DMFase in this strain. This study provides insights into the molecular mechanisms and evolutionary advantage of DMF degradation facilitated by plasmid pLVM1 and redundant genes in strain DM1, suggesting the emergence of new ecotypes of Methylobacterium.
研究领域:
环境微生物学
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生物化学
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2022
·Vol. 88
·期 4
·
IF 5.005
Zhijian Ke,Qian Zhu,Siyuan Gao,Mingliang Zhang,Mingli Jiang,Yijun Ren,Yali Liu,Yidong Zhou,Jiguo Qiu,Qing Hong
Previously, a LysR family transcriptional regulator, McbG, that activates the mcbBCDEF gene cluster involved in the upstream pathway (from carbaryl to salicylate) of carbaryl degradation in Pseudomonas sp. strain XWY-1 was identified by us (Z. Ke, Y. Zhou, W. Jiang, M. Zhang, et al., Appl Environ Microbiol 87:e02970-20, 2021, https://doi.org/10.1128/AEM.02970-20). In this study, we identified McbH and McbN, which activate the mcbIJKLM cluster (responsible for the midstream pathway, from salicylate to gentisate) and the mcbOPQ cluster (responsible for the downstream pathway, from gentisate to pyruvate and fumarate), respectively. They both belong to the LysR family of transcriptional regulators. Gene disruption and complementation study reveal that McbH is essential for transcription of the mcbIJKLM cluster in response to salicylate and McbN is indispensable for the transcription of the mcbOPQ cluster in response to gentisate. The results of electrophoretic mobility shift assay (EMSA) and DNase I footprinting showed that McbH binds to the 52-bp motif in the mcbIJKLM promoter area and McbN binds to the 58-bp motif in the mcbOPQ promoter area. The key sequence of McbH binding to the mcbIJKLM promoter is a 13-bp motif that conforms to the typical characteristics of the LysR family. However, the 12-bp motif that is different from the typical characteristics of the LysR family regulator binding site sequence is identified as the key sequence for McbN to bind to the mcbOPQ promoter. This study revealed the regulatory mechanisms for the midstream and downstream pathways of carbaryl degradation in strain XWY-1 and further our knowledge of (and the size of) the LysR transcription regulator family.IMPORTANCE The enzyme-encoding genes involved in the complete degradation pathway of carbaryl in Pseudomonas sp. strain XWY-1 include mcbABCDEF, mcbIJKLM, and mcbOPQ. Previous studies demonstrated that the mcbA gene, responsible for hydrolysis of carbaryl to 1-naphthol, is constitutively expressed and that the transcription of mcbBCDEF was regulated by McbG. However, the transcription regulation mechanisms of mcbIJKLM and mcbOPQ have not been investigated yet. In this study, we identified two LysR-type transcriptional regulators, McbH and McbN, which activate the mcbIJKLM cluster (responsible for the degradation of salicylate to gentisate) and the mcbOPQ cluster (responsible for the degradation of gentisate to pyruvate and fumarate), respectively. The 13-bp motif is critical for McbH to bind to the promoter of mcbIJKLM, and 12-bp motif different from the typical characteristics of the LysR-type transcriptional regulator (LTTR) binding sequence affects the binding of McbN to the promoter. These findings help to expand the understanding of the regulatory mechanism of microbial degradation of carbaryl.
研究领域:
微生物学
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分子生物学
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环境科学
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Chengyi Wang,Siyue Xue,Yubo Xu,Ran Li,Yangbo Qiu,Chao Wang,Long-Fei Ren,Jiahui Shao
Phosphonate is becoming a global interest and concern owing to its environment risk and potential value. Degradation of phosphonate into phosphate followed by the recovery is regarded as a promising strategy to control phosphonate pollution, relieve phosphorus crisis, and promote phosphorus cycle. Given these objectives, an anion-membrane-coated-electrode (A-MCE) doped with Fe-Co based carbon catalyst and cation-membrane-coated-electrode (C-MCE) doped with carbon-based catalyst were prepared as catalytic electrodes, and a novel electrocatalytic capacitive deionization (E-CDI) was developed. During charging process, phosphonate was enriched around A-MCE surface based on electrostatic attraction, ligand exchange, and hydrogen bond. Meanwhile, Fe 2+ and Co 2+ were self-oxidized into Fe 3+ and Co 3+ , forming a complex with enriched phosphonate and enabling an intramolecular electron transfer process for phosphonate degradation. Additionally, benefiting from the stable dissolved oxygen and high oxygen reduction reaction activity of C-MCE, hydrogen peroxide accumulated in E-CDI (158 μM) and thus hydroxyl radicals (·OH) were generated by activation. E-CDI provided an ideal platform for the effective reaction between ·OH and phosphonate, avoiding the loss of ·OH and triggering selective degradation of most phosphonate. After charging for 70 min, approximately 89.9% of phosphonate was degraded into phosphate, and phosphate was subsequently adsorbed by A-MCE. Results also showed that phosphonate degradation was highly dependent on solution pH and voltage, and was insignificantly affected by electrolyte concentration. Compared to traditional advanced oxidation processes, E-CDI exhibited a higher degradation efficiency, lower cost, and less sensitive to co-existed ions in treating simulated wastewaters. Self-enhanced and selective degradation of phosphonate, and in-situ phosphate adsorption were simultaneously achieved for the first time by a E-CDI system, showing high promise in treating organic-containing saline wastewaters.
