Ultrastructure of commercial recycled pulp fibers for the production of packaging paper

Holzforschung ◽  
2005 ◽  
Vol 59 (6) ◽  
pp. 675-680 ◽  
Author(s):  
Jonas Brändström ◽  
Jean-Paul Joseleau ◽  
Alain Cochaux ◽  
Nathalie Giraud-Telme ◽  
Katia Ruel
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Significant Proportion ◽  
Pulp Fibers ◽  
Chemical Pulp ◽  
Recycled Pulp ◽  
Transmission Electron ◽  
Large Heterogeneity ◽  
Recycled Fibers ◽  
Packaging Paper

Abstract Transmission electron microscopy was used to investigate the ultrastructure of recycled pulp fibers originating from a household collection plant and intended for the production of packaging paper. Three recovered paper grades and recycling processes, including pulping, screening, cleaning and refining, were assessed with emphasis on surface and internal fibrillation as well as xylan localization. Results showed a large heterogeneity with respect to fiber ultrastructure within and between the grades. Screening and cleaning steps had no detectable effects, but refining clearly increased cell-wall delamination and surface fibrillation. Immunolabeling of xylans showed that they were distributed rather evenly across the cell walls. They were also present on fines. Two different mechanisms for fiber delamination and surface fibrillation were found, one which implies that internal and external fibrillation take place simultaneously across the cell wall, and another which implies successive peeling of layers or sub-layers from the outside towards the inside. It is suggested that recycled fibers of chemical pulp origin undergo the former mechanism and recycled fibers that contain lignin binding the cell wall matrix give rise to the latter peeling mechanism. Because several recycled fibers were severely delaminated and almost fractured, we suggest that to produce a good packaging paper, it is important that recycled pulp should contain a significant proportion of fibers with high intrinsic strength.

scholarly journals Differences in cell wall of thin and thick filaments of cyanobacterium Aphanizomenon gracile SAG 31.79 and their implications for different resistance to Daphnia grazing

2016 ◽  
Author(s):  
Lukasz Wejnerowski ◽  
Slawek Cerbin ◽  
Maria K. Wojciechowicz ◽  
Marcin K. Dziuba
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Walls ◽  
Cell Wall Thickness ◽  
Filamentous Cyanobacterium ◽  
Thin Sections ◽  
Thick Filaments ◽  
Transmission Electron ◽  
The Difference ◽  
Aphanizomenon Gracile

<p>Recent studies have shown that the filamentous cyanobacterium <em>Aphanizomenon gracile</em> Lemmermann, strain SAG 31.79, consists of two types of filaments that differ in thickness. These two types are known to vary in resistance to <em>Daphnia</em> <em>magna</em> grazing: thin filaments (&lt;2.5 µm) are more vulnerable to grazing than the thick ones (&gt;2.5 µm). In this study, we investigated whether the difference in the vulnerability to grazing of thin and thick filaments is a result of different thickness of their cell walls, a filament stiffness determinant. We expected thick filaments to have thicker cell walls than the thin ones. Additionally, we analysed whether cell wall thickness correlates with filament thickness regardless of the filament type. A morphometric analysis of cell walls was performed using transmission electron micrographs of ultra-thin sections of the batch-cultured cyanobacterial material.  Our study revealed that the thin type of filaments had thinner cell walls than the thick filaments. Moreover, cell wall thickness was positively correlated with filament thickness. TEM (transmission electron microscopy) observations also revealed that the thin type of filaments was often at different stages of autocatalytic cell destruction, which was mainly manifested in the increase in cell vacuolization and degradation of the cytoplasm content. Based on our findings, we assume that previously reported higher resistance of thick filaments to <em>Daphnia</em> grazing results from greater stiffness and excellent physiological conditions of thick filaments. </p>

Electron Energy Loss Spectroscopy (EELS) for Quantification of Cell-Wall Penetration of a Melamine Resin

Holzforschung ◽  
1999 ◽  
Vol 53 (2) ◽  
pp. 111-117 ◽  
Author(s):  
A.O. Rapp ◽  
H. Bestgen ◽  
W. Adam ◽  
R.-D. Peek
Keyword(s):  
Cell Wall ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Cell Walls ◽  
Literature Survey ◽  
Melamine Resin ◽  
Transmission Electron ◽  
Synthetic Resins ◽  
Electron Energy Loss

