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Seong H. Kim - One of the best experts on this subject based on the ideXlab platform.
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shear induced unidirectional deposition of bacterial Cellulose Microfibrils using rising bubble stream cultivation
Carbohydrate Polymers, 2021Co-Authors: Inseok Chae, Syed M Q Bokhari, Xing Chen, Ke Liu, Ali Borhan, Venkatraman Gopalan, Jeffrey M Catchmark, Seong H. KimAbstract:In crystalline Cellulose I, all glucan chains are ordered from reducing ends to non-reducing ends. Thus, the polarity of individual chains is added forming a large dipole within the crystal. If one can engineer unidirectional alignment (parallel packing) of Cellulose crystals, then it might be possible to utilize the material properties originating from polar crystalline structures. However, most post-synthesis manipulation methods reported so far can only achieve the uniaxial alignment with bi-directionality (antiparallel packing). Here, we report a method to induce the parallel packing of bacterial Cellulose Microfibrils by applying unidirectional shear stress during the synthesis and deposition through the rising bubble stream in a culture medium. Driving force for the alignment is explained with mathematical estimation of the shear stress. Evidences of the parallel alignment of crystalline Cellulose Iα domains were obtained using nonlinear optical spectroscopy techniques.
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distinguishing mesoscale polar order unidirectional vs bidirectional of Cellulose Microfibrils in plant cell walls using sum frequency generation spectroscopy
Journal of Physical Chemistry B, 2020Co-Authors: Mohamadamin Makarem, Daniel M Durachko, Daniel J. Cosgrove, Yoshiharu Nishiyama, Xiaoran Xin, Seong H. KimAbstract:Cellulose in plant cell walls are synthesized as crystalline Microfibrils with diameters of 3-4 nm and lengths of around 1-10 μm. These Microfibrils are known to be the backbone of cell walls, and their multiscale three-dimensional organization plays a critical role in cell wall functions including plant growth and recalcitrance to degradation. The mesoscale organization of Microfibrils over a 1-100 nm range in cell walls is challenging to resolve because most characterization techniques investigating this length scale suffer from low spatial resolution, sample preparation artifacts, or inaccessibility of specific cell types. Here, we report a sum frequency generation (SFG) study determining the mesoscale polarity of Cellulose Microfibrils in intact plant cell walls. SFG is a nonlinear optical spectroscopy technique sensitive to the molecular-to-mesoscale order of noncentrosymmetric domains in amorphous matrices. However, the quantitative theoretical model to unravel the effect of polarity in packing of noncentrosymmetric domains on SFG spectral features has remained unresolved. In this work, we show how the phase synchronization principle of the SFG process is used to predict the relative intensities of vibrational modes with different polar angles from the noncentrosymmetric domain axis. Applying this model calculation for the first time and employing SFG microscopy, we found that Cellulose Microfibrils in certain xylem cell walls are deposited unidirectionally (or biased in one direction) instead of the bidirectional polarity which was believed to be dominant in plant cell walls from volume-averaged characterizations of macroscopic samples. With this advancement in SFG analysis, one can now determine the relative polarity of noncentrosymmetric domains such as crystalline biopolymers interspersed in amorphous polymer matrices, which will open opportunities to study new questions that have not been conceived in the past.
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dehydration induced physical strains of Cellulose Microfibrils in plant cell walls
Carbohydrate Polymers, 2018Co-Authors: Shixin Huang, Yunzhen Zheng, Daniel J. Cosgrove, Mohamadamin Makarem, Sarah N Kiemle, Esther W Gomez, Enrique D Gomez, Seong H. KimAbstract:The effect of dehydration of plant cell walls on the physical status of Cellulose Microfibrils (CMFs) interspersed in pectin matrices was studied. Vibrational sum frequency generation (SFG) spectroscopy analysis of Cellulose revealed reversible changes in spectral features upon dehydration and rehydration of onion epidermal walls used as a model primary cell wall (PCW). Combined with microscopic imaging and indentation modulus data, such changes could be attributed to local strains in CMFs due to the collapse of the pectin matrix upon dehydration. X-ray diffraction (XRD) showed that the (200) spacing of Cellulose in dried PCWs is larger than that of Cellulose Iβ obtained from tunicates. Thus, the modulus of CMFs in PCWs would be lower than those of highly-crystalline Cellulose Iβ and inhomogeneous local bending or strain of CMFs could occur readily during the physical collapse of pectin matrix due to dehydration.
