npj Biofilms and Microbiomes
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2020
·Vol. 6
·期 1
·1-12
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IF 7.067
Dong Yuhao,Li Shougang,Zhao Dan,Liu Jin,Ma Shuiyan,Geng Jinzhu,Lu Chengping,Liu Yongjie
Aeromonas hydrophila is the causative agent of motile Aeromonad septicemia in fish. Previous studies have shown that the myo -inositol metabolism is essential for the virulence of this bacterium. IolR is a transcription inhibitor that negatively regulates myo -inositol metabolic activity. While in the process of studying the inositol catabolism in A. hydrophila Chinese epidemic strain NJ-35, we incidentally found that ΔiolR mutant exhibited obvious autoaggregation and increased biofilm formation compared to the wild type. The role of surface proteins in A. hydrophila autoaggregation was confirmed by different degradation treatments. Furthermore, calcium promotes the formation of aggregates, which disappear in the presence of the calcium chelator EGTA. Transcriptome analysis, followed by targeted gene deletion, demonstrated that biofilm formation and autoaggregation caused by the inactivation of iolR was due to the increased transcription of a RTX-family adhesion gene, rmpA . Further, IolR was determined to directly regulate the transcription of rmpA . These results indicated that iolR is negatively involved in autoaggregation and biofilm formation in A. hydrophila , and this involvement was associated with its inhibition on the expression of rmpA .
研究领域:
微生物学
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分子生物学
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鱼类病理学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2017
·
IF 3.648
Jing Zhang,Taotao Fu,Chunying Zhu,Youguang Ma
Densities and viscosities of glycine, L-alanine, L-valine, L-threonine and L-arginine in aqueous (0.1–0.5) mol·kg − 1 myo -inositol solutions were measured at T = (293.15, 303.15, 313.15 and 323.15) K and p = 0.101 MPa. The volumetric properties such as the apparent molar volume ( V φ ), the limiting partial molar volume ( V φ 0 ), the limiting partial molar volumes of transfer (Δ tr V φ 0 ), the limiting apparent molar expansibility ( E 2 0 ), Hepler's constant and the isobaric thermal expansion coefficient ( α 2 ) were calculated through density. The viscometric properties such as the B -coefficient, the free energies of activation per mole of solvent (Δ μ 1 0 ≠ ) and solute (Δ μ 2 0 ≠ ) were obtained from the experimental viscosity data. The derived parameters hydration number and solvation number were also calculated through apparent molar volume and B -coefficient. From the volumetric and viscometric properties, the solute-solute and solute-solvent interactions in the studied systems were analyzed on the basis of co-sphere overlap model and transition state theory . Finally, the group contribution method was applied to calculate the contribution of (NH 3 + , COO − ), CH 2 , OH and CNHNHNH 2 of amino acids to V φ 0 , B -coefficient and Δ μ 2 0 ≠ .
研究领域:
物理化学
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热力学
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溶液化学
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DOI
高影响因子
CHEMICAL GEOLOGY
·
2026
·
IF 3.6
Yuan Qiu,Lisong Ma,Biao Wan,Xinran Liang,Shuai Lan,Guanjie Jiang,Yang Li,Qin Zhang,Yupeng Yan
Poorly crystalline iron hydroxides, such as ferrihydrite (Fh) and its aluminum-substituted counterpart (Al-substituted ferrihydrite, Al-Fh), are ubiquitous in surficial geochemical environments and undergo strong interfacial interactions with organic phosphorus (e.g., myo -inositol hexakisphosphate, phytate, IHP). However, how these interactions regulate the Fe(II)-catalyzed dissolution–recrystallization of Fh and Al-Fh into secondary Fe minerals and consequently influence phosphorus geochemical mobility and sequestration remains unclear. This study systematically investigated the Fe(II)-catalyzed transformation of phytate-preadsorbed Al-Fh via batch experiments and multiple characterizations to elucidate the regulatory role of phytate in governing Fe(II)-catalyzed Al-Fh transformation and phytate repartitioning. Results showed that isomorphous Al substitution inhibited goethite (Gt) nucleation in Fe(II)-catalyzed Al-Fh transformation by decreasing Al-Fh crystallinity and disrupting the periodic Fe–O–Fe crystal lattice arrangement. Fe(II) drove mineral dissolution and secondary phase nucleation via interfacial electron transfer (IET), with catalytic efficiency positively correlated with its concentration. Phytate exerted a concentration-dependent effect: at low concentration (0.5 mM), it impeded the further transformation of lepidocrocite (Lp) to Gt through strong inner-sphere surface complexation of phytate on reactive Fe sites, thereby favoring Lp mineral accumulation. At higher concentrations (≥1.0 mM), it greatly inhibited Al-Fh transformation via a combination of surface complexation, IET inhibition, reactive Fe(II) depletion, and the occupation of mineral dissolution sites, resulting in metastable Lp or amorphous products. Mechanistically, phytate formed stable complexes on Al-Fh surfaces, hindering electron transfer. Concurrently, phytate and Fe(II) generated ternary complexes (≡Fe–IHP–Fe(II)) or surface iron phytate precipitates on minerals, thereby depleting the reactive Fe(II) pool. Throughout transformation, phytate remained strongly sequestered in the solid phase rather than being released into solution due to its strong geochemical interactions with Fe/Al hydroxides. This work elucidates the synergistic regulatory mechanisms of Al and phytate in Al-Fh transformation, offering key theoretical insights into organic phosphorus–iron hydroxide interactions and long-term phosphorus immobilization in Al-rich soils.
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DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2018
·
IF 8.173
Kaige Zhao,Min Tang,Huaisheng Wang,Zhenxian Zhou,Yafeng Wu,Songqin Liu
An immunosensing biochip for simultaneous detection of three biomarkers related to acute myocardial infarction (AMI) was developed based on anionic soybean peroxidase (SBP) functionalized nanoprobe and chemiluminescent imaging. The nanoprobes (Ab2-SiO 2 -SBP) were fabricated by co-immobilization of SBP and one of the detection polyclonal antibodies , anti-cardiac troponin I antigen (anti-cTnI), anti-creatine kinase-MB (anti-CK-MB) and anti-myoglobin (anti-Myo), on the silica nanoparticle surface. The detection sensitivity was enhanced since the large surface area of silica carriers increased the loading of SBP for per sandwiched immunoreaction. The immunosensing biochip designed as 3 × 8 wells array was constructed by simultaneously immobilizing three capture monoclonal antibodies on the same one microtiter well with 2 × 3 active spots. In the presence of target protein, the nanoprobes will be attached onto the spots with high specificity through the sandwiched immunoreactions, which triggered the chemiluminescence (CL) signals on each sensing site of the microtiter plates and allowed to CL imaging of three biomarkers in one well at the same time. Therefore, the proposed biochip was a promising convenient strategy for simultaneous detection of cTnI, CK-MB and Myo, which showed potential application for multianalyte determination in clinical diagnostics.
研究领域:
生物医学工程
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临床诊断
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纳米技术
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免疫学
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产品关联
DOI
PubMed
高影响因子
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