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1.
Chem Soc Rev ; 53(9): 4707-4740, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38536022

RESUMEN

Millions of electric vehicles (EVs) on the road are powered by lithium-ion batteries (LIBs) based on nickel-rich layered oxide (NRLO) cathodes, and they suffer from a limited driving range and safety concerns. Increasing the Ni content is a key way to boost the energy densities of LIBs and alleviate the EV range anxiety, which are, however, compromised by the rapid performance fading. One unique challenge lies in the worsening of the microstructural stability with a rising Ni-content in the cathode. In this review, we focus on the latest advances in the understanding of NLRO microstructures, particularly the microstructural degradation mechanisms, state-of-the-art stabilization strategies, and advanced characterization methods. We first elaborate on the fundamental mechanisms underlying the microstructural failures of NRLOs, including anisotropic lattice evolution, microcracking, and surface degradation, as a result of which other degradation processes, such as electrolyte decomposition and transition metal dissolution, can be severely aggravated. Afterwards, we discuss representative stabilization strategies, including the surface treatment and construction of radial concentration gradients in polycrystalline secondary particles, the fabrication of rod-shaped primary particles, and the development of single-crystal NRLO cathodes. We then introduce emerging microstructural characterization techniques, especially for identification of the particle orientation, dynamic changes, and elemental distributions in NRLO microstructures. Finally, we provide perspectives on the remaining challenges and opportunities for the development of stable NRLO cathodes for the zero-carbon future.

2.
PLoS Genet ; 16(8): e1008569, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32810145

RESUMEN

Correct bioriented attachment of sister chromatids to the mitotic spindle is essential for chromosome segregation. In budding yeast, the conserved protein shugoshin (Sgo1) contributes to biorientation by recruiting the protein phosphatase PP2A-Rts1 and the condensin complex to centromeres. Using peptide prints, we identified a Serine-Rich Motif (SRM) of Sgo1 that mediates the interaction with condensin and is essential for centromeric condensin recruitment and the establishment of biorientation. We show that the interaction is regulated via phosphorylation within the SRM and we determined the phospho-sites using mass spectrometry. Analysis of the phosphomimic and phosphoresistant mutants revealed that SRM phosphorylation disrupts the shugoshin-condensin interaction. We present evidence that Mps1, a central kinase in the spindle assembly checkpoint, directly phosphorylates Sgo1 within the SRM to regulate the interaction with condensin and thereby condensin localization to centromeres. Our findings identify novel mechanisms that control shugoshin activity at the centromere in budding yeast.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Centrómero/metabolismo , Proteínas de Unión al ADN/metabolismo , Complejos Multiproteicos/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Secuencias de Aminoácidos , Proteínas Nucleares/química , Proteínas Nucleares/genética , Fosforilación , Unión Proteica , Proteína Fosfatasa 2/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética
3.
J Cell Sci ; 133(3)2020 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-31964708

RESUMEN

Owing to the local enrichment of factors that influence its dynamics and organization, the actin cytoskeleton displays different shapes and functions within the same cell. In yeast cells, post-Golgi vesicles ride on long actin cables to the bud tip. The proteins Boi1 and Boi2 (Boi1/2) participate in tethering and docking these vesicles to the plasma membrane. Here, we show in Saccharomyces cerevisiae that Boi1/2 also recruit nucleation and elongation factors to form actin filaments at sites of exocytosis. Disrupting the connection between Boi1/2 and the nucleation factor Bud6 impairs filament formation, reduces the directed movement of the vesicles to the tip and shortens the vesicles' tethering time at the cortex. Transplanting Boi1 from the bud tip to the peroxisomal membrane partially redirects the actin cytoskeleton and the vesicular flow towards the peroxisome, and creates an alternative, rudimentary vesicle-docking zone. We conclude that Boi1/2, through interactions with Bud6 and Bni1, induce the formation of a cortical actin structure that receives and aligns incoming vesicles before fusion with the membrane.