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In vitro synthesis of Cellulose Microfibrils by a membrane protein from protoplasts of the non-vascular plant Physcomitrella patens.
The Biochemical journal, 2015Co-Authors: Sung Hyun Cho, Kabindra Kafle, Yong Bum Park, Ian T. Sines, Venkata Giridhar Poosarla, Venkata R. Vepachedu, Seong H. Kim, Manish Kumar, B. Tracy NixonAbstract:Plant Cellulose synthases (CesAs) form a family of membrane proteins that are associated with hexagonal structures in the plasma membrane called CesA complexes (CSCs). It has been difficult to purify plant CesA proteins for biochemical and structural studies. We describe CesA activity in a membrane protein preparation isolated from protoplasts of Physcomitrella patens overexpressing haemagglutinin (HA)-tagged PpCesA5. Incubating the membrane preparation with UDP-glucose predominantly produced Cellulose. Negative-stain EM revealed Microfibrils. Cellulase bound to and degraded these Microfibrils. Vibrational sum frequency generation (SFG) spectroscopic analysis detected the presence of crystalline Cellulose in the Microfibrils. Putative CesA proteins were frequently observed attached to the microfibril ends. Combined cross-linking and gradient centrifugation showed bundles of Cellulose Microfibrils with larger particle aggregates, possibly CSCs. These results suggest that P. patens is a useful model system for biochemical and structural characterization of plant CSCs and their components.
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Vibrational sum-frequency-generation (SFG) spectroscopy study of the structural assembly of Cellulose Microfibrils in reaction woods
Cellulose, 2014Co-Authors: Kabindra Kafle, Yong Bum Park, Rui Shi, Christopher M. Lee, Ashutosh Mittal, Ying-hsuan Sun, Sunkyu Park, Vincent Chiang, Seong H. KimAbstract:The Cellulose microfibril assemblies in secondary cell walls of tension wood and compression wood were studied with vibrational sum frequency generation (SFG) spectroscopy. The tension wood contains the gelatinous layer with highly-crystalline and highly-aligned Cellulose Microfibrils. The SFG spectral features of tension wood changed depending on the azimuth angle between the polarization of the incident IR beam and the preferential alignment axis of the Cellulose Microfibrils. The SFG spectra of the compression wood did not show any dependence on the azimuth angle, implying that the overall orientation of Cellulose Microfibrils in compression wood is not highly aligned. Instead, the decrease of Cellulose content in compression wood brought about larger separation between Cellulose Microfibrils, which was manifested as changes in CH_2/OH intensity ratio in SFG spectra. These results implied that SFG spectral features are sensitive to Cellulose microfibril alignments and inter-fibrillar separations.
Krassimir P Velikov - One of the best experts on this subject based on the ideXlab platform.
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rheology of oil in water emulsions stabilised by native Cellulose Microfibrils in primary plant cells dispersions
Food Structure, 2021Co-Authors: Emma M Nomena, Micah Van Der Vaart, Panayiotis Voudouris, Krassimir P VelikovAbstract:Abstract We have investigated the rheology of oil-in-water emulsions stabilised in a dispersion of Cellulose microfibril – biopolymer hybrid networks. In these systems, Pickering-like stabilisation from individual CMFs and bundles is provided in combination with a viscoelastic fibrillar network that prevents the droplets from coalescing. The complex modulus of emulsions in such dispersions was measured for oil concentrations ranging from 5 to 50 wt%. Models for the complex modulus of a suspension of particles in a viscoelastic matrix are used to predict the modulus of such an emulsion for different oil and microfibril concentrations. It was found that introducing the effect of the influence of the dispersed phase on the deagglomeration of the CMF after a second homogenisation step allows for a good agreement with the experimental data for both models at high concentration of Cellulose Microfibrils. However, at moderate oil concentrations, the model overpredicts the complex modulus, as the presence of droplet clusters decreases the value of the measured modulus.
