ENVIRONMENTAL RESEARCH
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2020
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IF 5.715
Zhen-Ni Yang,Ya-Nan Hou,Bo Zhang,Hao-Yi Cheng,Yang-Chun Yong,Wen-Zong Liu,Jing-Long Han,Shuang-Jiang Liu,Ai-Jie Wang
Biologically synthesized palladium nanoparticles (bio-Pd) have attracted considerable interest as promising green catalysts for environmental remediation. However, the mechanisms by which microorganisms produce bio-Pd remain unclear. In the present study, we investigated the roles of Shewanella oneidensis MR-1 and its NADH dehydrogenases and hydrogenases (HydA and HyaB) in bio-Pd production using formate as the electron donor. The roles of NADH dehydrogenases and hydrogenases were studied by inhibiting NADH dehydrogenases and using hydrogenase mutants (Δ hydA , Δ hyaB , and Δ hydA Δ hyaB ), respectively. The results showed ~97% reduction of palladium by S. oneidensis MR-1 after 24 h using 250 μM palladium and 500 μM formate. Electron microscopy images showed the presence of bio-Pd on both the outer and cytoplasmic membranes of S. oneidensis MR-1. However, the inhibition of NADH dehydrogenases in S. oneidensis MR-1 resulted in only ~61% reduction of palladium after 24 h, and bio-Pd were not found on the outer membrane. The mutants lacking one or two hydrogenases removed 91–96% of palladium ions after 24 h and showed more cytoplasmic bio-Pd but less periplasmic bio-Pd. To the best of our knowledge, this is the first study to demonstrate the role of NADH dehydrogenases of S. oneidensis MR-1 in the formation of bio-Pd on the outer membrane. It also demonstrates that the hydrogenases (especially HyaB) of S. oneidensis MR-1 contribute to the formation of bio-Pd in the periplasmic space. This study provides mechanistic insights into the production of biogenic metal nanoparticles towards their possible use in industrial and environmental applications.
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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产品关联
DOI
PubMed
高影响因子
MOLECULES
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2024
·Vol. 29
·期 10
·2354
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IF 4.2
Jia-Le Zhou,Hao-Han Chen,Jian Xu,Ming-Yu Huang,Jun-Feng Wang,Hao-Jie Shen,Sheng-Xiang Shen,Cheng-Xian Gao,Chao-Dong Qian
Background:Staphylococcus aureusis a common pathogenic microorganism in humans and animals. Type II NADH oxidoreductase (NDH-2) is the only NADH:quinone oxidoreductase present in this organism and represents a promising target for the development of anti-staphylococcal drugs. Recently, myricetin, a natural flavonoid from vegetables and fruits, was found to be a potential inhibitor of NDH-2 ofS. aureus. The objective of this study was to evaluate the inhibitory properties of myricetin against NDH-2 and its impact on the growth and expression of virulence factors inS. aureus. Results: A screening method was established to identify effective inhibitors of NDH-2, based on heterologously expressedS. aureusNDH-2. Myricetin was found to be an effective inhibitor of NDH-2 with a half maximal inhibitory concentration (IC50) of 2 μM. In silico predictions and enzyme inhibition kinetics further characterized myricetin as a competitive inhibitor of NDH-2 with respect to the substrate menadione (MK). The minimum inhibitory concentrations (MICs) of myricetin againstS. aureusstrains ranged from 64 to 128 μg/mL. Time–kill assays showed that myricetin was a bactericidal agent againstS. aureus. In line with being a competitive inhibitor of the NDH-2 substrate MK, the anti-staphylococcal activity of myricetin was antagonized by MK-4. In addition, myricetin was found to inhibit the gene expression of enterotoxin SeA and reduce the hemolytic activity induced byS. aureusculture on rabbit erythrocytes in a dose-dependent manner. Conclusions: Myricetin was newly discovered to be a competitive inhibitor ofS. aureusNDH-2 in relation to the substrate MK. This discovery offers a fresh perspective on the anti-staphylococcal activity of myricetin.