Asunto(s)
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Actinas/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Polaridad Celular , Exocitosis , Proteínas de Microfilamentos/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
4.
Soft Matter ; 18(8): 1617-1627, 2022 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-35108350

RESUMEN

Structural coloration in biomimetic nanostructures has remarkable application potential in vivid display devices, but their color change effect is still insufficiently competitive towards biology. Inspired by the feather color change of a hummingbird, a new methodology for coloration is proposed. A structure-colorable flexural artificial muscle (FlexAM) is developed by integrating a view-angle dependent photonic diffraction grating pattern and voltage-actuated dielectric elastomers as an electroactive entity via laminated object additive manufacturing. A multi-physics model is developed which guides the FlexAM to harness the view-angle dependence for the new coloration strategy. The electro-mechanochromic performances are experimentally characterized to verify the prediction of the multi-physics model. An ultrafast coloration in the FlexAM with an advancing figure-of-merit at a color-shift rate of 2.814 nm ms-1 is realized, in addition to an excellent fatigue resistance up to 10 000 cycles. A photonic display with arrayed FlexAM elements is designed, which can be used to display numbers and letters. The current research offers an advanced artificial muscle towards active photonic and visible strain sensing.


Asunto(s)
Nanoestructuras , Fotones , Biomimética/métodos , Elastómeros , Músculos , Nanoestructuras/química
5.
Opt Lett ; 45(11): 2957-2960, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32479432

RESUMEN

In this study, a new, to the best of our knowledge, form of odd-Pearcey Gauss beams with peculiar characteristics is presented. Compared with the Pearcey beam, the odd-Pearcey Gauss beam is symmetrical about the origin. At the initial stages, the odd-Pearcey Gauss beam propagates with a main central lobe and some residual spots that autofocus to the center, and then splits into two off-axis parabolic lobes after the autofocus finishes. Furthermore, we also introduce the soft well function to investigate the propagation profiles of the odd-Pearcey Gauss beams passing through it with different calibers and discuss the influence of the Gaussian waist width towards the focal distance and the propagation form of the odd-Pearcey Gauss beam. We also enumerate some potential and possible applications based on its peculiar characteristics.

6.
J Cell Sci ; 130(18): 2996-3008, 2017 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-28751498

RESUMEN

Eukaryotic cells can direct secretion to defined regions of their plasma membrane. These regions are distinguished by an elaborate architecture of proteins and lipids that are specialized to capture and fuse post-Golgi vesicles. Here, we show that the proteins Boi1p and Boi2p are important elements of this area of active exocytosis at the tip of growing yeast cells. Cells lacking Boi1p and Boi2p accumulate secretory vesicles in their buds. The essential PH domains of Boi1p and Boi2p interact with Sec1p, a protein required for SNARE complex formation and vesicle fusion. Sec1p loses its tip localization in cells depleted of Boi1p and Boi2p but overexpression of Sec1p can partially compensate for their loss. The capacity to simultaneously bind phospholipids, Sec1p, multiple subunits of the exocyst, Cdc42p and the module for generating active Cdc42p identify Boi1p and Boi2p as essential mediators between exocytosis and polar growth.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Membrana Celular/metabolismo , Polaridad Celular , Fusión de Membrana , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/metabolismo , Vesículas Secretoras/metabolismo , Proteínas Adaptadoras Transductoras de Señales/química , Secuencia de Aminoácidos , Prueba de Complementación Genética , Lípidos/química , Unión Proteica , Dominios Proteicos , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/ultraestructura , Proteínas de Saccharomyces cerevisiae/química , Vesículas Secretoras/ultraestructura , Proteína de Unión al GTP cdc42/metabolismo
7.
J Cell Sci ; 127(Pt 16): 3614-24, 2014 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-24895401

RESUMEN

Actomyosin ring (AMR) contraction and the synthesis of an extracellular septum are interdependent pathways that mediate cytokinesis in the yeast Saccharomyces cerevisiae and other eukaryotes. How these interdependent pathways are physically connected is central for understanding cytokinesis. The yeast IQGAP (Iqg1p) belongs to the conserved AMR. The F-BAR-domain-containing protein Hof1p is a member of a complex that stimulates cell wall synthesis. We report here on the stepwise formation of a physical connection between both proteins. The C-terminal IQ-repeats of Iqg1p first bind to the essential myosin light chain before both proteins assemble with Hof1p into the Mlc1p-Iqg1p-Hof1p (MIH) bridge. Mutations in Iqg1p that disrupt the MIH complex alter Hof1p targeting to the AMR and impair AMR contraction. Epistasis analyses of two IQG1 alleles that are incompatible with formation of the MIH complex support the existence and functional significance of a large cytokinetic core complex. We propose that the MIH complex acts as hinge between the AMR and the proteins involved in cell wall synthesis and membrane attachment.