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drying of pickering emulsions in a viscoelastic network of Cellulose Microfibrils
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019Co-Authors: Emma M Nomena, Krassimir P VelikovAbstract:Abstract Oil-in-water Pickering emulsions at high volume fractions (50 wt % oil) are prepared using Cellulose Microfibrils (CMF) from plant cell wall materials as emulsifiers and stabilizer. Confocal microscopy is used to monitor the changing CMF network over time and the rate of oil droplet coalescence. Without addition of glycerol the drying emulsion quickly coalesces, and a significant oil separation ensues. The rate of coalescence and the percentage of coalescence droplets and oil separation decrease as the concentration of CMF is increased. Addition of glycerol into the emulsions decreases the extent of droplet coalescence and oil separation. At 10 wt% added glycerol, coalescence could not be prevented but oil separation is minimal: the oil is mainly contained into honeycomb shaped cells made of CMF and glycerol. The results demonstrate the influence of the aqueous phase on the coalescence and film forming properties of CMF stabilized Pickering emulsions.
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unravelling the mechanism of stabilization and microstructure of oil in water emulsions by native Cellulose Microfibrils in primary plant cells dispersions
ACS Applied Bio Materials, 2018Co-Authors: Emma M Nomena, Caroline Remijn, Faranaaz Rogier, Micah Van Der Vaart, Panayiotis Voudouris, Krassimir P VelikovAbstract:It is long known that oil-in-water emulsions can be stable against coalescence in homogenized plant cell wall dispersions because of the presence of surface-active biopolymers. When plant cell wall material is homogenized to the extent of deagglomeration of the Cellulose Microfibrils (CMFs), a much more complex dispersed system is obtained. Here we show that in such complex systems both surface active soluble polymers and individual CMFs are at the origin of this stabilization against coalescence, as they form a shell around the oil droplets providing Pickering-like stabilization. Individual CMFs and bundles of them in the presence of soluble biopolymers form a hybrid network in the continuous phase linking the droplets, creating a viscoelastic network that prevents the droplets from coalescing. Depletion induced attraction caused by soluble biopolymers and dispersed CMFs induces the formation of oil droplet clusters at low CMF concentrations leading to a highly heterogeneous distribution of oil droplets....
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Unravelling the Mechanism of Stabilization and Microstructure of Oil-in-Water Emulsions by Native Cellulose Microfibrils in Primary Plant Cells Dispersions
2018Co-Authors: Emma M Nomena, Caroline Remijn, Faranaaz Rogier, Micah Van Der Vaart, Panayiotis Voudouris, Krassimir P VelikovAbstract:It is long known that oil-in-water emulsions can be stable against coalescence in homogenized plant cell wall dispersions because of the presence of surface-active biopolymers. When plant cell wall material is homogenized to the extent of deagglomeration of the Cellulose Microfibrils (CMFs), a much more complex dispersed system is obtained. Here we show that in such complex systems both surface active soluble polymers and individual CMFs are at the origin of this stabilization against coalescence, as they form a shell around the oil droplets providing Pickering-like stabilization. Individual CMFs and bundles of them in the presence of soluble biopolymers form a hybrid network in the continuous phase linking the droplets, creating a viscoelastic network that prevents the droplets from coalescing. Depletion induced attraction caused by soluble biopolymers and dispersed CMFs induces the formation of oil droplet clusters at low CMF concentrations leading to a highly heterogeneous distribution of oil droplets. This effect diminishes at high CMF concentrations at which the strong viscoelastic network arrests the droplets. These findings are important steps toward controlling complex dispersed systems comprising CMF–polymers mixtures with a second liquid or solid dispersed phase
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revealing and quantifying the three dimensional nano and microscale structures in self assembled Cellulose Microfibrils in dispersions
ACS omega, 2017Co-Authors: Srivatssan Mohan, Krassimir P Velikov, Anke Kuijk, Jissy Jose, Sandra J Veen, Alfons Van BlaaderenAbstract:Cellulose Microfibrils (CMFs) are an important nanoscale building block in many novel biobased functional materials. The spatial nano- and microscale organization of the CMFs is a crucial factor for defining the properties of these materials. Here, we report for the first time a direct three-dimensional (3D) real-space analysis of individual CMFs and their networks formed after ultrahigh-shear-induced transient deagglomeration and self-assembly in a solvent. Using point-scanning confocal microscopy combined with tracking the centerlines of the fibrils and their junctions by a stretching open active contours method, we reveal that dispersions of the native CMFs assemble into highly heterogeneous networks of individual fibrils and bundles. The average network mesh size decreases with increasing CMF volume fraction. The cross-sectional width and the average length between the twists in the ribbon-shaped CMFs are directly determined and compared well with that of fibrils in the dried state. Finally, the gener...
