Colonization of Barley Grain by Penicillium verrucosum and Ochratoxin A Formation in the Presence of Competing Fungi

1996 ◽  
Vol 59 (12) ◽  
pp. 1311-1317 ◽  
Author(s):  
NANNAPANENI RAMAKRISHNA ◽  
JOHN LACEY ◽  
JOHN E. SMITH
Keyword(s):  
Electron Microscopy ◽  
Ochratoxin A ◽  
Pure Culture ◽  
Barley Grain ◽  
Enzyme Linked Immunosorbent Assay ◽  
Seed Infection ◽  
Fusarium Sporotrichioides ◽  
Penicillium Verrucosum ◽  
Grain Surface ◽  
Scanning Electron

Colonization of barley grain by Penicillium verrucosum and the formation of ochratoxin A were studied, both in pure culture and when paired with Aspergillus flavus, Fusarium sporotrichioides, and Hyphopichia burtonii, at 20° and 30°C and at 0.97, 0.95 and 0.90 aw over a 3-week period. Grain colonization was assessed on the basis of visible molding, seed infection, and numbers of CFU and by observing hyphal extension on the grain surface by scanning electron microscopy. Ochratoxin A concentrations were assayed by enzyme-linked immunosorbent assay using a monoclonal antibody. Germination of P. verrucosum spores was unaffected by the presence of other species. However, seed infection under most conditions was markedly decreased, relative to pure culture, by the presence of A. flavus and H. burtonii, but only slightly by F. sporotrichioides. The number of CFU of P. verrucosum was only slightly decreased in the presence of other species under most conditions. Generally, production of ochratoxin A by P. verrucosum was inhibited, sometimes significantly, in the presence of A. flavus and H. burtonii, but was changed only slightly by the presence of F. sporotrichioides. There was occasionally temporary enhancement in ochratoxin A production with all species during the 3-week incubation period.

scholarly journals Scanning Electron Microscopy Reveals Different Response Pattern of Four Vitis Genotypes to Xylella fastidiosa Infection

Plant Disease ◽  
2008 ◽  
Vol 92 (2) ◽  
pp. 276-286 ◽  
Author(s):  
Felix B. Fritschi ◽  
Hong Lin ◽  
M. Andrew Walker
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Xylella Fastidiosa ◽  
Systemic Infection ◽  
The Other ◽  
Enzyme Linked Immunosorbent Assay ◽  
Treatment Comparisons ◽  
Different Response ◽  
Scanning Electron ◽  
Tylose Formation

The xylem-limited bacterium Xylella fastidiosa causes Pierce's disease (PD), whose disease symptoms are primarily the result of xylem vessel blockage in susceptible grapevines. Stem internode and petiole tissues from infected and uninfected control plants of four grape genotypes (Vitis vinifera, V. rufotomentosa, V. smalliana, and V. arizonica/candicans) differing in PD susceptibility were examined using scanning electron microscopy (SEM). Tyloses, fibrillar networks, and gum plugs were observed in lumens of tracheary elements in petioles and internodes of both water-inoculated control plants and X. fastidiosa–inoculated plants of all genotypes. Bacteria were not observed in control plants. In both petiole and internode tissues, the greatest number of occluded xylem vessels were observed in V. vinifera and the smallest number in V. arizonica/candicans. The number of xylem vessels infested with X. fastidiosa was greatest in V. vinifera and did not differ among the other three genotypes. Systemic infection was found in all genotypes. The frequency with which X. fastidiosa infested vessels were observed using SEM corresponded well with bacterial levels estimated by enzyme-linked immunosorbent assay. Among infected plants, tylose formation in internodes was lowest in V. arizonica/candicans and did not differ among the other three genotypes. Infection with X. fastidiosa strongly induced tylose formation in V. vinifera and V. smalliana but not in V. arizonica/candicans. Analysis across tissues and genotypes indicated an induction of fibrillar networks and gum occlusions in response to X. fastidiosa infection, whereas treatment comparisons within genotypes were not significant except for V. vinifera petioles. Limiting the spread of X. fastidiosa infection by xylem conduit occlusions does not appear to be the mechanism conferring PD resistance or tolerance to V. arizonica/candicans, V. smalliana, or V. rufotomentosa. In contrast, the strong induction of tyloses may be detrimental rather than beneficial for V. vinifera survival after X. fastidiosa infection.