Summary A literature survey was performed to find progress in techniques for monitoring penetration of synthetic resins in wood cell walls. Electron energy loss spectroscopy (EELS) in combination with transmission electron microscopy (TEM) was successfully applied for the high resolution examination of the distribution of a partly methylated hydroxymethyl melamine resin in Norway spruce (Picea abies Karst.) earlywood cell walls. The nitrogen of the resin was found as clearly detectable signals in all layers of the lignified cell wall, thus allowing the quantification of resin which had penetrated into the different layers. Possible principles of decay protection of wood which has been upgraded with low concentrated aqueous solutions of modified hydroxymethyl melamine resins with medium to low hydroxymethyl/melamine ratios are discussed.

Ultrastructure of hyperparasitism of Coniothyrium minitans on sclerotia of Sclerotinia sclerotiorum

1987 ◽  
Vol 65 (12) ◽  
pp. 2483-2489 ◽  
Author(s):  
H. C. Huang ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Sclerotinia Sclerotiorum ◽  
Cell Walls ◽  
Chemical Activity ◽  
Coniothyrium Minitans ◽  
Medullary Tissue ◽  
Transmission Electron

Transmission electron microscopy revealed that hyphae of the hyperparasite Coniothyrium minitans invade sclerotia of Sclerotinia sclerotiorum, resulting in the destruction and disintegration of the sclerotium tissues. The dark-pigmented rind tissue is more resistant to invasion by the hyperparasite than the unpigmented cortical and medullary tissues. Evidence from cell wall etching at the penetration site suggests that chemical activity is required for hyphae of C. minitans to penetrate the thick, melanized rind walls. The medullary tissue infected by C. minitans shows signs of plasmolysis, aggregation, and vacuolization of cytoplasm and dissolution of the cell walls. While most of the hyphal cells of C. minitans in the infected sclerotium tissue are normal, some younger hyphal cells in the rind tissue were lysed and devoid of normal contents.

Cellular Characteristics of Dinitroaniline Herbicide-Resistant Goosegrass (Eleusine indica)

Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Bernal E. Valverde ◽  
Arnold P. Appleby ◽  
Steven R. Radosevich ◽  
Alfred Soeldner
Keyword(s):  
North Carolina ◽  
Cell Wall ◽  
South Carolina ◽  
Cell Walls ◽  
Primary Root ◽  
Wall Material ◽  
Root Cells ◽  
Eleusine Indica ◽  
Herbicide Resistant ◽  
Transmission Electron

Primary root cells from five dinitroaniline-resistant (R) and three susceptible (S) goosegrass biotypes from North Carolina and South Carolina were observed by transmission electron microscopy to determine whether resistance was associated with changes in cell wall formation. Cell wall malformations were found in some cells from two of the R-biotypes and in one of the S-biotypes. Malformations consisted of partially deposited cell walls and the inclusion of cell wall material in the cytoplasm. Some of the affected cells also had abnormal, lobed nuclei and malformed mitochondria. There seems to be little or no correlation between dinitroaniline resistance and cell wall malformations.

Action of Xylanases on Chemical Pulp Fibers Part I : Investigations Gn Cell-Wall Modifications

1986 ◽  
Vol 6 (2) ◽  
pp. 147-165 ◽  
Author(s):  
F. Mora ◽  
J. Cotrtat ◽  
F. Barnoud ◽  
F. Pla ◽  
P. Nee
Keyword(s):  
Cell Wall ◽  
Pulp Fibers ◽  
Chemical Pulp

Ultrastructure of conidiogenesis and appendage ontogeny in the coelomycete Bartalinia robillardoides

2003 ◽  
Vol 81 (11) ◽  
pp. 1083-1090 ◽  
Author(s):  
M KM Wong ◽  
E BG Jones ◽  
M A Abdel-Wahab ◽  
D WT Au ◽  
L LP Vrijmoed
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Cell Walls ◽  
Apical Cell ◽  
Conidiogenous Cell ◽  
Dense Layer ◽  
Basal Cells ◽  
Outer Electron ◽  
Transmission Electron ◽  
Scanning Electron