Michael C. Jarvis - One of the best experts on this subject based on the ideXlab platform.
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HemiCellulose binding and the spacing of Cellulose Microfibrils in spruce wood
Cellulose, 2020Co-Authors: Lynne H. Thomas, Anne Martel, Isabelle Grillo, Michael C. JarvisAbstract:Cellulose Microfibrils in conifers, as in other woody materials, are aggregated into loose bundles called macrofibrils. The centre-to-centre spacing of the Microfibrils within these macrofibrils can be estimated from the position of a broad diffraction peak in small-angle neutron scattering (SANS) after deuteration. A known spacing of 3.0 nm, increasing with moisture content, is consistent with direct microfibril to microfibril contact. However recent evidence indicates that conifer Microfibrils are partially coated with bound xylan chains, and possibly with lignin and galactoglucomannan, implying a wider centre-to-centre spacing as found in angiosperm wood. Delignification of spruce wood allowed a weak SANS peak to be observed without measurable change in spacing. By deuterating spruce wood in mildly alkaline D_2O and then re-equilibrating with ambient H_2O, deuterium atoms were trapped in a position that gave a 3.8 nm microfibril spacing under dry conditions as in angiosperm wood, instead of the 3.0 nm spacing normally observed in conifers. After conventional vapour deuteration of spruce wood a minor peak at 3.8 nm could be fitted in addition to the 3.0 nm peak. These observations are consistent with some microfibril segments being separated by bound xylan chains as in angiosperms, in addition to the microfibril segments that are in direct contact.
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structure of native Cellulose Microfibrils the starting point for nanoCellulose manufacture
Philosophical Transactions of the Royal Society A, 2018Co-Authors: Michael C. JarvisAbstract:There is an emerging consensus that higher plants synthesize Cellulose Microfibrils that initially comprise 18 chains. However, the mean number of chains per microfibril in situ is usually greater than 18, sometimes much greater. Microfibrils from woody tissues of conifers, grasses and dicotyledonous plants, and from organs like cotton hairs, all differ in detailed structure and mean diameter. Diameters increase further when aggregated Microfibrils are isolated. Because surface chains differ, the tensile properties of the Cellulose may be augmented by increasing microfibril diameter. Association of Microfibrils with anionic polysaccharides in primary cell walls and mucilages leads to in vivo mechanisms of disaggregation that may be relevant to the preparation of nanofibrillar Cellulose products. For the preparation of nanocrystalline Celluloses, the key issue is the nature and axial spacing of disordered domains at which axial scission can be initiated. These disordered domains do not, as has often been suggested, take the form of large blocks occupying much of the length of the microfibril. They are more likely to be located at chain ends or at places where the microfibril has been mechanically damaged, but their structure and the reasons for their sensitivity to acid hydrolysis need better characterization. This article is part of a discussion meeting issue ‘New horizons for Cellulose nanotechnology’.
