Bacteriocin-like substance inhibits potato soft rot caused by Erwinia carotovora

2006 ◽  
Vol 52 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Florencia Cladera-Olivera ◽  
Geruza R Caron ◽  
Amanda S Motta ◽  
André A Souto ◽  
Adriano Brandelli
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Bacillus Licheniformis ◽  
Membrane Lipids ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
Bactericidal Effect ◽  
Potato Tubers ◽  
Transmission Electron ◽  
Bacterial Surfaces

Soft rot is a major problem encountered in potatoes during postharvest storage. The soft rot bacterium Erwinia carotovora was inhibited by a novel bacteriocin-like substance (BLS) produced by Bacillus licheniformis P40. The BLS caused a bactericidal effect on E. carotovora cells at 30 µg mL–1. Transmission electron microscopy showed that BLS-treated cells presented wrinkled bacterial surfaces and shrinkage of the whole cell, indicating plasmolysis. Erwinia carotovora cells treated with BLS were analyzed by FTIR showing differences in the 1390 cm–1 and 1250–1220 cm–1 bands, corresponding to assignments of membrane lipids. BLS was effective in preventing E. carotovora spoilage on potato tubers, reducing the symptoms of soft rot at 240 µg mL–1 and higher concentrations. Soft rot development was completely blocked at 3.7 mg mL–1. This BLS showed potential to protect potato tubers during storage. Key words: bacteriocin, plant pathogen, potato, soft rot, storage.

scholarly journals Resistance of the S1 layer in kempas heartwood fibers to soft rot decay

IAWA Journal ◽  
2018 ◽  
Vol 39 (1) ◽  
pp. 37-42
Author(s):  
Adya P. Singh ◽  
Andrew H.H. Wong ◽  
Yoon Soo Kim ◽  
Seung Gon Wi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Middle Lamella ◽  
Wood Decay ◽  
Soft Rot ◽  
Normal Wood ◽  
Fibre Cell ◽  
Utility Pole ◽  
Transmission Electron

Naturally durable heartwoods, where available, continue to be used as support structures in environments considered hazardous, particularly in ground contact. However, durability of heartwoods against wood decay microorganisms varies. Therefore, it is important to evaluate heartwood products for their in-service performance in order to maximise benefits derived from this valuable natural resource of limited supply. In the work presented, wood pieces from a kempas (Koompassia malaccensis) utility pole that had been placed in service in an acidic soil in Malaysia, and in time had softened at the ground-line position, were examined by light and transmission electron microscopy to evaluate the cause of deterioration.Light microscopy (LM) provided evidence of extensive attack on fibre cell walls by cavity-producing soft rot fungi. Transmission electron microscopy (TEM) revealed in greater detail the distribution and micromorphologies of cavities as well as their relationships to the fine structure of fibre cell walls, which consisted of a highly electron dense middle lamella, a moderately dense S1 layer and a multilamellar S2 layer with variable densities, reflecting differences in lignin concentration. The resistance of the moderately dense S1 layer to soft rot was a feature of particular interest and is the main focus of the work presented. The resistance appeared to be correlated with high lignification of the outermost region of the S2 wall, interfacing with the S1 layer, an unusual cell wall feature not previously described for normal wood.

Wound healing in whole potato tubers: a cytochemical, fluorescence, and ultrastructural analysis of cut and bruise wounds

1995 ◽  
Vol 73 (9) ◽  
pp. 1436-1450 ◽  
Author(s):  
Norman Thomson ◽  
Ray F. Evert ◽  
Arthur Kelman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Wound Healing ◽  
Healing Process ◽  
Potato Tubers ◽  
Bright Field ◽  
Wound Site ◽  
Transmission Electron ◽  
Suberin Lamellae ◽  
Wound Reaction

Healing was investigated in whole tubers wounded by cuts and bruises and compared with core, disc, and slice wounds. Bright-field, fluorescence, and transmission electron microscopy were used in conjunction with cytochemical analyses. Wound reaction cells bordering a wound site responded to wounding initially with deposition of callose at the primary pit fields followed by intussusception of lignin in the middle lamellae and primary walls and suberization along the inner surfaces of the primary walls. Suberization was initially detected by the presence of a prosuberin lamella in which suberin lamellae subsequently developed. Both lignin and the prosuberin lamella were first detected in wound reaction cells of the cortex at 4 h in cut, core, disc, and slice wounds and at 8 h in bruise wounds. Healing was completed with formation of a continuous wound cork cambium beneath the wound site. With lignification and suberization, wounded potato tubers apparently develop specialized barriers against potential pathogens and water loss. The overall healing process proceeds more slowly in bruise wounds than in cut wounds. Moreover, the capacity for wound healing decreases with increasing age of the tuber, or time in storage. Key words: lignin, prosuberin lamella, Solanum tuberosum, suberin, suberization, wound healing.