Conidiogenesis and conidial appendage ontogeny of the coelomycete Bartalinia robillardoides Tassi was studied at the light microscope, scanning electron microscope, and transmission electron microscope levels. Conidiogenesis in B. robillardoides is holoblastic. Appendage ontogeny begins as a cellular outgrowth of the apical and the basal cells of the young conidium, the former developing prior to the basal appendage. Conidia detach from the conidiogenous cells schizolytically. Mature conidial cell walls comprise two layers: an outer electron-dense layer, 30–38 nm, and an inner less electron-dense layer, 100–125 nm. The apical appendages arise from an outgrowth of the apical cell, which then branches to form the appendages. The single basal appendage arises from the junction between the basal cell of the conidium and the conidiogenous cell prior to conidial detachment from the conidiogenous cell, as an outgrowth of the conidial cell wall. Conidial appendage ontogeny is compared with those of other coelomycetes.Key words: Annellidic, appendage ontogeny, coelomycetes, holoblastic.

Weight Loss and Cell Wall Degradation in Rubberwood Caused by Sapstain Fungus Botryodiplodia theobromae

Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 225-228 ◽  
Author(s):  
E. J. M. Florence ◽  
R. Gnanaharan ◽  
P. Adya Singh ◽  
J. K. Sharma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Weight Loss ◽  
Cell Wall ◽  
Cell Walls ◽  
Cell Wall Degradation ◽  
Botryodiplodia Theobromae ◽  
Percent Weight Loss ◽  
Transmission Electron

Summary Botryodiplodia theobromae is the predominant fungus causing sapstain in rubberwood in Kerala, India. The fungus causes up to 12.2 percent weight loss in rubberwood over a period of sixteen weeks. Transmission Electron Microscopy (TEM) of sapstained rubberwood provided evidence on hyphal invasion of cells by B. theobromae through the pit region, facilitated by its ability to degrade pit membranes. The study also revealed that B. theobromae caused degradation of lignified cell walls by erosion of the cell wall surfaces of wood elements.

Cell wall differentiation during early somatic embryogenesis in plants. II. Ultrastructural study and pectin immunolocalization on chicory embryos

2000 ◽  
Vol 78 (6) ◽  
pp. 824-831 ◽  
Author(s):  
Audrey Chapman ◽  
Anne-Sophie Blervacq ◽  
Théo Hendriks ◽  
Christian Slomianny ◽  
Jacques Vasseur ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Somatic Embryogenesis ◽  
Cell Walls ◽  
Ultrastructural Changes ◽  
Outer Cell ◽  
Embryogenic Cell ◽  
Transmission Electron ◽  
Outer Cell Wall

In Cichorium hybrid clone 474 (C. intybus L. var. sativum × C. endivia L. var. latifolia), direct somatic embryogenesis was induced from roots. Using transmission electron microscopy, we followed the ultrastructural changes of the outer cell wall in relation to embryo developmental stage. During the transition from an embryogenic cell to a somatic embryo, the differentiation of the outer cell wall involved both deposition and rearrangement processes. During the first divisions, the cell wall of few-celled embryos still enclosed in the root tissue appeared as a large amorphous layer of cellulose, thicker than the cell walls of the root cortex cells. When the proembryo emerged from the root cells, the outer wall surface exhibited a fibrillar material designated as the supraembryonic network. As this network disappeared, the outer cell wall changed organization, and two domains were distinguished. At the torpedo stage, the outer cell wall was more compact without any gaps and the protoderm was differentiated. Immunolocalization of an epitope recognised by JIM5 antibody revealed the unesterified nature of the supraembryonic network. Such pectins were also located at the outer third of the outer cell wall of protodermal cells as well as in the intercellular spaces. Highly methylesterified pectins recognized by JIM7 antibodies were slightly present in the cell walls during the embryogenesis process. The different stages of the outer cell wall differentiation as well as the development of the transient supraembryonic network are described, and its possible roles in somatic embryogenesis are proposed.Key words: cell differentiation, cell wall, Cichorium (chicory), pectin, somatic embryogenesis, transmission electron microscopy.