Asunto(s)
Citocinesis , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Cadenas Ligeras de Miosina/genética , Cadenas Ligeras de Miosina/metabolismo , Unión Proteica , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Activadoras de ras GTPasa/genética , Proteínas Activadoras de ras GTPasa/metabolismo
8.
Adv Mater ; 36(16): e2311256, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38181436

RESUMEN

Due to low cost and high energy density, sodium metal batteries (SMBs) have attracted growing interest, with great potential to power future electric vehicles (EVs) and mobile electronics, which require rapid charge/discharge capability. However, the development of high-rate SMBs has been impeded by the sluggish Na+ ion kinetics, particularly at the sodium metal anode (SMA). The high-rate operation severely threatens the SMA stability, due to the unstable solid-electrolyte interface (SEI), the Na dendrite growth, and large volume changes during Na plating-stripping cycles, leading to rapid electrochemical performance degradations. This review surveys key challenges faced by high-rate SMAs, and highlights representative stabilization strategies, including the general modification of SMB components (including the host, Na metal surface, electrolyte, separator, and cathode), and emerging solutions with the development of solid-state SMBs and liquid metal anodes; the working principle, performance, and application of these strategies are elaborated, to reduce the Na nucleation energy barriers and promote Na+ ion transfer kinetics for stable high-rate Na metal anodes. This review will inspire further efforts to stabilize SMAs and other metal (e.g., Li, K, Mg, Zn) anodes, promoting high-rate applications of high-energy metal batteries towards a more sustainable society.

9.
J Med Chem ; 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39031770

RESUMEN

Synthetic α-galactosylceramide (αGalCer) and its analogues as powerful agonists for natural killer T (NKT) cell manipulation have received significant attention in immunotherapy and adjuvant development. However, identifying new potent NKT cell agonists, especially those with Th1 selectivity that promote anticancer effects, remains a challenging task. In this work, we introduced a sulfonamide group into the acyl chain of αGalCer to form additional hydrogen bonds to intensify the glycolipid/CD1d interaction. Two compounds GCS-11 and GCS-12 demonstrated remarkable potency while exhibiting different cytokine induction patterns. Compared to αGalCer, the Th1-biased GCS-11 exhibited a 6-fold increase in IFN-γ but not IL-4, while the Th1/2-balanced GCS-12 elicited 7- and 5-fold increase in IFN-γ and IL-4, respectively, in vivo. These findings place them among the most potent NKT cell agonists, with superior antitumor effects. Therefore, hydrogen-bond-involved derivatization could be a powerful strategy to develop potent and polarized NKT cell agonists for various immunotherapies.

10.
Front Plant Sci ; 15: 1348402, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38444536

RESUMEN

Introduction: The study addresses challenges in detecting cotton leaf pests and diseases under natural conditions. Traditional methods face difficulties in this context, highlighting the need for improved identification techniques. Methods: The proposed method involves a new model named CFNet-VoV-GCSP-LSKNet-YOLOv8s. This model is an enhancement of YOLOv8s and includes several key modifications: (1) CFNet Module. Replaces all C2F modules in the backbone network to improve multi-scale object feature fusion. (2) VoV-GCSP Module. Replaces C2F modules in the YOLOv8s head, balancing model accuracy with reduced computational load. (3) LSKNet Attention Mechanism. Integrated into the small object layers of both the backbone and head to enhance detection of small objects. (4) XIoU Loss Function. Introduced to improve the model's convergence performance. Results: The proposed method achieves high performance metrics: Precision (P), 89.9%. Recall Rate (R), 90.7%. Mean Average Precision (mAP@0.5), 93.7%. The model has a memory footprint of 23.3MB and a detection time of 8.01ms. When compared with other models like YOLO v5s, YOLOX, YOLO v7, Faster R-CNN, YOLOv8n, YOLOv7-tiny, CenterNet, EfficientDet, and YOLOv8s, it shows an average accuracy improvement ranging from 1.2% to 21.8%. Discussion: The study demonstrates that the CFNet-VoV-GCSP-LSKNet-YOLOv8s model can effectively identify cotton pests and diseases in complex environments. This method provides a valuable technical resource for the identification and control of cotton pests and diseases, indicating significant improvements over existing methods.