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Structure and spacing of Cellulose Microfibrils in woody cell walls of dicots
Cellulose, 2014Co-Authors: Lynne H. Thomas, Clemens M Altaner, Anne Martel, Isabelle Grillo, V. Trevor Forsyth, Michael C. JarvisAbstract:The structure of Cellulose Microfibrils in situ in wood from the dicotyledonous (hardwood) species cherry and birch, and the vascular tissue from sunflower stems, was examined by wide-angle X-ray and neutron scattering (WAXS and WANS) and small-angle neutron scattering (SANS). Deuteration of accessible Cellulose chains followed by WANS showed that these chains were packed at similar spacings to crystalline Cellulose, consistent with their inclusion in the microfibril dimensions and with a location at the surface of the Microfibrils. Using the Scherrer equation and correcting for considerable lateral disorder, the microfibril dimensions of cherry, birch and sunflower Microfibrils perpendicular to the [200] crystal plane were estimated as 3.0, 3.4 and 3.3 nm respectively. The lateral dimensions in other directions were more difficult to correct for disorder but appeared to be 3 nm or less. However for cherry and sunflower, the microfibril spacing estimated by SANS was about 4 nm and was insensitive to the presence of moisture. If the microfibril width was 3 nm as estimated by WAXS, the SANS spacing suggests that a non-cellulosic polymer segment might in places separate the aggregated Cellulose Microfibrils.
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nanostructure of Cellulose Microfibrils in spruce wood
Proceedings of the National Academy of Sciences of the United States of America, 2011Co-Authors: Anwesha N Fernandes, Craig J. Kennedy, Lynne H. Thomas, V T Forsyth, Pete Callow, Clemens M Altaner, David C. Apperley, Michael C. JarvisAbstract:The structure of Cellulose Microfibrils in wood is not known in detail, despite the abundance of Cellulose in woody biomass and its importance for biology, energy, and engineering. The structure of the Microfibrils of spruce wood Cellulose was investigated using a range of spectroscopic methods coupled to small-angle neutron and wide-angle X-ray scattering. The scattering data were consistent with 24-chain Microfibrils and favored a “rectangular” model with both hydrophobic and hydrophilic surfaces exposed. Disorder in chain packing and hydrogen bonding was shown to increase outwards from the microfibril center. The extent of disorder blurred the distinction between the I alpha and I beta allomorphs. Chains at the surface were distinct in conformation, with high levels of conformational disorder at C-6, less intramolecular hydrogen bonding and more outward-directed hydrogen bonding. Axial disorder could be explained in terms of twisting of the Microfibrils, with implications for their biosynthesis.
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Hydration effects on spacing of primary-wall Cellulose Microfibrils: a small angle X-ray scattering study
Cellulose, 2007Co-Authors: Craig J. Kennedy, Adriana Sturcova, Michael C. Jarvis, Timothy J. WessAbstract:Celery collenchyma cell walls are typical of primary plant cell walls in their composition but contain unusually well-oriented Cellulose Microfibrils that are packed with more regularity than normal, permitting small-angle X-ray scattering (SAXS) experiments that would not otherwise be possible. Small-angle scattering data were obtained for the cell walls in essentially their native state and for isolated Cellulose, in a fibrous form that retained the physical shape and microfibril orientation of the native cell walls. The scattering patterns showed a distinct peak attributed to the interference contribution to the convolution of form and interference functions. The position of the peak attributed to the interference function implied a mean centre-to-centre microfibril spacing of approximately 3.2 nm in dry isolated Cellulose and 3.8 nm in dry cell walls. Hydration increased the mean microfibril spacing in the cell walls to 5.4 nm but had only a small effect on the mean microfibril spacing of isolated Cellulose. In the scattering profile from intact, hydrated cell walls it was just possible to discern the position of the first Bessel minimum, from which a microfibril diameter in the range 3.1–3.6 nm may be estimated. This estimate is likely to include attached hemiCellulose chains. Porod plots of scattering intensity indicated a relatively sharp interface between Microfibrils and their immediate surroundings. The SAXS data imply that Cellulose Microfibrils 2.6–3.0 nm in diameter are not quite in lateral contact with one another in the isolated Cellulose and are augmented by hemiCelluloses and separated by readily hydrated matrix polysaccharides in the native plant cell wall.
Daniel J. Cosgrove - One of the best experts on this subject based on the ideXlab platform.
