ENVIRONMENTAL RESEARCH
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2024
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IF 7.7
Peiwen Li,Qiansheng Li,Hong Lu,Ze Fu,Jiti Zhou,Chenghao Sun,Xuehai Wang
Some nano-biochars (nano-BCs) as electron mediators could enter into cells to directly promote intracellular electron transfer and cell activities. However, little information was available on the effect of nano-BCs on SMX degradation. In this study, nano-BCs were prepared using sludge-derived humic acid (SHA) and their effects on SMX degradation by Shewanella oneidensis MR-1 were investigated. Results showed that nano-BCs (Carbon dots, CDs, <10 nm) synthesized using SHA performed a better accelerating effect than that of the nano-BCs with a larger size (10–100 nm), which could be attributed to the better electron transfer abilities of CDs. The degradation rate of 10 mg/L SMX in the presence of 100 mg/L CDs was significantly increased by 84.6% compared to that without CDs. Further analysis showed that CDs could not only be combined with extracellular Fe(III) to accelerate its reduction, but also participate in the reduction of 4-aminobenzenesulphonic acid as an intermediate metabolite of SMX via coupling with extracellular Fe(III) reduction. Meanwhile, CDs could enter cells to directly participate in intracellular electron transfer, resulting in 32.2% and 25.2% increases of electron transfer system activity and ATP level, respectively. Moreover, the activities of SMX-degrading enzymes located in periplasm and cytoplasm were increased by around 2.2-fold in the presence of CDs. These results provide an insight into the accelerating effect of nano-BCs with the size of <10 nm on SMX degradation and an approach for SHA utilization.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Lisong Xia,Lei Cheng,Wenni Xi,Xiliang Zhang,Xianyang Shi
The environmental fate and risks of mononitrophenols (mono-NPs), the simplest nitrophenols (NPs) often found in aquatic environments, are profoundly influenced by anaerobic bioreduction and co-existing electron shuttles (ESs), but little is known about the underlying mechanisms. Here, we elucidate the pathways of anaerobic mono-NPs bioreduction by Shewanella oneidensis MR-1 and assess the effect of model ESs on these processes. We found that all three mono-NPs isomers could be readily reduced to their corresponding aminophenols by S. oneidensis MR-1 under anaerobic conditions. CymA, a core component of the Mtr respiratory pathway, performs a dynamic role in these bioreduction, which is highly dependent on the bioreduction kinetics. The exogenous addition of quinones was found to accelerate the mono-NPs bioreduction through interactions with key outer-membrane proteins (e.g., OmcA and MtrC), and all these processes matched well to linear free energy relationships (LFERs). Surprisingly, adding riboflavin did not influence the bioreduction of all three mono-NPs isomers, which may be due to the contribution of OmcA and MtrC to these bioreduction processes and their downregulated expression. This study enhances our understanding of the environmental fate of mono-NPs and their bioconversion processes, providing valuable insights for the bioremediation of nitrophenol-contaminated sites.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2022
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IF 7.336
Peng Zhang,Chenhui Yang,Zeng Li,Jia Liu,Xiang Xiao,Da Li,Chong Chen,Miao Yu,Yujie Feng
The high performance of microbial extracellular electron transfer (EET) is essential for bioremediation and bioenergy generation. Carbon dots (CDs) modified electroactive microorganisms showed an increased electron transfer efficiency. However, the influence of CDs’ concentration the EET has not been illustrated before. Herein, we reported that the addition of CDs increased the current generation by accelerating the EET process. The maximum current output of microbial electrochemical cells with the addition of CDs was increased by more than 5 times compared to pure Shewanella oneidensis MR-1. With CDs addition, the increase of biofilm immobilization and flavins secretion improved the direct and mediated EET process. Electrochemical analyses clarified that the combination of cytochrome c with CDs resulted in a faster electron transfer rate. The overload of CDs would restrict their promotion effect on EET, which may be due to their biotoxicity to bacteria. This work offered the insight of CDs’ concentration on the efficiency of EET, not only promoting the related applications of EET but also inspiring the regulation of microorganism function via nanomaterial.