11.
Sci Data ; 11(1): 528, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38777888

RESUMEN

Due to the lack of direct assessment metrics, existing studies on the intensity of agricultural policies often utilize indicators such as Gross Domestic Product (GDP) of agriculture or the quantity of agricultural policies as measures. Optimizing methods for analyzing the intensity of agricultural policies will significantly impact parameter selection in agricultural policy research and the evaluation of policy effectiveness. In this study, we constructed a Chinese Agricultural Policy Corpus using agricultural policies released by various governmental agencies at the national level in China from 1982 to April 2023. We quantified the values of agricultural domain terms in the corpus and evaluated the intensity of each agricultural policy document. The validation results of this study indicate a strong correlation between the intensity of agricultural policies and agricultural GDP. The trend in agricultural GDP changes lags behind policy intensity by 2.5 years (at a 95% confidence level), thus validating the rationality of our constructed corpus, agricultural policy scoring dataset, and methodology.

12.
J Cell Sci ; 124(Pt 1): 35-46, 2011 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21118957

RESUMEN

We used a generally applicable strategy to collect and structure the protein interactions of the yeast type II protein phosphatase Ptc1p and its binding partner Nbp2p. The procedure transformed primary unstructured protein interaction data into an ensemble of alternative interaction states. Certain combinations of proteins are allowed in different network configurations. Nbp2p serves as the network hub and brings seven kinases in close contact to Ptc1p. As a consequence, the deletion of NBP2 affects several cellular processes including organelle inheritance and the responses to mating hormone, cell wall stress and high osmolarity; it also impairs the proper execution of the morphogenetic program. Our constraint interaction map provides a basis for understanding a subset of the observed phenotypes and assigns the Ptc1p-Nbp2p module a role in synchronizing the associated kinases during the cell cycle.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteína Fosfatasa 2/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas Adaptadoras Transductoras de Señales/química , Proteínas Adaptadoras Transductoras de Señales/genética , Unión Proteica , Mapeo de Interacción de Proteínas , Proteína Fosfatasa 2/química , Proteína Fosfatasa 2/genética , Estructura Terciaria de Proteína , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética
13.
Environ Microbiol ; 13(5): 1168-78, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21261799

RESUMEN

Alcanivorax dieselolei strain B-5 is a marine bacterium that can utilize a broad range of n-alkanes (C(5) -C(36) ) as sole carbon source. However, the mechanisms responsible for this trait remain to be established. Here we report on the characterization of four alkane hydroxylases from A. dieselolei, including two homologues of AlkB (AlkB1 and AlkB2), a CYP153 homologue (P450), as well as an AlmA-like (AlmA) alkane hydroxylase. Heterologous expression of alkB1, alkB2, p450 and almA in Pseudomonas putida GPo12 (pGEc47ΔB) or P. fluorescens KOB2Δ1 verified their functions in alkane oxidation. Quantitative real-time RT-PCR analysis showed that these genes could be induced by alkanes ranging from C(8) to C(36) . Notably, the expression of the p450 and almA genes was only upregulated in the presence of medium-chain (C(8) -C(16) ) or long-chain (C(22) -C(36) ) n-alkanes, respectively; while alkB1 and alkB2 responded to both medium- and long-chain n-alkanes (C(12) -C(26) ). Moreover, branched alkanes (pristane and phytane) significantly elevated alkB1 and almA expression levels. Our findings demonstrate that the multiple alkane hydroxylase systems ensure the utilization of substrates of a broad chain length range.


Asunto(s)
Alcanivoraceae/enzimología , Alcanos/metabolismo , Citocromo P-450 CYP4A/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Alcanivoraceae/genética , Clonación Molecular , Citocromo P-450 CYP4A/genética , Sistema Enzimático del Citocromo P-450/genética , Regulación Bacteriana de la Expresión Génica , Oxidación-Reducción , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/metabolismo , Pseudomonas putida/genética , Pseudomonas putida/metabolismo , Análisis de Secuencia de ADN , Especificidad por Sustrato
14.
J Cell Biol ; 220(7)2021 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-33929514

RESUMEN

During mitosis, sister chromatids attach to microtubules from opposite poles, called biorientation. Sister chromatid cohesion resists microtubule forces, generating tension, which provides the signal that biorientation has occurred. How tension silences the surveillance pathways that prevent cell cycle progression and correct erroneous kinetochore-microtubule attachments remains unclear. Here we show that SUMOylation dampens error correction to allow stable sister kinetochore biorientation and timely anaphase onset. The Siz1/Siz2 SUMO ligases modify the pericentromere-localized shugoshin (Sgo1) protein before its tension-dependent release from chromatin. Sgo1 SUMOylation reduces its binding to protein phosphatase 2A (PP2A), and weakening of this interaction is important for stable biorientation. Unstable biorientation in SUMO-deficient cells is associated with persistence of the chromosome passenger complex (CPC) at centromeres, and SUMOylation of CPC subunit Bir1 also contributes to timely anaphase onset. We propose that SUMOylation acts in a combinatorial manner to facilitate dismantling of the error correction machinery within pericentromeres and thereby sharpen the metaphase-anaphase transition.