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distinguishing mesoscale polar order unidirectional vs bidirectional of Cellulose Microfibrils in plant cell walls using sum frequency generation spectroscopy
Journal of Physical Chemistry B, 2020Co-Authors: Mohamadamin Makarem, Daniel M Durachko, Daniel J. Cosgrove, Yoshiharu Nishiyama, Xiaoran Xin, Seong H. KimAbstract:Cellulose in plant cell walls are synthesized as crystalline Microfibrils with diameters of 3-4 nm and lengths of around 1-10 μm. These Microfibrils are known to be the backbone of cell walls, and their multiscale three-dimensional organization plays a critical role in cell wall functions including plant growth and recalcitrance to degradation. The mesoscale organization of Microfibrils over a 1-100 nm range in cell walls is challenging to resolve because most characterization techniques investigating this length scale suffer from low spatial resolution, sample preparation artifacts, or inaccessibility of specific cell types. Here, we report a sum frequency generation (SFG) study determining the mesoscale polarity of Cellulose Microfibrils in intact plant cell walls. SFG is a nonlinear optical spectroscopy technique sensitive to the molecular-to-mesoscale order of noncentrosymmetric domains in amorphous matrices. However, the quantitative theoretical model to unravel the effect of polarity in packing of noncentrosymmetric domains on SFG spectral features has remained unresolved. In this work, we show how the phase synchronization principle of the SFG process is used to predict the relative intensities of vibrational modes with different polar angles from the noncentrosymmetric domain axis. Applying this model calculation for the first time and employing SFG microscopy, we found that Cellulose Microfibrils in certain xylem cell walls are deposited unidirectionally (or biased in one direction) instead of the bidirectional polarity which was believed to be dominant in plant cell walls from volume-averaged characterizations of macroscopic samples. With this advancement in SFG analysis, one can now determine the relative polarity of noncentrosymmetric domains such as crystalline biopolymers interspersed in amorphous polymer matrices, which will open opportunities to study new questions that have not been conceived in the past.
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the shape of native plant Cellulose Microfibrils
Scientific Reports, 2018Co-Authors: James D. Kubicki, Daniel P. Oehme, Daisuke Sawada, Hugh Oneill, Hui Yang, Daniel J. CosgroveAbstract:Determining the shape of plant Cellulose Microfibrils is critical for understanding plant cell wall molecular architecture and conversion of Cellulose into biofuels. Only recently has it been determined that these Cellulose Microfibrils are composed of 18 Cellulose chains rather than 36 polymers arranged in a diamond-shaped pattern. This study uses density functional theory calculations to model three possible habits for the 18-chain microfibril and compares the calculated energies, structures, 13C NMR chemical shifts and WAXS diffractograms of each to evaluate which shape is most probable. Each model is capable of reproducing experimentally-observed data to some extent, but based on relative theoretical energies and reasonable reproduction of all variables considered, a microfibril based on 5 layers in a 34443 arrangement is predicted to be the most probable. A habit based on a 234432 arrangement is slightly less favored, and a 6 × 3 arrangement is considered improbable.
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dehydration induced physical strains of Cellulose Microfibrils in plant cell walls
Carbohydrate Polymers, 2018Co-Authors: Shixin Huang, Yunzhen Zheng, Daniel J. Cosgrove, Mohamadamin Makarem, Sarah N Kiemle, Esther W Gomez, Enrique D Gomez, Seong H. KimAbstract:The effect of dehydration of plant cell walls on the physical status of Cellulose Microfibrils (CMFs) interspersed in pectin matrices was studied. Vibrational sum frequency generation (SFG) spectroscopy analysis of Cellulose revealed reversible changes in spectral features upon dehydration and rehydration of onion epidermal walls used as a model primary cell wall (PCW). Combined with microscopic imaging and indentation modulus data, such changes could be attributed to local strains in CMFs due to the collapse of the pectin matrix upon dehydration. X-ray diffraction (XRD) showed that the (200) spacing of Cellulose in dried PCWs is larger than that of Cellulose Iβ obtained from tunicates. Thus, the modulus of CMFs in PCWs would be lower than those of highly-crystalline Cellulose Iβ and inhomogeneous local bending or strain of CMFs could occur readily during the physical collapse of pectin matrix due to dehydration.
