scholarly journals Alterations in Mycelial Morphology and Flow Cytometry Assessment of Membrane Integrity of Ganoderma boninense Stressed by Phenolic Compounds

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 930
Author(s):  
Daarshini Ganapathy ◽  
Yasmeen Siddiqui ◽  
Khairulmazmi Ahmad ◽  
Fariz Adzmi ◽  
Kong Lih Ling
Keyword(s):  
Electron Microscopy ◽  
Phenolic Compounds ◽  
Membrane Integrity ◽  
Cell Integrity ◽  
Ganoderma Boninense ◽  
Fungal Cell ◽  
Antifungal Effect ◽  
Basal Stem Rot ◽  
Transmission Electron ◽  
Global Increase

Global increase in demand for palm oil has caused an intensification in oil palm plantation; however, production is greatly hindered by Basal Stem Rot (BSR) disease caused by Ganoderma boninense. There are many approaches to controlling BSR, although, there is no accurate, sustainable and effective method to suppress G. boninense completely. Hence, four phenolic compounds [Gallic acid (GA), Thymol (THY), Propolis (PRO) and Carvacrol (CARV)] were selected to evaluate their antifungal effect, ability to alter the mycelium morphology, and fungal cell integrity against G. boninense. Significant differences (p < 0.05) were observed and 94% of inhibition was exerted by GA on G. boninense growth. Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy observations revealed that GA and THY treatment caused severe damage to the mycelium and recorded the highest amount of sugar and electrolyte leakage. The study of cell integrity and morphological disruption has elucidated the reduction of G. boninense cell viability. Generally, our findings confirm the fungistatic effects of GA and THY. The evolution of phenolic compounds during the phytopathology studies indicated their coherence in eradicating the G. boninense. It is proposed that GA and THY had the potential to be developed further as a natural antifungal treatment to suppress G. boninense.

scholarly journals DISTRIBUTION OF PHENOLIC COMPOUNDS, PECTINS AND HEMICELLULOSES IN MATURE PIT MEMBRANES AND ITS VARIATION BETWEEN PIT TYPES IN ENGLISH OAK XYLEM (QUERCUS ROBUR)

IAWA Journal ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 402-419
Author(s):  
Jong Sik Kim ◽  
Geoffrey Daniel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phenolic Compounds ◽  
Quercus Robur ◽  
Transmission Electron ◽  
Pit Membrane ◽  
Bordered Pits ◽  
English Oak ◽  
Pectin Epitopes

Although there is considerable information on the chemistry of bordered intervessel pit membranes, little is known on the pit membrane chemistry of other pit types in hardwoods. This study investigated distribution of phenolic compounds, pectins and hemicelluloses in different mature pit membranes of English oak xylem using transmission electron microscopy coupled with cytochemistry and immunocytochemistry. Mature bordered intertracheid (vasicentric)- and tracheid-vessel pits showed presence of xyloglucan and heteromannan (hemicelluloses) epitopes across the pit membrane (except for the annulus regions) with differences in amounts of epitopes between earlywood (EW) and latewood (LW). In contrast, pectin epitopes were detected only in the annulus regions of pit membranes. Unlike bordered pits, half-bordered (tracheary-parenchyma pits) and simple (parenchyma pits) pit membranes were rich in pectin epitopes but lacked heteromannan epitopes, indicating difference in pit membrane chemistry between pit types. Distribution of phenolic compounds also differed between pit types and between EW and LW. LW also showed great variations in distribution of phenolic compounds between vessels. Together, this study demonstrates that there are great variations in pit membrane chemistry between pit types and between EW and LW in English oak xylem.

scholarly journals Structure-Function Relationship of Antibacterial Synthetic Peptides Homologous to a Helical Surface Region on Human Lactoferrin against Escherichia coli Serotype O111

1998 ◽  
Vol 66 (6) ◽  
pp. 2434-2440 ◽  
Author(s):  
Daniel S. Chapple ◽  
David J. Mason ◽  
Christopher L. Joannou ◽  
Edward W. Odell ◽  
Vanya Gant ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Transmission Electron Microscopy ◽  
Flow Cytometry ◽  
Antibacterial Activity ◽  
Synthetic Peptides ◽  
Membrane Integrity ◽  
E Coli ◽  
Transmission Electron ◽  
Helical Region