Asunto(s)
Proteínas Portadoras/genética , Segregación Cromosómica/genética , Proteínas Nucleares/genética , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitina-Proteína Ligasas/genética , Cromátides/genética , Humanos , Cinetocoros , Mitosis/genética , Proteína Fosfatasa 2/genética , Saccharomyces cerevisiae/genética , Huso Acromático/genética , Sumoilación/genética
15.
Life Sci Alliance ; 3(9)2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32737079

RESUMEN

Cdc42 organizes cellular polarity and directs the formation of cellular structures in many organisms. By locating Cdc24, the source of active Cdc42, to the growing front of the yeast cell, the scaffold protein Bem1, is instrumental in shaping the cellular gradient of Cdc42. This gradient instructs bud formation, bud growth, or cytokinesis through the actions of a diverse set of effector proteins. To address how Bem1 participates in these transformations, we systematically tracked its protein interactions during one cell cycle to define the ensemble of Bem1 interaction states for each cell cycle stage. Mutants of Bem1 that interact with only a discrete subset of the interaction partners allowed to assign specific functions to different interaction states and identified the determinants for their cellular distributions. The analysis characterizes Bem1 as a cell cycle-specific shuttle that distributes active Cdc42 from its source to its effectors. It further suggests that Bem1 might convert the PAKs Cla4 and Ste20 into their active conformations.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteína de Unión al GTP cdc42/metabolismo , Proteínas Adaptadoras Transductoras de Señales/química , Proteínas Adaptadoras Transductoras de Señales/fisiología , Secuencia de Aminoácidos/genética , Ciclo Celular , Proteínas de Ciclo Celular/química , División Celular , Polaridad Celular , Factores de Intercambio de Guanina Nucleótido/metabolismo , Unión Proteica/fisiología , Proteínas Serina-Treonina Quinasas/química , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiología , Saccharomycetales/metabolismo , Proteína de Unión al GTP cdc42/genética , Proteína de Unión al GTP cdc42/fisiología , Proteína de Unión al GTP cdc42 de Saccharomyces cerevisiae/genética , Proteína de Unión al GTP cdc42 de Saccharomyces cerevisiae/metabolismo
16.
J Vet Sci ; 20(6): e74, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31775200

RESUMEN

As an important zoonotic pathogen, Staphylococcus aureus has led to serious mastitis and endometritis in infected dairy cows. In this study, a total of 164 strains of S. aureus were isolated from dairy cows in Xinjiang Province, China, and subjected to assays to determine drug susceptibility and biofilm (BF) formation ability. Enterotoxin-related genes were detected, and the transcription levels of genes related to BF formation were determined by using reverse transcription-quantitative polymerase chain reaction. Moreover, the pathogenicity of isolates with different BF formation abilities was determined by measuring their hemolysis activity, half lethal dose (LD50) and organ bacterial load. The results showed that 86.0% of S. aureus isolates could form BF. Among them, 42.1% of the strains had weak BF formation ability, and most strains with a strong BF formation ability were ica gene carriers. The S. aureus isolates displayed multidrug resistance and their drug resistance was positively correlated with their BF formation ability. Moreover, 96.3% of the S. aureus isolates carried enterotoxin genes. Among them, the detection rates of the novel enterotoxin genes were higher than those of conventional enterotoxin genes. Furthermore, isolates with a strong BF formation ability had higher LD50 but lower hemolysis ability and organ bacterial load than those of the isolates with weak or no BF ability. However, isolates without BF ability produced more severe pathological changes than those of isolates with strong BF formation ability. These findings suggest that higher BF ability and presence of novel enterotoxin genes are important characteristics of S. aureus isolates from dairy cows in Xinjiang Province, China, and such isolates may pose potential threats to food safety.