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nanoscale movements of Cellulose Microfibrils in primary cell walls
Nature plants, 2017Co-Authors: Tian Zhang, Dimitrios Vavylonis, Daniel M Durachko, Daniel J. CosgroveAbstract:The growing plant cell wall is commonly considered to be a fibre-reinforced structure whose strength, extensibility and anisotropy depend on the orientation of crystalline Cellulose Microfibrils, their bonding to the polysaccharide matrix and matrix viscoelasticity1–4. Structural reinforcement of the wall by stiff Cellulose Microfibrils is central to contemporary models of plant growth, mechanics and meristem dynamics4–12. Although passive microfibril reorientation during wall extension has been inferred from theory and from bulk measurements13–15, nanometre-scale movements of individual Microfibrils have not been directly observed. Here we combined nanometre-scale imaging of wet cell walls by atomic force microscopy (AFM) with a stretching device and endoglucanase treatment that induces wall stress relaxation and creep, mimicking wall behaviours during cell growth. Microfibril movements during forced mechanical extensions differ from those during creep of the enzymatically loosened wall. In addition to passive angular reorientation, we observed a diverse repertoire of microfibril movements that reveal the spatial scale of molecular connections between Microfibrils. Our results show that wall loosening alters microfibril connectivity, enabling microfibril dynamics not seen during mechanical stretch. These insights into microfibril movements and connectivities need to be incorporated into refined models of plant cell wall structure, growth and morphogenesis. Plant cell growth requires cell wall extension. Here, the nanoscale movement of Cellulose Microfibrils in onion primary cell wall is imaged by atomic force microscopy and compared under mechanical extension versus enzymatic loosening.
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nanoscale movements of Cellulose Microfibrils in primary cell walls
Nature plants, 2017Co-Authors: Tian Zhang, Dimitrios Vavylonis, Daniel M Durachko, Daniel J. CosgroveAbstract:The growing plant cell wall is commonly considered to be a fibre-reinforced structure whose strength, extensibility and anisotropy depend on the orientation of crystalline Cellulose Microfibrils, their bonding to the polysaccharide matrix and matrix viscoelasticity1-4. Structural reinforcement of the wall by stiff Cellulose Microfibrils is central to contemporary models of plant growth, mechanics and meristem dynamics4-12. Although passive microfibril reorientation during wall extension has been inferred from theory and from bulk measurements13-15, nanometre-scale movements of individual Microfibrils have not been directly observed. Here we combined nanometre-scale imaging of wet cell walls by atomic force microscopy (AFM) with a stretching device and endoglucanase treatment that induces wall stress relaxation and creep, mimicking wall behaviours during cell growth. Microfibril movements during forced mechanical extensions differ from those during creep of the enzymatically loosened wall. In addition to passive angular reorientation, we observed a diverse repertoire of microfibril movements that reveal the spatial scale of molecular connections between Microfibrils. Our results show that wall loosening alters microfibril connectivity, enabling microfibril dynamics not seen during mechanical stretch. These insights into microfibril movements and connectivities need to be incorporated into refined models of plant cell wall structure, growth and morphogenesis.
Junji Sugiyama - One of the best experts on this subject based on the ideXlab platform.
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direct investigation of the structural properties of tension wood Cellulose Microfibrils using microbeam x ray fibre diffraction
Holzforschung, 2006Co-Authors: Martin Muller, Manfred Burghammer, Junji SugiyamaAbstract:Single tension-wood fibres from poplar were investigated using a synchrotron radiation X-ray microbeam. The resulting diffraction patterns are highly resolved (smallest d-spacing 0.11 nm). In the gelatinous layer, Cellulose Microfibrils of high perfection are found in almost ideal parallel alignment. Their cross-section is approximately four-fold greater than that of Microfibrils in the S2 layer of the same wood cell. The results are discussed in terms of the influence of encrusting cell wall polymers and Cellulose biosynthesis on the structure of wood Cellulose Microfibrils. In temperature-dependent experiments, the low-temperature thermal expansion coefficients of crystalline Cellulose were determined.