ABSTRACT Lactoferricin includes an 11-amino-acid amphipathic alpha-helical region which is exhibited on the outer surface of the amino-terminal lobe of lactoferrin. Synthetic peptides homologous to this region exhibited potent antibacterial activity against a selected range of both gram-negative and gram-positive bacteria. An analog synthesized with methionine substituted for proline at position 26, which is predicted to disrupt the helical region, abolished antibacterial activity against Escherichia coli and considerably reduced antibacterial activity against Staphylococcus aureus and anAcinetobacter strain. The mode of action of human lactoferrin peptide (HLP) 2 against E. coli serotype O111 (NCTC 8007) was established by using flow cytometry, surface plasmon resonance, and transmission electron microscopy. Flow cytometry was used to monitor membrane potential, membrane integrity, and metabolic processes by using the fluorescent probes bis-1,3-(dibutylbarbituric acid)-trimethine oxonol, propidium iodide, and carbonyl cyanide m-chlorophenylhydrazone, respectively. HLP 2 was found to act at the cell membrane, causing complete loss of membrane potential after 10 min and of membrane integrity within 30 min, with irreversible damage to the cell as shown by rapid loss of viability. The number of particles, measured by light scatter on the flow cytometer, dropped significantly, showing that bacterial lysis resulted. The peptide was shown to bind toE. coli O111 lipopolysaccharide by using surface plasmon resonance. Transmission electron microscopy revealed bacterial distortion, with the outer membrane becoming detached from the inner cytoplasmic membrane. We conclude that HLP 2 causes membrane disruption of the outer membrane, resulting in lysis, and that structural considerations are important for antibacterial activity.

scholarly journals Morphological Effect of the New Antifungal Agent ME1111 on Hyphal Growth of Trichophyton mentagrophytes, Determined by Scanning and Transmission Electron Microscopy

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Yayoi Nishiyama ◽  
Sho Takahata ◽  
Shigeru Abe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Antifungal Agent ◽  
Structural Changes ◽  
Hyphal Growth ◽  
Trichophyton Mentagrophytes ◽  
Fungal Cell ◽  
Morphological Effect ◽  
Content Type ◽  
Transmission Electron

ABSTRACT The effects of ME1111, a novel antifungal agent, on the hyphal morphology and ultrastructure of Trichophyton mentagrophytes were investigated by using scanning and transmission electron microscopy. Structural changes, such as pit formation and/or depression of the cell surface, and degeneration of intracellular organelles and plasmolysis were observed after treatment with ME1111. Our results suggest that the inhibition of energy production by ME1111 affects the integrity and function of cellular membranes, leading to fungal cell death.

scholarly journals Ultrastructure and nanomorphology of the American mink (mustela vison) kidney

2019 ◽  
Vol 485 (5) ◽  
pp. 642-645
Author(s):  
V. O. Ezhkov ◽  
M. S. Ezhkova ◽  
I. A. Yapparov ◽  
A. Kh. Yapparov ◽  
I. R. Nizameev ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
American Mink ◽  
Membrane Integrity ◽  
Morphological Parameters ◽  
Subcellular Organelles ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Microscopy Images

The ultrastructure of the nephron subcellular organelles was studied in healthy mink kidneys. The data obtained were compared with the results of transmission electron microscopy. The renal cell nanomorphology proved to be similar when electronograms and the atomic force microscopy images were analyzed. The methods used enabled us to visualize the glomerular capillary endotheliocytes with cytolemma pits in the area of fenestrae that provide blood filtration; in the proximal nephron part, on the apical pole of the epithelial cells, brush-border soft microvilli were observed. The microvilli were characterized by a well-organized structure along their entire length and the membrane integrity. The data obtained show morphological parameters of the healthy mink organ and can be helpful in diagnosing of nephropathology.

scholarly journals Fungal Cell Wall Septation and Cytokinesis Are Inhibited by Bleomycins

2003 ◽  
Vol 47 (10) ◽  
pp. 3281-3289 ◽  
Author(s):  
Carol W. Moore ◽  
Judith McKoy ◽  
Robert Del Valle ◽  
Donald Armstrong ◽  
Edward M. Bernard ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Division ◽  
Cell Walls ◽  
Intact Cell ◽  
Fungal Growth ◽  
Fungal Cell ◽  
Transmission Electron ◽  
Mother And Daughter ◽  
Fungal Organisms