Use of immunogold cytochemistry to detect Mn(II)-dependent and lignin peroxidases in wood degraded by the white rot fungi Phanerochaete chrysosporium and Lentinula edodes

1990 ◽  
Vol 68 (4) ◽  
pp. 920-933 ◽  
Author(s):  
G. Daniel ◽  
B. Pettersson ◽  
T. Nllsson ◽  
J. Volc
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Phanerochaete Chrysosporium ◽  
Cell Walls ◽  
Lentinula Edodes ◽  
White Rot ◽  
Transmission Electron ◽  
Lignin Peroxidases ◽  
Immunogold Cytochemistry

Using antibodies raised against Mn(II)-dependent peroxidase and transmission electron microscopy immunogold cytochemistry, the spatial distribution of Mn(II)-dependent peroxidase during degradation of wood and wood fragments by Phanerochaete chrysosporium and Lentinula edodes was studied. In P. chrysosporium, the enzyme was localized in peripheral regions of the fungal hyphae on the cell membrane, on membranes of vesicule-like structures, and on the cell wall. The cytoplasmic distribution of Mn(II)-dependent peroxidase appeared similar to that of lignin peroxidase, as determined by double immunogold labeling procedures and antibodies raised against lignin peroxidase. In wood blocks of Betula verrucosa degraded by P. chrysosporium and L. edodes, Mn(II)-dependent peroxidase was detected on all wood cell wall layers showing signs of decay, whether at early or advanced stages of attack. In particular, the enzyme was localized in zones of degradation produced within the S2 wood cell walls. These regions displayed a looser, more open fibrillar structure than unattacked wood cell walls and were readily penetrated by purified preparations of Mn(II)-dependent and lignin peroxidases. With L. edodes, Mn(II)-dependent peroxidase was found to accumulate in middle lamellar regions selectively degraded by the fungus. Mn(II)-dependent peroxidase diffusion into undecayed wood cell walls was not observed. Key words: Mn(II)-dependent peroxidase, Phanerochaete chrysosporium, Lentinula edodes, immunogold cytochemistry, white rot decay, transmission electron microscopy.

Transmission Electron Microscopy, Fluorescence Microscopy, and Confocal Raman Microscopic Analysis of Ultrastructural and Compositional Heterogeneity of Cornus alba L. Wood Cell Wall

2013 ◽  
Vol 19 (1) ◽  
pp. 243-253 ◽  
Author(s):  
Jianfeng Ma ◽  
Zhe Ji ◽  
Xia Zhou ◽  
Zhiheng Zhang ◽  
Feng Xu
Keyword(s):  
Cell Wall ◽  
Fluorescence Microscopy ◽  
Cell Walls ◽  
Middle Lamella ◽  
Plant Cell Walls ◽  
Cornus Alba ◽  
Transmission Electron ◽  
Pit Membrane ◽  
Ray Parenchyma

AbstractTransmission electron microscopy (TEM), fluorescence microscopy, and confocal Raman microscopy can be used to characterize ultrastructural and compositional heterogeneity of plant cell walls. In this study, TEM observations revealed the ultrastructural characterization of Cornus alba L. fiber, vessel, axial parenchyma, ray parenchyma, and pit membrane between cells, notably with the ray parenchyma consisting of two well-defined layers. Fluorescence microscopy evidenced that cell corner middle lamella was more lignified than adjacent compound middle lamella and secondary wall with variation in lignification level from cell to cell. In situ Raman images showed that the inhomogeneity in cell wall components (cellulose and lignin) among different cells and within morphologically distinct cell wall layers. As the significant precursors of lignin biosynthesis, the pattern of coniferyl alcohol and aldehyde (joint abbreviation Lignin-CAA for both structures) distribution in fiber cell wall was also identified by Raman images, with higher concentration occurring in the fiber secondary wall where there was the highest cellulose concentration. Moreover, noteworthy was the observation that higher concentration of lignin and very minor amounts of cellulose were visualized in the pit membrane areas. These complementary microanalytical methods provide more accurate and complete information with regard to ultrastructural and compositional characterization of plant cell walls.

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