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mechanical behavior of Cellulose Microfibrils in tension wood in relation with maturation stress generation
Biophysical Journal, 2006Co-Authors: Bruno Clair, Hiroyuki Yamamoto, Tancrede Almeras, Takashi Okuyama, Junji SugiyamaAbstract:A change in Cellulose lattice spacing can be detected during the release of wood maturation stress by synchrotron x-ray diffraction experiment. The lattice strain was found to be the same order of magnitude as the macroscopic strain. The fiber repeat distance, 1.033 nm evaluated for tension wood after the release of maturation stress was equal to the conventional wood values, whereas the value before stress release was larger, corresponding to a fiber repeat of 1.035 nm, nearly equal to that of cotton and ramie. Interestingly, the fiber repeat varied from 1.033 nm for wood to 1.040 nm for algal Cellulose, with an increasing order of lateral size of Cellulose Microfibrils so far reported. These lines of experiments demonstrate that, before the stress release, the Cellulose was in a state of tension, which is, to our knowledge, the first experimental evidence supporting the assumption that tension is induced in Cellulose Microfibrils.
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preferential uniplanar orientation of Cellulose Microfibrils reinvestigated by the ftir technique
Cellulose, 2006Co-Authors: Yoshiki Horikawa, Takao Itoh, Junji SugiyamaAbstract:A simple detection method to observe the uniplanar orientation behavior of native Cellulose Microfibrils to the cell wall surface by using Fourier transform infrared (FTIR) spectroscopy in the transmission mode is reported. Four bands at 1372, 1355, 1337, and 1317 cm−1 (the latter two have been mentioned previously by Liang and Marchessault (1960, J. Polym. Sci. 43: 85–100)) were found to be sensitive to such orientation: the two middle bands at 1355 and 1337 cm−1 increase remarkably when the 0.60–61 nm lattice planes lie parallel to the cell wall surfaces. The reverse was true when the 0.53–54 nm lattice planes oriented preferentially. Polarization of the two bands at 1372 and 1355 cm−1 was parallel, while that of the other two bands at lower wavenumbers, i.e., at 1337 and 1317 cm−1, was perpendicular to the molecular axis of Cellulose. These bands were assigned to OH-related motion, probably to in-plane OH bending, as reported by Marechal and Chanzy (2000, J. Mol. Spectrosc. 523: 183–196).
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geometric phase analysis of lattice images from algal Cellulose Microfibrils
Polymer, 2003Co-Authors: Tomoya Imai, Jeanluc Putaux, Junji SugiyamaAbstract:A geometric phase analysis has been applied to high-resolution transmission electron microscopy images from algal Cellulose microcrystals. The pictures were decomposed into images containing selectively the amplitude or phase information associated to selected Bragg reflections. Compared with Ib (monoclinic)-rich Cellulose Microfibrils, Ia(triclinic)-rich Microfibrils were found to be more heterogeneous when viewed along the H-bonding sheets. As a microfibril twist and radiation damage could not be totally ruled out as having an effect on the lattice image, this result has to be considered with care when used in order to survey the distribution of different allomorphs in a Cellulose microfibril. However, the geometric phase analysis of noisy low dose high-resolution images appears as a promising new method to investigate polymer crystals and the distribution of domains having different structures or containing lattice distortions. q 2002 Elsevier Science Ltd. All rights reserved.
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the enzymatic susceptibility of Cellulose Microfibrils of the algal bacterial type and the cotton ramie type
Carbohydrate Research, 1997Co-Authors: Noriko Hayashi, Junji Sugiyama, Takeshi Okano, Mitsuro IshiharaAbstract:Abstract Two types of substrates, the algal-bacterial type (rich in Cellulose I α ) Cellulose and the cotton-ramie type (dominant in Cellulose I β ) Cellulose, were degraded comparatively by Trichoderma viride cellulase. The algal-bacterial type Cellulose microfibril was more susceptible than the cotton-ramie type. The residual Cellulose Microfibrils were observed by TEM and analyzed by FTIR and electron diffraction. It becomes clear that the residual Cellulose of the algal-bacterial type Cellulose was getting rich in the Cellulose I β with the lapse time of cellulase treatment. These results indicate that the Cellulose I α in the microfibril of the algal-bacterial type Cellulose is hydrolyzed preferentially by the cellulase.