ABSTRACT When the essential and distinctive cell walls of either pathogenic or nonpathogenic fungi break, cytoplasmic membranes rupture and fungi die. This fungicidal activity was discovered previously on nonproliferating Saccharomyces cerevisiae cells treated briefly with the oxidative tool and anticancer drug family of bleomycins. The present studies investigated effects of bleomycin on growing fungal organisms. These included the medically important Aspergillus fumigatus and Cryptococcus neoformans, as well as the emerging human pathogen and fungal model, S. cerevisiae. Bleomycin had its highest potency against A. fumigatus. Scanning electron microscopy and thin-section transmission electron microscopy were used to study morphological growth characteristics. Killing and growth inhibition were also measured. Long, thin, and segmented hyphae were observed when A. fumigatus was grown without bleomycin but were never observed when the mold was grown with the drug. Bleomycin arrested conidial germination, hyphal development, and the progression and completion of cell wall septation. Similarly, the drug inhibited the construction of yeast cell wall septa, preventing cytokinesis and progression in the cell division cycle of S. cerevisiae. Even when cytoplasms of mother and daughter cells separated, septation and cell division did not necessarily occur. Bizarre cell configurations, abnormally thickened cell walls at mother-daughter necks, abnormal polarized growth, large undivided cells, fragmented cells, and empty cell ghosts were also produced. This is the first report of a fungicidal agent that arrests fungal growth and development, septum formation, and cytokinesis and that also preferentially localizes to cell walls and alters isolated cell walls as well as intact cell walls on nongrowing cells.

Glandular trichome diversity on leaves ofLippia origanoidesandLippia stachyoides(Verbenaceae): morphology, histochemistry, and ultrastructure

Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 297-306 ◽  
Author(s):  
Luiz Ricardo dos Santos Tozin ◽  
Shelly Favorito Carvalho ◽  
Silvia Rodrigues Machado ◽  
Tatiane Maria Rodrigues
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phenolic Compounds ◽  
Glandular Trichomes ◽  
Chemical Compounds ◽  
Glandular Trichome ◽  
Transmission Electron ◽  
Conventional Methods ◽  
Subcellular Level

Despite the ecological and medicinal importance of glandular trichomes in Verbenaceae, information on their structure, mainly at the subcellular level, is sparse. We analyzed the morphology and histochemistry of glandular trichomes in Lippia origanoides Kunth and Lippia stachyoides Cham., using conventional methods in anatomy, histochemistry, scanning and transmission electron microscopy, and ultracytochemical techniques. Five morphotypes (I–V) of glandular trichomes were identified in L. origanoides, and four morphotypes (I, III–V) in L. stachyoides. Morphotype I is the most abundant in both species. Lipids were detected in all morphotypes except IV; terpenes in I, II, and V; phenolic compounds in all morphotypes except V; neutral polysaccharides and protein in all morphotypes; mucilage exclusively in IV; alkaloids only in III. Each glandular morphotype showed ultrastructural peculiarities compatible with the chemical compounds produced. An association between glandular morphotype, secretion composition, and ultrastructural features in Lippia species was revealed, suggesting functions specific to each glandular morphotype.

scholarly journals 258ULTRASTRUCTURAL STUDY OF STALLION SPERM FOLLOWING THAWING, CAPACITATING AND IVF PROCEDURES: EFFECT OF THE PRESENCE OF CUMULUS-ENCLOSED OOCYTES

2004 ◽  
Vol 16 (2) ◽  
pp. 249
Author(s):  
F. Abbate ◽  
P.G. Germanà ◽  
S. Colleoni ◽  
F. Gandolfi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Developmental Competence ◽  
Lower Percentage ◽  
Sperm Cells ◽  
Transmission Electron ◽  
Intact Membrane