研究领域:
环境科学
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电化学工程
·
废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Huoyong Jiang,Xuexiu Yu,Jingjing Guo,Guangdong Shang,Yijun Dai
The amides 4-trifluoromethylnicotinamide, acrylamide, and benzamide are widely used in agriculture and industry, posing hazards to the environment and animals. Immobilized bacteria are preferred in wastewater treatment, but degradation of these amides by immobilized engineered bacteria has not been explored. Here, engineered Pseudomonas putida KT2440 pLSJ15-amiA was constructed by introducing a new amidase gene expression vector into environmentally safe P. putida KT2440. P. putida KT2440 pLSJ15-amiA had high amidase activity, even at 80 °C. P. putida KT2440 pLSJ15-amiA immobilized with calcium alginate exhibited a greater environmental tolerance than free cells. The amides were rapidly degraded by the immobilized cells, but the activity was inhibited by high concentrations of substrates. The substrate inhibition model revealed that the optimum initial concentrations of 4-trifluoromethylnicotinamide, acrylamide, and benzamide for degradation by immobilized cells were 197.65, 350.76, and 249.40 μmol/L, respectively. This study develops a novel and excellent immobilized biocatalyst for remediation of wastewater containing hazardous amides.
研究领域:
微生物学
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环境科学
·
基因工程
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Liangbo Xie,Xueyue Mi,Yigang Liu,Yi Li,Yan Sun,Sihui Zhan,Wenping Hu
Polyacrylamide (PAM) in environmental water has become a major problem in water pollution management due to its high molecular mass, corrosion resistance, high viscosity, and nonabsorption by soil. The composite of Fe-doped Ce0.75Zr0.25O2 solid solution (Fe-Ce0.75Zr0.25O2) loaded on carbon felt (CF) was fabricated by a hydrothermal synthesis method, which was used as the cathode in a heterogeneous electro-Fenton system for the degradation of PAM. It showed that the degradation efficiency of PAM by the Fe-Ce0.75Zr0.25O2/CF cathode was 86% after 120 min and the molecular mass of PAM decreased by more than 90% after 300 min. Total organic carbon removal reached 78.86% in the presence of Fe-Ce0.75Zr0.25O2/CF, while the value was only 38.01% in the absence of Fe-Ce0.75Zr0.25O2. Further studies showed that the breaking of the chain begins with the amide bond, and then, the carbon chain was cracked into a short alkyl chain. As degradation progressed, both the complex viscosity and elasticity modulus of PAM solutions decreased nearly 50% at 300 min. It indicated that •OH were the most significant active species for the degradation of PAM. This novel Fe-Ce0.75Zr0.25O2/CF composite is an efficient and promising electrode for the removal of PAM in wastewater.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yatao Yang,Xiaoxiao Ding,Zequan Zeng,Weihong Jiao,Yifan Li,Yaqin Hou,Zhanggen Huang
TiO 2 -based catalysts are extensively employed in flue gas pollution control processes, including volatile organic compounds (VOCs) oxidation and selective catalytic reduction (SCR). Nonetheless, there persists challenges related to the lack of a clear mechanistic understanding and high N 2 selectivity for the selective oxidation of nitrogen-containing volatile organic compounds (NVOCs). Herein, titania nanotube-supporting transition metals oxides catalysts were prepared to degrade N, N-dimethylformamide (DMF). The results manifested that the interaction between metal and support (M−O−Ti) could enhance oxygen vacancy (O v ), hence promote the DMF decomposition. CuTi catalyst with high O v content exhibited the highest activity and N 2 selectivity for DMF decomposition. In situ diffuse reflectance infrared fourier transform spectroscopy (DRIFTs) and density functional theory (DFT) calculation also proved that CuTi catalyst facilitated the degradation of DMF into dimethylamine (DMA). Moreover, the MnTi catalyst with higher content of lattice oxygen was advantageous in facilitating the complete degradation of DMF into CO 2 , which enhanced CO 2 selectivity. This study could provide theoretical guidance for the practical industrial degradation of NVOCs using TiO 2 -based catalysts.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Environmental Science & Engineering
·
2020
·Vol. 14
·期 6
·1-12
·
IF 4.053
Li Wenyue,Chen Min,Zhong Zhaoxiang,Zhou Ming,Xing Weihong
High-concentration industrial wastewater containing N,N -dimethylacetamide (DMAc) from polymeric membrane manufacturer was degraded in Cu 2 O NPs/H 2 O 2 Fenton process. In the membrane-assisted Fenton process DMAc removal rate was up to 98% with 120 min which was increased by 23% over the batch reactor. It was found that ·OH quench time was extended by 20 min and the maximum ·OH productivity was notably88.7% higher at 40 min. The degradation reaction rate constant was enhanced by 2.2 times with membrane dispersion ( k = 0.0349 min −1 ). DMAc initial concentration ( C 0 ) and H 2 O 2 flux ( J p ) had major influence on mass transfer and kinetics, meanwhile, membrane pore size ( r p ) and length ( L m ) also affected the reaction rate. The intensified radical yield, fast mass transfer and nanoparticles high activity all contributed to improve pollutant degradation efficiency. Time-resolved DMAc degradation pathway was analyzed as hydroxylation, demethylation and oxidation leading to the final products of CO 2 , H 2 O and NO 3 − (rather than NH 3 from biodegradation). Continuous process was operated in the dual-membrane configuration with in situ reaction and separation. After five cycling tests, DMAc removal was all above 95% for the initial [DMAc] 0 = 14,000 mg/L in wastewater and stability of the catalyst and the membrane maintained well.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）