Asunto(s)
Biopelículas , Enfermedades de los Bovinos/microbiología , Farmacorresistencia Bacteriana/genética , Enterotoxinas/química , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus/fisiología , Staphylococcus aureus/patogenicidad , Animales , Antibacterianos/farmacología , Bovinos , China , Industria Lechera , Femenino , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Virulencia
17.
Int J Syst Evol Microbiol ; 59(Pt 6): 1474-9, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19502338

RESUMEN

A taxonomic study was carried out on strain A-11-3(T), which was isolated from an oil-enriched consortia from the surface seawater of Hong-Deng dock in the Straits of Malacca and Singapore. Cells were aerobic, Gram-negative, non-spore-forming irregular rods. The strain was catalase- and oxidase-negative. It grew on a restricted spectrum of organic compounds, including some organic acids and alkanes. 16S rRNA gene sequence comparisons showed that strain A-11-3(T) was most closely related to the type strains of Alcanivorax jadensis (96.8 % sequence similarity), Alcanivorax borkumensis (96.8 %), Alcanivorax dieselolei (94.8 %), Alcanivorax venustensis (94.2 %) and Alcanivorax balearicus (94.0 %). The predominant fatty acids were C(16 : 0) (31.2 %), C(18 : 1)omega7c (24.8 %), C(18 : 0) (9.6 %), C(12 : 0) (8.3 %), C(16 : 1)omega7c (8.3 %) and C(16 : 0) 3-OH (5.1 %). The G+C content of the genomic DNA was 54.7 mol%. Moreover, the strain produced lipopeptides as its surface-active compounds. According to physiological and biochemical tests, DNA-DNA hybridization results and sequence comparisons of the 16S-23S internal transcribed spacer, the gyrB gene and the alkane hydroxylase gene alkB1, strain A-11-3(T) was affiliated with the genus Alcanivorax but could be readily distinguished from recognized Alcanivorax species. Therefore strain A-11-3(T) represents a novel species of the genus Alcanivorax for which the name Alcanivorax hongdengensis sp. nov. is proposed. The type strain is A-11-3(T) (=CGMCC 1.7084(T)=LMG 24624(T)=MCCC 1A01496(T)).


Asunto(s)
Alcanivoraceae/clasificación , Alcanos/metabolismo , Lipopéptidos/biosíntesis , Agua de Mar/microbiología , Alcanivoraceae/genética , Alcanivoraceae/aislamiento & purificación , Alcanivoraceae/fisiología , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Composición de Base , Biodegradación Ambiental , China , ADN Bacteriano/análisis , ADN Espaciador Ribosómico/análisis , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Fenotipo , Filogenia , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 16S/genética , ARN Ribosómico 23S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Tensoactivos/metabolismo
18.
Int J Syst Evol Microbiol ; 57(Pt 2): 316-320, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17267971

RESUMEN

Two bacterial strains, M-5T and WP0211T, were isolated from the surface water of a waste-oil pool in a coastal dock and from a deep-sea sediment sample from the West Pacific Ocean, respectively. Analysis of 16S rRNA gene sequences indicated that both strains belonged to the class Alphaproteobacteria and were closely related to Thalassospira lucentensis (96.1 and 96.2 %, gene sequence similarity, respectively). Based on the results of physiological and biochemical tests, as well as DNA-DNA hybridization experiments, it is suggested that these isolates represent two novel species of the genus Thalassospira. Various traits allow both novel strains to be differentiated from Thalassospira lucentensis, including oxygen requirement, nitrate reduction and denitrification abilities and major fatty acid profiles, as well as their ability to utilize six different carbon sources. Furthermore, the novel strains may be readily distinguished from each other by differences in their motility, flagellation, growth at 4 degrees C and 40 degrees C, their ability to hydrolyse Tween 40 and Tween 80, their utilization of 19 different carbon sources and by quantitative differences in their fatty acid contents. It is proposed that the isolates represent two novel species for which the names Thalassospira xiamenensis sp. nov. (type strain, M-5T=DSM 17429T=CGMCC 1.3998T) and Thalassospira profundimaris sp. nov. (type strain, WP0211T=DSM 17430T=CGMCC 1.3997T) are proposed.


Asunto(s)
Sedimentos Geológicos/microbiología , Rhodospirillaceae/clasificación , Rhodospirillaceae/aislamiento & purificación , Agua de Mar/microbiología , Técnicas de Tipificación Bacteriana , Metabolismo de los Hidratos de Carbono , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Ácidos Grasos/química , Flagelos , Genes de ARNr , Datos de Secuencia Molecular , Movimiento , Nitratos/metabolismo , Oxidación-Reducción , Océano Pacífico , Filogenia , Polisorbatos , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Rhodospirillaceae/genética , Rhodospirillaceae/fisiología , Análisis de Secuencia de ADN , Temperatura
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