Spheroplasts of Methanospirillum hungatii formed upon treatment with dithiothreitol

1979 ◽  
Vol 25 (6) ◽  
pp. 730-738 ◽  
Author(s):  
G. D. Sprott ◽  
J. R. Colvin ◽  
R. C. McKellar
Keyword(s):  
Cell Wall ◽  
Attachment Site ◽  
Outer Wall ◽  
Methanogenic Bacteria ◽  
Methanosarcina Barkeri ◽  
Outer Cell ◽  
Alkaline Ph ◽  
Adhesive Material ◽  
Thin Sections ◽  
Outer Cell Wall

Strains of Methanospirillum hungatii, when treated with dithiothreitol at alkaline pH, formed spheroplasts which lysed in the absence of an osmotic stabilizer. Other methanogenic bacteria showed no response to this treatment, including Methanobacterium thermoautotrophicum. Methanobacterium strain M.o.H., Methanobacterium strain G2R, and Methanosarcina barkeri. The reaction with M. hungatii proceeded slowly at pH 8.0, but increased dramatically up to a pH of 10. Spheroplasts did not form in the presence of MgCl2 or if large amounts of FeS precipitate had been deposited on the cells during growth. Ultra-thin sections of M. hungatii GPI confirmed that individual cells, surrounded by a membrane and an inner wall, were contained within an outer wall or sheath. Adhesive material, which stained in the region of the cell spacer, was observed to bind together the inner and outer wall layers. After treatment with dithiothreitol, the spheroplasts, which retained the flexible inner wall and membrane, were released from the rigid outer wall. Examination of the isolated outer cell wall revealed that dithiothreitol (and dodecyl sodium sulfate) dissolved the adhesive material and damaged the cell spacer at the attachment site to the outer wall. It is proposed that dithiothreitol at alkaline pH loosens both the cell spacer and inner wall attachments to the outer wall, thereby allowing the osmotic pressure of the cytoplasm to eject the spheroplast. Resistance of the cells to lysis by Triton X-100 is lost upon spheroplast formation, indicating that protection to the cell is conferred by the outer cell wall.

scholarly journals The comparison of nectaries structure of some varieties of ornamental apple

2012 ◽  
Vol 60 (1) ◽  
pp. 35-43
Author(s):  
Agata Konarska
Keyword(s):  
Cell Wall ◽  
Light Microscope ◽  
Outer Wall ◽  
Epidermal Cells ◽  
Outer Cell ◽  
Glandular Tissue ◽  
Floral Nectary ◽  
Apple Cultivars ◽  
Outer Cell Wall ◽  
Scanning Electron

The study of floral nectary structures of thirteen ornamental apple cultivars examined using light microscope (MS) and scanning electron microscope (SEM) was performed. It was found that nectary glands in the selected cultivars were located in the upper part of the flower receptacle, between the ovary of the pistil and the base of stamen filaments, and they generally belonged to the epimorphic or transitoric type. The nectary surface area, its thickness, the number of glandular tissue layers, the height of epidermal cells of the nectary and the thickness of the outer wall of the epidermis, together with the cuticle, were determined by light microscope. By using SEM, the structure of the surface of nectaries in four ornamental apple cultivars was observed. The epidermis of the upper part of the nectaries was composed of elongated cells of which outer cell wall was covered with a striated cuticle. The remaining part of the nectary was characterised by cells of similar arrangement and shape, but their surface was marked by a thinner and smoother layer of cuticle. Closed or opened stomata were generally situated at the level of the epidermal cells. Their pores were often filled with granular or plate-shaped structures.

A freeze-etch study of plant cell walls for ectodesmata

1974 ◽  
Vol 52 (9) ◽  
pp. 2033-2036 ◽  
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.

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

eLife ◽  
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.

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

2012 ◽  
Vol 60 (1) ◽  
pp. 85-93 ◽  
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 (<i>Capsicum annuum</i> L.) cv. Trapez grown in water culture for a period of 14 days with Al (0, 10, 20 and 40 mg·dm<sup>-3</sup> AlCl<sub>3</sub>·6 H<sub>2</sub>O). 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.

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

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

Production of Monoclonal Antibodies Against the Outer Cell Wall ofClostridium tyrobutyricum

Hybridoma ◽  
1994 ◽  
Vol 13 (1) ◽  
pp. 45-51 ◽  
Author(s):  
FRANCOISE TALBOT ◽  
GEORGES ROBREAU ◽  
FRANCOISE GUEGUEN ◽  
ROGER MALCOSTE
Keyword(s):  
Cell Wall ◽  
Monoclonal Antibodies ◽  
Outer Cell ◽  
Outer Cell Wall

scholarly journals Conidial Hydrophobins of Aspergillus fumigatus

2003 ◽  
Vol 69 (3) ◽  
pp. 1581-1588 ◽  
Author(s):  
Sophie Paris ◽  
Jean-Paul Debeaupuis ◽  
Reto Crameri ◽  
Marilyn Carey ◽  
Franck Charlès ◽  
...  
Keyword(s):  
Cell Wall ◽  
Aspergillus Fumigatus ◽  
Amorphous Layer ◽  
Wall Layer ◽  
Host Cells ◽  
Outer Cell ◽  
Host Immune System ◽  
Wild Type ◽  
Cell Wall Layer ◽  
Outer Cell Wall

ABSTRACT The surface of Aspergillus fumigatus conidia, the first structure recognized by the host immune system, is covered by rodlets. We report that this outer cell wall layer contains two hydrophobins, RodAp and RodBp, which are found as highly insoluble complexes. The RODA gene was previously characterized, and ΔrodA conidia do not display a rodlet layer (N. Thau, M. Monod, B. Crestani, C. Rolland, G. Tronchin, J. P. Latgé, and S. Paris, Infect. Immun. 62:4380-4388, 1994). The RODB gene was cloned and disrupted. RodBp was highly homologous to RodAp and different from DewAp of A. nidulans. ΔrodB conidia had a rodlet layer similar to that of the wild-type conidia. Therefore, unlike RodAp, RodBp is not required for rodlet formation. The surface of ΔrodA conidia is granular; in contrast, an amorphous layer is present at the surface of the conidia of the ΔrodA ΔrodB double mutant. These data show that RodBp plays a role in the structure of the conidial cell wall. Moreover, rodletless mutants are more sensitive to killing by alveolar macrophages, suggesting that RodAp or the rodlet structure is involved in the resistance to host cells.

The effects of chlorpromazine on the outer cell wall of Salmonella typhimurium in ensuring resistance to the drug

2000 ◽  
Vol 14 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Leonard Amaral ◽  
Jette E Kristiansen ◽  
Villy Frølund Thomsen ◽  
Bogooljub Markovich
Keyword(s):  
Cell Wall ◽  
Salmonella Typhimurium ◽  
Outer Cell ◽  
Outer Cell Wall
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