Ruthenium red and alcian blue effects on outer structures of methanotrophic bacteria

Methane, a contributor to the “greenhouse effect”, is oxidized in the natural environment by methanotrophic bacteria. As part of a comprehensive research effort, we have been examining the ultrastructure of methanotrophs. These microorganisms have complex outer cell wall structures similar to those frequently found in other chemol itho- trophic bacteria. (1,2)In our work, we have focused on the “type” strains of Methylomonas albus BG8 and Methylosinus trichosporium OB3b. Between Spurr and LR White embedding resins, we found a difference 1n the preservation of an outer cup layer of BG8 external to the peripheral membranes. Cells from the same sample embedded in Spurr consistently lacked this feature (FIG. 1). This effect was overcome by an en bloc ruthenium red (RR) protocol that resulted in successful retention of the cup layer in Spurr resin (FIG. 2). For OB3b cells, the en bloc RR protocol resulted in an exterior bead feature distinguishable in thin section (FIG. 4) that previously was seen only by SEM.

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Enhancement of outer cell layers of a methanotrophic bacterium using uranyl acetate en bloc

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102456 ◽

1988 ◽

Vol 46 ◽

pp. 74-75

Author(s):

K. Putzer ◽

T.A. Fassel ◽

C.C. Remsen

Keyword(s):

Uranyl Acetate ◽

Outer Cell ◽

Type I ◽

Type Ii ◽

En Bloc ◽

Wall Structures ◽

Intracytoplasmic Membranes ◽

Cell Layers ◽

Ethanol Series ◽

Autotrophic Microorganisms

Obligate methanotrophic bacteria are autotrophic microorganisms capable of oxidizing methane to supply both their carbon and energy requirements. Methanotrophs are placed in one of two groups based on certain biochemical features and the arrangement of intracytoplasmic membranes (ICM). Type I methanotrophs contain ICM arranged as bundles of disc-like vessicles in the interior of the cell, while Type II methanotrophs display paired peripheral ICM. The organism used in this study, Methylosinus trichosporium OB3b, is a Type II methanotroph and has a capsular structure surrounding the cell as well as several complex cell wall structures described as cup-like, filamentous, and spike-shaped. This study examines the external surface of M. trichosporium OB3b following en bloc staining with uranyl acetate.Cells were harvested in mid-log phase, fixed in 0.5% glutaraldehyde and postfixed in 1% OsO4. Cells were enrobed in 4% agar prior to dehydration in a graded ethanol series.

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Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128274 ◽

1987 ◽

Vol 45 ◽

pp. 792-793

Author(s):

T.A. Fassel ◽

M.J. Schaller ◽

M.E. Lidstrom ◽

C.C. Remsen

Keyword(s):

Cytoplasmic Membrane ◽

Structural Features ◽

Methylotrophic Bacteria ◽

Type I ◽

Type Ii ◽

Membrane Complex ◽

Oxidation Of Methane ◽

Methane Oxidizing Bacteria ◽

Wall Structures ◽

Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

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The ultrastructure of the outer cell wall-layer ofChlorella mutants with and without sporopollenin

Plant Systematics and Evolution ◽

10.1007/bf00984613 ◽

1981 ◽

Vol 138 (1-2) ◽

pp. 121-137 ◽

Cited By ~ 24

Author(s):

J. Burczyk ◽

M. Hesse

Keyword(s):

Cell Wall ◽

Wall Layer ◽

Outer Cell ◽

Cell Wall Layer ◽

Outer Cell Wall

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A freeze-etch study of plant cell walls for ectodesmata

Canadian Journal of Botany ◽

10.1139/b74-260 ◽

1974 ◽

Vol 52 (9) ◽

pp. 2033-2036 ◽

Cited By ~ 7

Author(s):

N. C. Lyon ◽

W. C. Mueller

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Leaf Tissue ◽

Physicochemical Characteristics ◽

Outer Cell ◽

Plantago Major ◽

Plant Cell Walls ◽

Phaseolus Vulgaris L ◽

Epidermal Cell Wall ◽

Outer Cell Wall

Leaf tissue of Phaseolus vulgaris L. and Plantago major L. was prepared by the freeze-etch technique and examined in the electron microscope for the presence of ectodesmata. No structures analagous to ectodesmata observed with light microscopy could be found in freeze-etched preparations of chemically unfixed material or in material fixed only in glutaraldehyde. Objects appearing as broad, shallow, granular areas in the epidermal cell wall beneath the cuticle were observed in leaf replicas after fixation in complete sublimate fixative, the acid components of the sublimate fixative, or mercuric chloride alone. Because of their distribution and location, these objects can be considered analagous to ectodesmata observed by light microscopists. Because these areas occur only in chemically fixed walls and are localized within the walls in discrete areas, their presence supports the contention that ectodesmata are sites in the outer cell wall with defined physicochemical characteristics.