scholarly journals Pollen grain surface in Vaccinium myrtillus as seen in scanning electron microscopy

2014 ◽  
Vol 50 (4) ◽  
pp. 583-584
Author(s):  
Józef Kocoń ◽  
Kazimierz Pliszka ◽  
Stanisław Muszyński
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Vaccinium Myrtillus ◽  
Grain Surface ◽  
Scanning Electron

Pollen grain surface of <em>Vaccinium myrtillus</em> L. was analyzed by scanning electron microscopy. Pollen grains remain in tetrahedral tetrads. Grain surface is verrucose, consisting of thick, irregularly shaped muri, surrounding small, round or oval lumina. The surface of the muri is fissured, and minute papillae can also be noted.

Monoclonal Antibody-Based Enzyme Linked Immunosorbent Assay of Aflatoxin B1, T-2 Toxin, and Ochratoxin A in Barley

1990 ◽  
Vol 73 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Nannapaneni Ramakrishna ◽  
John Lacey ◽  
Alan A.G Candlish ◽  
John E Smith ◽  
Ian A Goodbrand
Keyword(s):  
Monoclonal Antibodies ◽  
Ochratoxin A ◽  
Aflatoxin B1 ◽  
Chloroform Extract ◽  
Barley Grain ◽  
Competitive Elisa ◽  
Water Soluble ◽  
Enzyme Linked Immunosorbent Assay ◽  
Simple Liquid ◽  
The Mean

Abstract Aflatoxin B1 (B1), T-2 toxin (T2), and ochratoxin A (OA) were assayed in a single extract from barley grain by using competitive enzyme linked immunosorbent assays (ELISAs) with monoclonal antibodies. B1 and T2 monoclonal antibodies were conjugated to horseradish peroxidase for direct competitive ELISA while an indirect competitive ELISA was used for OA determination. The competitive ELISA detected 0.1 ng/mL of B1f 10 ng/mL of T2, or 1 ng/mL of OA. Acetonitrile- 0.5% KCI-6% H2S04 (89 + 10 + 1 ) extracts of barley grain either were diluted 1:10 for direct assay or were subjected to a simple liquid-liquid cleanup procedure to concentrate the extract 10:1 before assay. For cleanup, water was added to the acetonltrile extract to partition water-soluble interfering substances, and then the mycotoxins were re-extracted with chloroform. The chloroform extract was evaporated to dryness and redissolved in Tris HCI buffer for ELISA. The mean recoveries from barley spiked with 4-60 ng/g of B1( 50-5000 ng/g of T2, and 5-500 ng/g of OA were, respectively, 93.8, 80.6, and 95.8%. The mean within-assay, Inter-assay, and subsample coefficients of variation by ELISA of barley grain colonized with toxigenic fungi were &lt;12% for Bi and OA but as high as 17% forT2.

scholarly journals Development of an Alternative Enzyme-assisted Dehairing Method of Animal Skins using Proteases from Bacillus licheniformis MZK05M9

2016 ◽  
pp. 33-37
Author(s):  
Md Arafat Al Mamun ◽  
Md Abir Hosain ◽  
Sobur Ahmed ◽  
Fatema Tuj Zohra ◽  
Rajia Sultana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacillus Licheniformis ◽  
Alkaline Protease ◽  
Room Temperature ◽  
Sodium Sulfide ◽  
Enzyme Preparations ◽  
Goat Skin ◽  
Grain Surface ◽  
Scanning Electron