The use of IVF in horses has a limited efficiency, reflecting low oocyte developmental competence and inadequate sperm capacitation procedures. In a preliminary study, using carboxyfluorescein diacetate/propidium iodide staining, we determined that the freezing-thawing procedure left only 56.6±3.4 % of the sperm cells with an intact membrane. The following incubation in TALP-IVF induced membrane damage at high rates with only 9.58±1.8 % of them intact after 18h. However, the presence of at least four cumulus-enclosed oocytes (CEO) in the medium significantly increased the number of membrane-intact spermatozoa at the end of incubation (53.87±1.99%). This indicated that the sperm thawing and capacitating procedures can damage the cell membrane but the presence of four or more CEO in TALP-IVF could prevent further damages. The aim of the study was to investigate in detail the membrane damages and to analyze the differences induced by the presence of CEO. Spermatozoa were thawed in water at 37°C, and centrifuged for 30 minutes at 600g in a 45–90% Percoll gradient made with modified Tyrode’s medium. The sperm pellet was washed once in the same medium and diluted to a final concentration of 1×106 spermatozoa/ml TALP supplemented with 0.6% (w/v) BSA fatty acid free and 12μgmL−1 heparin (TALP-IVF). Sperm cells were incubated with 0 or 4 in vitro-matured CEO. Sperm cells were examined after thawing, 0, 2 and 18h from the beginning of incubation in TALP-IVF. Each experiment was replicated at least 3 times. Both scanning and transmission electron microscopy were performed on sperm samples fixed in 2.5% glutaraldehyde in 0.1M phosphate buffer, pH 7.2, using standard procedures. Specimens for scanning electron microscopy were examined under a field emission gun JEOL JSM 6301 microscope. For transmission electron microscopy the samples were examined with a JEOL JEM 100 SX. A minimum of 25 cells were analyzed for each group. Immediately after thawing, damaged spermatozoa showed, on the surface of their heads, small vesicles correlated to a progressive process of vacuolisation and degeneration of membrane integrity. The same lesions were visible at all the successive time points taken into account. Moreover, a loss of the acrosome integrity with acrosomal swelling and a decrease of content homogeneity were observed particularly in the spermatozoa cultured for 18 h without CEO. When CEO were present in the IVF medium lesions were visible in a lower percentage of spermatozoa but the type of lesions did not differ from those observed in their absence. These observations confirmed our previous data and gave more details on the lesions that occur during the IVF procedures in the horse. Supported by MURST COFIN grant n. 2001078849.

scholarly journals Antifungal Action of Methylene Blue Involves Mitochondrial Dysfunction and Disruption of Redox and Membrane Homeostasis in C. albicans

2016 ◽  
Vol 10 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Moiz A. Ansari ◽  
Zeeshan Fatima ◽  
Saif Hameed
Keyword(s):  
Methylene Blue ◽  
Mitochondrial Dysfunction ◽  
Membrane Integrity ◽  
Redox Status ◽  
Antifungal Effect ◽  
Transmission Electron ◽  
Drug Efflux Pumps ◽  
Antifungal Action ◽  
Compositional Changes ◽  
Major Drug

Candida albicansis known to cause infections ranging from superficial and systemic in immunocompromised person. In this study, we explored that the antifungal action of Methylene blue (MB) is mediated through mitochondrial dysfunction and disruption of redox and membrane homeostasis againstC. albicans. We demonstrated that MB displayed its antifungal potential againstC. albicansand two clinical isolates tested. We also showed that MB is effective against two non-albicansspecies as well. Notably, the antifungal effect of MB seems to be independent of the major drug efflux pumps transporter activity. We explored that MB treatedCandidacells were sensitive on non-fermentable carbon source leading us to propose that MB inhibits mitochondria. This sensitive phenotype was reinforced with the fact that sensitivity ofCandidacells to MB could be rescued upon the supplementation of ascorbic acid, an antioxidant. This clearly suggests that disturbances in redox status are linked with MB action. We further demonstrated thatCandidacells were susceptible to membrane perturbing agentviz. SDS which was additionally confirmed by transmission electron micrographs showing disruption of membrane integrity. Moreover, the ergosterol levels were significantly decreased by 66% suggesting lipid compositional changes due to MB. Furthermore, we could demonstrate that MB inhibits the yeast to hyphal transition inC. albicanswhich is one of the major virulence attribute in most of the hyphal inducing conditions. Taken together, the data generated from present study clearly establishes MB as promising antifungal agent that could be efficiently employed in strategies to treatCandidainfections.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

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