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Spreading of a mycobacterial cell-surface lipid into host epithelial membranes promotes infectivity

eLife ◽

10.7554/elife.60648 ◽

2020 ◽

Vol 9 ◽

Author(s):

CJ Cambier ◽

Steven M Banik ◽

Joseph A Buonomo ◽

Carolyn R Bertozzi

Keyword(s):

Cell Wall ◽

Cell Surface ◽

Immune Activation ◽

Cholesterol Synthesis ◽

Membrane Lipids ◽

Preventive Therapy ◽

Outer Cell ◽

Surface Lipid ◽

Epithelial Membranes ◽

Outer Cell Wall

Several virulence lipids populate the outer cell wall of pathogenic mycobacteria. Phthiocerol dimycocerosate (PDIM), one of the most abundant outer membrane lipids, plays important roles in both defending against host antimicrobial programs and in evading these programs altogether. Immediately following infection, mycobacteria rely on PDIM to evade Myd88-dependent recruitment of microbicidal monocytes which can clear infection. To circumvent the limitations in using genetics to understand virulence lipids, we developed a chemical approach to track PDIM during Mycobacterium marinum infection of zebrafish. We found that PDIM's methyl-branched lipid tails enabled it to spread into host epithelial membranes to prevent immune activation. Additionally, PDIM’s affinity for cholesterol promoted this phenotype; treatment of zebrafish with statins, cholesterol synthesis inhibitors, decreased spreading and provided protection from infection. This work establishes that interactions between host and pathogen lipids influence mycobacterial infectivity and suggests the use of statins as tuberculosis preventive therapy by inhibiting PDIM spread.

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Changes in structure of red pepper (Capsicum annuum L.) seedlings shoots under aluminum stress conditions

Acta Agrobotanica ◽

10.5586/aa.2007.010 ◽

2012 ◽

Vol 60 (1) ◽

pp. 85-93 ◽

Cited By ~ 2

Author(s):

Agata Konarska

Keyword(s):

Cell Wall ◽

Capsicum Annuum ◽

Red Pepper ◽

Outer Cell ◽

Aluminum Stress ◽

Water Culture ◽

Anatomical Features ◽

Parenchyma Cells ◽

Al Treatment ◽

Outer Cell Wall

The seedlings of the red pepper (Capsicum annuum L.) cv. Trapez grown in water culture for a period of 14 days with Al (0, 10, 20 and 40 mg·dm-3 AlCl3·6 H2O). Some morphological and anatomical features of red pepper shoots were analyzed. Reduction in height and diameter of stems as well as decrease in fresh mass of shoots were observed after Al-treatment. In the hypocotyl the thickness of cortex parenchyma layer and the size of their cells were reduced. The aluminum treatment resulted in the increased in thickness of the epidermis outer cell wall. Under Al stress in the cotrex and the central cylinder parenchyma cells were present numerous enlarge plastids which contained large grains of starch and dark little bodies which were possible aluminum deposits. They weren`t observed in control seedlings.