研究领域:
微生物学
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环境科学
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纳米生物学
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DOI
高影响因子
Micro & Nano Letters
·
2020
·Vol. 15
·期 14
·1007-1011
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IF 0.975
Xiaojie Song,Fan Yang,Xiufang Wang,Kehua Zhang
Biogenetic nanocomposites research provides valuable methods for the green synthesis of nanomaterials. As a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1 is used to reduce Ag + to Ag nanoparticles (Ag NPs) (diameter about 10 nm) under anaerobic conditions, resulting in the in-situ formation of Ag NPs immobilised on TiO 2 nanotubes (TNTs) (Ag/TNTs nanocomposites). The loading amount of Ag nanocrystals on the TNT surface can be controlled easily through adjusting the AgNO 3 concentration and further influence visible-light absorption efficiency of Ag/TNTs nanocomposites by decreasing the Ag loading amount. Ag/TNTs nanocomposites show superior photocatalytic efficiency under simulated sunlight than single TiO 2 nanomaterials. Moreover, the photocatalytic capacity of Ag/TNTs nanocomposites synergistic by S. oneidensis MR-1 is further enhanced and the degradation ratio of methylene blue reaches 92.3% within 30 min which attributed to a synergistic effect.
研究领域:
环境科学
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微生物学
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材料科学
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DOI
高影响因子
INTERNATIONAL BIODETERIORATION & BIODEGRADATION
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2024
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IF 4.1
Liwen Zhang,Luyao Xi,Shuyu He,Huizi Wen,Shanyi Tan,Shaohua Chen
Bioremediation has garnered considerable interest due to its advantages of economy and no secondary pollution. However, the direct electron transfer rate between microorganisms and Cr(VI) is low. The bioreduction of Cr(VI) by Shewanella oneidensis MR-1 ( S. oneidensis ) in the presence of formylmethylflavin (FMF) was conducted to understand how FMF mediated the extracellular electron transfer process to improve Cr(VI) removal. In this study, FMF was firstly synthesized by modifing RF to increase its solubility and redox activity. The findings indicate that S. oneidensis /FMF exhibited better Cr(VI) removal performance compared to that of S. oneidensis . Under optimum conditions, 40 mg/L Cr(VI) could be completely removed by S. oneidensis /FMF within 120 h, while only 48.6% of Cr(VI) was removed by S. oneidensis , and the first order rate constant (k) for the Cr(VI) elimination by S. oneidensis /FMF (0.033 h −1 ) was about 4.1-fold greater than that of S. oneidensis (0.008 h −1 ). Moreover, the removal of Cr(VI) by S. oneidensis /FMF were dominated by reduction, and supplemented by adsorption and complexation. FMF enhance the extracellular electron transfer rate (EETR) was confirmed by electrochemical cyclic voltammetry (CV) and linear scanning voltammetry (LSV) experiments. This study emphasizes the potential important role of FMF in environmental bioremediation.
研究领域:
微生物学
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环境科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2019
·Vol. 26
·期 12
·12237-12246
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IF 2.914
Yang Mi,Shi Xianyang
Biosynthesized nanocomposites are attracting growing interests because they are environmentally friendly. Ag 2 S nanoparticles (Ag 2 S NPs) are deposited in situ on the surfaces of TiO 2 nanotubes (TNTs) via Shewanella oneidensis MR-1 to form Ag 2 S/TNT nanocomposites. The prepared Ag 2 S/TNTs nanocomposites are characterized using high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and energy-dispersive X-ray spectroscopy. The results show that Ag 2 S NPs smaller than 8 nm are successfully synthesized and fabricated on the TNT surfaces with relatively uniform distribution. The catalytic performance of the Ag 2 S/TNT nanocomposites is evaluated for catalytic reduction in the presence of NaBH 4 and the photocatalytic degradation of 4-nitrophenol (4-NP) under visible light. The Ag 2 S/TNT nanocomposites show excellent catalytic activity and good stability in the 4-NP reduction process. The 4-NP degradation ratio reaches 98.3% in 50 min, and 87% conversion was achieved after eight cycles. The Ag 2 S/TNT nanocomposites also exhibit excellent photocatalytic activity for 4-NP at a rate of 0.69 h −1 , and the complete degradation of 4-NP was observed within 5 h. Therefore, this study offers an environmentally friendly approach to synthesize nanocomposites for practical applications.