The present study was aimed to develop an enzyme assisted dehairing method as an alternative and ecofriendly technique to reduce the use of harsh chemicals in leather manufacturing. For this purpose, two proteases namely alkaline protease (601 U/ml) and keratinase (132 U/ml) were produced by Bacillus licheniformis MZK05M9 (BlM9) in Soya molasses medium and Feather mill medium respectively, in 7.0 L bioreactor at pH 7.5 and 37°C. The cell free enzyme preparations were used together at 2.5% level in dehairing experiments. Three sets of experiments for dehairing of goat skins were performed with (1) enzymes; (2) enzymes and 5% lime (CaO) and (3) 2% sodium sulfide (Na2S) and 5% lime. The treatment with enzymes removed 85% of hair from goat skin after 24 hrs under mild shaking condition at room temperature where as the treatment with enzymes and 5% lime together resulted in 100% dehairing under similar conditions. Sodium sulfide along with lime also removed 100% hair faster (with 20 hrs) than other two treatments. The grain surface of the enzyme treated skin was smoother and silkier than that of the chemicals treatment as revealed by Scanning Electron Microscopy. Thus these results indicated that, the enzyme assisted method can be applied in largescale dehairing trial to reduce the use of harsh sodium sulfide.Bangladesh J Microbiol, Volume 32, Number 1-2,June-Dec 2015, pp 33-37

scholarly journals The ultrastructure of pollen grain surface in allotetraploid petunia (Petunia hybrida hort. superbissima) as revealed by scanning electron microscopy

2015 ◽  
Vol 46 (4) ◽  
pp. 599-601
Author(s):  
S. Muszyński ◽  
J. Kocoń ◽  
W. Guzowski ◽  
M. Bieguński
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Petunia Hybrida ◽  
Pollen Grain ◽  
Characteristic Pattern ◽  
Grain Surface ◽  
Pollen Grain Wall ◽  
Scanning Electron

The ultrastructure of pollen grain surface in allotetraploid petunias was analyzed by scanning electron microscopy. The pollen grain wall is developed into characteristic pattern of convulations.

Assessment of Thrombotic Risk in Atrial Fibrillation with Ultrasound Molecular Imaging of P-Selectin

2018 ◽  
Vol 118 (02) ◽  
pp. 388-400 ◽  
Author(s):  
Yuanwen Jing ◽  
Yinlan Hu ◽  
Hairui Li ◽  
Junfen Wang ◽  
Xiaoyun Si ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Atrial Fibrillation ◽  
Risk Assessment ◽  
Molecular Imaging ◽  
Left Atrial ◽  
Enzyme Linked Immunosorbent Assay ◽  
Atrial Pacing ◽  
Thrombotic Risk ◽  
Ultrasound Molecular Imaging ◽  
Scanning Electron

AbstractMolecular imaging of inflammatory mediators in atria may contribute to thrombotic risk assessment of atrial fibrillation (AF). We investigated the feasibility of ultrasound molecular imaging (UMI) targeted to P-selectin to assess thrombotic risk in AF. Rat AF models were established with rapid atrial pacing. Microbubbles targeted to P-selectin were injected into the rats, followed by left atrial (LA) UMI examination. Furthermore, P-selectin, platelets (PLTs), fibrin and tissue factor (TF) of LA were detected by histopathology and scanning electron microscopy. Plasma levels of P-selectin, thrombin-antithrombin complex (TAT) and prothrombin fragment 1 + 2 (F1 + 2) were measured by enzyme-linked immunosorbent assay. The data showed that P-selectin in LA was correlated with PLT, fibrin and TF (r = 0.735, p < 0.05; r = 0.827, p < 0.05; r = 0.785, p < 0.05, respectively). The plasma level of P-selectin was correlated with the expression of TAT and F1 + 2 (r = 0.866, p < 0.05; r = 0.916, p < 0.05, respectively). The contrast video intensity of adhered microbubbles targeted to P-selectin was correlated with the levels of P-selectin, PLT and fibrin in LA (r = 0.768, p < 0.05; r = 0.798, p < 0.05; r = 0.745, p < 0.05, respectively). In conclusion, P-selectin may serve as a biomarker for thrombotic risk in AF and can be quantified by UMI to assess thrombotic risk.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

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