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Anatomical and Histochemical Effects of Feeding by Citrus Leafminer Larvae (Phyllocnistis citrella Stainton) in Citrus Leaves

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.122.6.829 ◽

1997 ◽

Vol 122 (6) ◽

pp. 829-836 ◽

Cited By ~ 15

Author(s):

D.S. Achor ◽

H. Browning ◽

L.G. Albrigo

Keyword(s):

Callus Tissue ◽

Light And Electron Microscopy ◽

Outer Cell ◽

Phyllocnistis Citrella ◽

Microbial Invasion ◽

Citrus Leafminer ◽

Wound Recovery ◽

Citrus Leaves ◽

Tissue Recovery ◽

Outer Cell Wall

Young expanding leaves of `Ambersweet' [Citrus reticulata Blanco × C. paradisi Macf. × C. reticulata) × C. sinensis (L) Osb.] with feeding injury by third larval stage of citrus leafminer (Phyllocnistis citrella) were examined by light and electron microscopy for extent of injury and tissue recovery over time. Results confirmed that injury is confined to the epidermal layer, leaving a thin covering over the mine tunnel that consisted of the cuticle and outer cell wall. Wound recovery consisted of two possible responses: the production of callus tissue or the formation of wound periderm. The production of callus tissue developed within 3 days of injury when the uninjured palisade or spongy parenchyma below the injured epidermis produced callus tissue through periclinal or diagonal cell divisions. After 1 month, the entire epidermis was replaced by callus tissue. In the absence of secondary microbial invasion, this callus tissue developed a thick cuticle, followed by development of a covering of platelet wax after 4 months. Alternatively, wound periderm formed if the outer cuticular covering was torn before the cuticle had developed sufficiently to prevent the exposed cells from being desiccated or invaded by fungi, bacteria, or other insects. The wound periderm consisted of a lignified layer of collapsed callus cells, a suberized phellem layer, and a multilayered phelloderm-phellogen. Since there were always cellular collapse or fungi and bacteria associated with wound periderm formation, it was determined to be a secondary effect, not a direct effect of leafminer feeding.

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Silver nanoparticles (AgNPs) internalization and passage through the Lactuca sativa (Asteraceae) outer cell wall

Functional Plant Biology ◽

10.1071/fp21161 ◽

2021 ◽

Author(s):

Sergimar Kennedy de Paiva Pinheiro ◽

Thaiz Batista Azevedo Rangel Miguel ◽

Marlos de Medeiros Chaves ◽

Francisco Claudio de Freitas Barros ◽

Camila Pessoa Farias ◽

...

Keyword(s):

Silver Nanoparticles ◽

Cell Wall ◽

Lactuca Sativa ◽

Outer Cell ◽

Outer Cell Wall

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Fluorescence recovery after photobleaching reveals that LPS rapidly transfers from CD14 to hsp70 and hsp90 on the cell membrane

Journal of Cell Science ◽

10.1242/jcs.114.13.2535 ◽

2001 ◽

Vol 114 (13) ◽

pp. 2535-2545

Author(s):

Kathy Triantafilou ◽

Martha Triantafilou ◽

Shab Ladha ◽

Alan Mackie ◽

Russell L. Dedrick ◽

...

Keyword(s):

Fluorescence Recovery After Photobleaching ◽

Lipoteichoic Acid ◽

Fluorescence Recovery ◽

Outer Cell ◽

Immune Recognition ◽

Gram Positive Bacteria ◽

Innate Recognition ◽

Functional Receptor ◽

Attachment Process ◽

Outer Cell Wall

Although CD14 has been implicated in the immune recognition of bacterial lipopolysaccharide (LPS) from Gram-negative bacteria and also peptidoglycan (PGN) and lipoteichoic acid (LTA) from the outer cell wall of Gram-positive bacteria, accumulating evidence has suggested the possible existence of other functional receptor(s). In this study, we have used fluorescence recovery after photobleaching (FRAP) in order to get the first dynamic picture of the innate recognition of bacteria. We have found that the diffusion coefficient of CD14 remains unaffected after LPS ligation and that the diffusion coefficients of FITC-LPS and FITC-LTA bound to cells differ from that of CD14. Furthermore, FITC-LPS/LTA rapidly become immobile when bound to cells, suggesting that FITC-LPS/LTA must briefly associate with CD14 in the initial attachment process and rapidly move on to an immobile receptor or to a complex of receptors. Further FRAP experiments revealed that heat shock protein 70 (hsp70) and hsp90 are immobile in cell membranes, and antibodies against them were found to block the transfer of LPS to the immobile receptor and to inhibit interleukin 6 production upon LPS stimulation. These experiments indicated that LPS transfers from CD14 to hsp70 and hsp90, which may be part of an LPS/LTA multimeric receptor complex. Thus, hsps are implicated as mediators of the innate activation by bacteria.

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