研究领域:
环境科学
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纳米生物学
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催化化学
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DOI
PubMed
高影响因子
BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS
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2013
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IF 3.848
Jie Yuan,Yiwen Chen,Guangqi Zhou,Haijiang Chen,Haichun Gao
Background Bacteria adopt a variety of lifestyles in their natural habitats and can alternate among different lifestyles in response to environmental changes. At high cell densities, bacteria can form extracellular matrix encased cell population on submerged tangible surfaces (biofilms), or at the air–liquid interface (pellicles). Compared to biofilm, pellicle lifestyle allows for better oxygen access, but is metabolically more costly to maintain. Further understanding of pellicle formation and environmental cues that influence cellular choices between these lifestyles will definitely improve our appreciation of bacterial interaction with their environments. Methods Shewanella oneidensis cells were cultured in 24-well plates with supplementation of varied divalent cations, and pellicles formed under such conditions were evaluated. Mutants defective in respiration of divalent cations were used to further characterize and confirm unique impacts of iron. Results and conclusions Small amount of Fe 2 + was essential for pellicle formation, but presence of over-abundant iron (0.3 mM Fe 2 + or Fe 3 + ) led to pellicle disassociation without impairing growth. Such impacts were found due to S. oneidensis -mediated formation of insoluble alternative electron acceptors (i.e., Fe 3 O 4 ) under physiologically relevant conditions. Furthermore, we demonstrated that cells preferred a lifestyle of forming biofilm and respiring on such insoluble electron acceptors under tested conditions, even to living in pellicles. General significance Our finding suggests that bacterial lifestyle choice involves balanced evaluation of multiple aspects of environmental conditions, and yet-to-be-characterized signaling mechanism is very likely underlying such processes.
研究领域:
微生物学
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环境科学
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PubMed
高影响因子
Surfaces and Interfaces
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2023
·
IF 6.2
Diandi Li,Haijun He,Zhongxuan Xu,Hong Deng
Coexistence of chromium and iron, manganese and copper in industries is common, which may affect the microbial treating efficiency and toxicity to microorganisms, thus restricting the application of microbial treatment technology. In this research, Cu 2+ promoted the reduction of Cr(VI) and the fixation of total chromium in bimetallic systems for both Shewanella oneidensis MR-1 and Bacillus subtilis , while Mn 2+ and Fe 3+ exhibited inhibition effects. Generally, groups with coexisting heavy metal of 0.1 mM were most affected, no matter promotive or inhibitive. Toxicity analysis revealed that high concentration of heavy metal ions led to damage to the cell membranes and reduction of their survival rate. To clarify the optimal condition for microbial treatment, response surface methodology was used to investigate the influencing factors of Cr(VI) reduction by S. oneidensis . The total chromium concentration in the supernatant was correlated with three factors, and the significant order of influence was: culture time > culture temperature > pH.
研究领域:
微生物学
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环境科学
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DOI
高影响因子
IET Nanobiotechnology
·
2018
·Vol. 12
·期 4
·441-445
·
IF 2.059
Xiaojie Song,Xianyang Shi,Mi Yang
Biosynthesised nanocomposites have attracted growing interests attributed to their ‘green’ synthesis nature in recent years. Shewanella oneidensis MR-1, a dissimilatory metal-reducing bacterium, was used to reduce palladium (II) nitrate to palladium (0) nanoparticles (Pd NPs) under anaerobic conditions, resulting in the in situ formation of Pd NPs immobilised on TiO 2 nanotubes (TNTs) (Pd/TNTs nanocomposites). The Pd/TNTs nanocomposites were characterised by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray, and electron spin resonance, respectively. The results indicated that Pd NPs are successfully grown on the TNTs without aggregation. Photocatalytic degradation of methylene blue (MB) by Pd/TNTs nanocomposites under simulated sunlight was also investigated. Pd/TNTs nanocomposites had photocatalytic efficiency superior to that of single TiO 2 nanomaterials. The photocatalytic activity of Pd/TNTs nanocomposites can be enhanced by S. oneidensis MR-1. The results showed that after only 10 min, the degradation ratio of MB reached 98.7% by Pd/TNTs nanocomposites when simultaneously assisted with S. oneidensis MR-1.
研究领域:
环境科学
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材料科学
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微生物学
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2024
·
IF 8
Mingxia Jiang,Yuyin Lin,Liyuan Xu,Zhihang Chen,Junxian Wu,Yong Yuan,Lihua Zhou
Extracellular respiratory bacteria (ERB) assume a significant role in biological and environmental remediation, so the rapid detection of ERB is essential to monitor its biological repair process. This study developed a microfluidic colorimetric biosensor for rapid and sensitive detection of ERB model strain Shewanella oneidensis MR-1. In the process of separation and enrichment of bacteria based on immune magnetic nanoparticles (MNPs), the biological signal is significantly amplified by the excellent peroxidase activity of flower-like CoOOH (FL-CoOOH). Firstly, immune MNPs, samples and immune FL-CoOOH were mixed and incubated within the microfluidic chip’s channel. Magnetic capture in the separation chamber yielded MNP-bacteria-CoOOH complex. Then, 3, 3′, 5, 5′-tetramethylbenzidine (TMB) substrate was added to make the FL-CoOOH nanozyme catalyze the formation of yellow product. Finally, the target bacteria in the microplate were quantitatively detected. Based on the excellent simulated enzyme activity and stability of FL-CoOOH, the detection can be completed within 45 min after the introduction of the microfluidic chip. The detection was 5×10 1 ∼5×10 6 CFU/mL. Compared with the previously reported colorimetric sensors for MR-1, the sensitivity was increased by 99.54 % to 23 CFU/mL. This study uniquely integrates optical sensors and microfluidic technology for rapid ERB detection with enhanced portability. The design of biosensor can facilitate further investigations into extracellular respiration mechanisms and rapid ecological environment restoration applications.