研究领域:
微生物学
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药理学
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生物化学
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DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2022
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IF 5.304
Li Fu,Qingmei Chen,Suqi Deng,Li Jia
An economical and label-free fluorescent sensor was developed for the selective detection of Escherichia coli ( E. coli ) based on the competitive reduction of Cu 2+ in CuFe 2 O 4 magnetic particles (MPs) by E. coli and o -phenylenediamine (OPD). Cu 2+ in CuFe 2 O 4 MPs can oxidize OPD to generate 2,3-diaminophenazine (OPDox) with fluorescent property. The presence of E. coli can weaken the oxidative ability of CuFe 2 O 4 MPs toward OPD owing to the copper reductase activity of NADH dehydrogenase-2 (NDH-2) in E. coli . NDH-2 can reduce Cu 2+ to Cu + , thereby inhibiting the OPD oxidation and resulting in the decrease of the fluorescence of the system. Under the optimum conditions, the fluorescent sensor exhibited a wide linear response to E. coli in the concentration range of 10 3 – 10 6 cfu mL −1 , and the detection limit was calculated to be 5.8 × 10 2 cfu mL −1 . Furthermore, the feasibility of the sensor was verified by successful detection of E. coli in popsicle and swimming pool water samples. More importantly, the sensor utilized the magnetic property of CuFe 2 O 4 MPs to realize the phase separation, thus averting the interference of other impurities in the sample matrix.
研究领域:
分析化学
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生物技术
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环境科学
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微生物学
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产品关联
DOI
高影响因子
CHEMOSPHERE
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2022
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IF 8.943
Jinghao Wang,Huimin Liu,Song Song,Yuancai Chen,Yongyou Hu
Microbial electron output capacity is critical for organic contaminants biodegradation. Herein, original C. freundii JH could oxidate formate in anaerobic respiration, but lack the ability to degrade sulfamethoxazole (SMX). While the incorporation of Pd(0) could effectively improve the electron output via improving the combination between flavins and c-type cytochromes (c-Cyts), increasing the activities of key enzymes (formate dehydrogenase , hydrogenase, F 0 F 1 -ATPases), etc. More importantly, the presence of Pd(0) caused the NADH dehydrogenase (complex I) nearly in idle, and triggered the decrease of NADH/NAD + ratio and increase of H + -efflux transmembrane gradient, eventually resulting in the electrons diverting from CoQ-involved long respiratory chain (decreasing from 91.67% to 36.25%) to FDH/Hases-based hydrogen-producing short chain (increasing from 22.44% to 84.88%), which further intensified the electron output. Above changes effectively launched and guaranteed the high-level SMX degradation by palladized C. freundii JH, alleviating the ecotoxicity of SMX in aquatic and terrestrial environments. These conclusions provided the new view to regulate the microbial electron output behaviors.
研究领域:
环境微生物学
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生物修复
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电子传递
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环境毒理学
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产品关联
DOI
PubMed
高影响因子
Journal of Functional Foods
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2019
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IF 3.197
Zhenlong Chen,Yuhui Yang,Shumei Mi,Qingsheng Fan,Xiaoming Sun,Baichuan Deng,Guoyao Wu,Yafei Li,Quancheng Zhou,Zheng Ruan
Chlorogenic acid (CGA) is a type of phenolic acid that has antioxidant and anti-inflammatory activities. In this study, we investigated the hepatoprotective effect of CGA in lipopolysaccharide (LPS)-treated rats. Supplementation with CGA attenuated ( P < 0.05) hepatocyte necrosis and inflammatory cell infiltration, decreased ( P < 0.05) the activities of serum transaminases and alkaline phosphatase and the level of total bilirubin, and increased ( P < 0.05) the level of serum total protein in comparison with the LPS-only group. In addition, CGA potently inhibited ( P < 0.05) the LPS-induced drop in the activities of mitochondrial NADH dehydrogenase and ATP synthase and the contents of ATP and AMP in the liver. Furthermore, CGA could partially counteract the changes induced by lipopolysaccharide in many metabolic pathways, such as energy metabolism, amino acid metabolism, and glutathione metabolism. In summary, our study showed that CGA supplementation had a protective effect against LPS-induced chronic liver injury.
研究领域:
药理学
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肝病学
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免疫学
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代谢学
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DOI
高影响因子
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