Microbial Degradation of Cca-Treated Cooling Tower Timbers

IAWA Journal ◽  
1992 ◽  
Vol 13 (2) ◽  
pp. 215-231 ◽  
Author(s):  
A.P. Singh ◽  
M.E. Hedley ◽  
D.R. Page ◽  
C.S. Han ◽  
K. Atisongkroh
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Pinus Radiata ◽  
Microbial Degradation ◽  
Cooling Tower ◽  
Soft Rot ◽  
Industrial Water ◽  
Water Cooling ◽  
Transmission Electron ◽  
Microbial Damage

Transmission electron microscopy of decaying CCA-treated Pinus radiata timbers from an industrial water cooling tower showed the presence of a thick biofilm covering some areas of the wood. The biofilm contained various morphologically distinct forms of microorganisms embedded in a slime. The study provided evidence of the activity of soft rot fungi and tunnelling and erosion bacteria in wood cells covered by the biofilm. The extent of microbial damage to wood cells varied, with combined fungal and bacterial attack having the most damaging impact.

Electron microscopic and chemical study of degraded Pinus radiata wood from a marine pile

1991 ◽  
Vol 69 (12) ◽  
pp. 2762-2771 ◽  
Author(s):  
A. P. Singh ◽  
M. E. Hedley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Analysis ◽  
Light Microscopy ◽  
Pinus Radiata ◽  
Cellulose Degradation ◽  
Middle Lamella ◽  
Soft Rot ◽  
Minor Role ◽  
Transmission Electron

During an inspection of marine piles, 12 years after installation, severe degradation was noted on one of them in the vicinity of a corroded eyebolt. The wood was dark brown in colour and tended to crumble easily. Wood fragments were examined by light microscopy and scanning and transmission electron microscopy and were also analyzed for carbohydrates and lignin. Light microscopy indicated numerous cracks in tracheid walls resulting in delamination at the middle lamella – S1 and S1–S2 boundaries and also in fractures across the tracheid wall. Chemical analysis showed extensive loss of both hemicellulose and cellulose. Observations with polarized light microscopy supported the data from chemical analysis on cellulose degradation, indicating a loss of crystallinity. Although presence of microbial flora in the lumen of wood cells was revealed by scanning electron microscopy, transmission electron microscopy showed only occasional soft rot decay zones in the S2 layer. The degradation of Pinus radiata wood from this sample appears to have been caused primarily by brown rot attack and (or) iron corrosion products, soft rot attack playing a minor role. Key words: Pinus radiata wood, marine pile, wood cell wall degradation, electron microscopy.

The Study of Structure and Energy Domain of ZiJin Stone

2013 ◽  
Vol 753-755 ◽  
pp. 85-87
Author(s):  
Qi Shan Li ◽  
Ming Cheng Liu ◽  
Qi Long Jiang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Bactericidal Effect ◽  
Micro Structure ◽  
Transmission Electron ◽  
Energy Domain ◽  
Micro Structures ◽  
Scanning Electron

It is mainly addressed the relation between the structure and the energy domain using scanning electron microscope (SEM), transmission electron microscopy (TEM) to observe the micro structure. It indicates that some specific micro structures exiting in the Zijin Stone, such as the nanocrystal structure, nanofiber structure, and nanolayer structure, by which the capacities of releasing anion, bactericidal effect can to some extent be explained.

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.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Comparative Microstructures of Ion Milled and Electrochemically Thinned Composite Materials

1974 ◽  
Vol 32 ◽  
pp. 546-547
Author(s):  
R.R. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Composite Materials ◽  
Great Difficulty ◽  
Ion Milling ◽  
Transmission Electron ◽  
Ion Damage ◽  
Intermetallic Composite

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.

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