研究领域:
生物技术
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环境科学
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分析化学
·
微流控
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Cholnam Ri,Fengxiang Li,Hyokchol Mun,Linan Liu,Jingchun Tang
The technology of integrating sulfidated zero-valent iron and functional anaerobic bacteria has been extensively explored to improve the removal efficiency of pollutants and enhance the performance of anaerobic microbial system. In this study, the simultaneous DCNB(2,4-dichloronitrobenzene) reduction and methane production by ball-milled 1:1 Fe 0 /FeS 2 (briefly, 1:1 Fe 0 /FeS 2 ), Shewanella oneidensis MR-1 and microbial consortium (MC) were firstly investigated. The result showed that the DCNB reduction was increased by 2.6 and 1.7 times in 1:1 Fe 0 /FeS 2 + MR-1 group compared to 1:1 Fe 0 /FeS 2 and MR-1, respectively, while it further increased by almost 2 times in 1:1 Fe 0 /FeS 2 + MC + MR-1 group as compared to that of 1:1 Fe 0 /FeS 2 + MR-1 group. Moreover, the methane production was drastically facilitated via the reciprocal interaction among FeS as the reaction product, MR-1 and MC. Dechlorination was not found, mainly due to the inability of 1:1 Fe 0 /FeS 2 and the inexistence of dechlorinating bacteria in original inoculum. Meanwhile, the microbial community was also changed, with genera like Eubacterium capable of reducing nitroaromatic compound and Methanosarcina as acetoclastic methanogen enriched by 1:1 Fe 0 /FeS 2 and MR-1. Therefore, fast DCNB reduction and methane production using 1:1 Fe 0 /FeS 2 in anaerobic microbial system, gives useful reference for both establishment of pollutant removal and biogas production. In conclusion, Fe 0 /FeS 2 , as a kind of sulfidated ZVI, is a good candidate for enhancing both pollutant degradation and CH 4 production in anaerobic wastewater treatment.
研究领域:
环境工程
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微生物学
·
废水处理
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DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Siyu Zhang,Changdong Ke,Mengge Jiang,Yuancheng Li,Weilin Huang,Zhi Dang,Chuling Guo
Efficient remedies for living organisms including bacteria to counteract cadmium (Cd 2+ ) toxicity are still highly needed. Plant toxicity studies have showed that exogenous S(-II) (including hydrogen sulfide and its ionic forms, i.e., H 2 S, HS − , and S 2− ) application can effectively alleviate adverse effects of Cd stress, but whether S(-II) could mitigate bacterial Cd toxicity remains unclear. In this study, S(-II) was applied exogenously to Cd-stressed Shewanella oneidensis MR-1 and the results showed that S(-II) can significantly reactivate impaired physiological processes including growth arrest and enzymatic ferric (Fe(III) reduction inhibition. The efficacy of S(-II) treatment is negatively correlated with the concentration and time length of Cd exposure. Energy-dispersive X-ray (EDX) analysis suggested the presence of cadmium sulfide inside cells treated with S(-II). Both compared proteomic analysis and RT-qPCR showed that enzymes associated with sulfate transport, sulfur assimilation, methionine , and glutathione biosynthesis were up-regulated in both mRNA and protein levels after the treatment, indicating S(-II) may induce the biosynthesis of functional low-molecular-weight (LMW) thiols to counteract Cd toxicity. Meanwhile, the antioxidant enzymes were positively modulated by S(-II) and thus the activity of intracellular reactive oxygen species was attenuated. The study demonstrated that exogenous S(-II) can effectively alleviate Cd stress for S. oneidensis likely through inducing intracellular trapping mechanisms and modulating cellular redox status. It suggested that S(-II) may be a highly effective remedy for bacteria such as S. oneidensis under Cd-polluted environments.
研究领域:
微生物学
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环境科学
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生物化学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）