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E A Bayer - One of the best experts on this subject based on the ideXlab platform.
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Digestion of crystalline cellulose substrates by the clostridium thermocellum cellulosome: structural and morphological aspects.
The Biochemical journal, 1999Co-Authors: Claire Boisset, Henri Chanzy, Bernard Henrissat, Raphael Lamed, Yuval Shoham, E A BayerAbstract:The action of cellulosomes from Clostridium thermocellum on model cellulose microfibrils from Acetobacter xylinum and cellulose microcrystals from Valonia ventricosa was investigated. The biodegradation of these substrates was followed by transmission electron microscopy, Fourier-transform IR spectroscopy and X-ray diffraction analysis, as a function of the extent of degradation. The cellulosomes were very effective in catalysing the complete digestion of bacterial cellulose, but the total degradation of Valonia microcrystals was achieved more slowly. Ultrastructural observations during the digestion process suggested that the rapid degradation of bacterial cellulose was the result of a very efficient synergistic action of the various enzymic components that are attached to the scaffolding protein of the cellulosomes. The degraded Valonia sample assumed various shapes, ranging from thinned-down microcrystals to crystals where one end was pointed and the other intact. This complexity may be correlated with the multi-enzyme content of the cellulosomes and possibly to a diversity of the cellulosome composition within a given batch. Another aspect of the digestion of model celluloses by cellulosomes is the relative invariability of their crystallinity, together with their Ialpha/Ibeta composition throughout the degradation process. Comparison of the action of cellulosomes with that of fungal enzymes indicated that the degradation of cellulose crystals by cellulosomes occurred with only limited levels of processivity, in contrast with the observations reported for fungal enzymes. The findings were consistent with a mechanism whereby initial attack by a cellulosome of an individual cellulose crystal results in its 'commitment' towards complete degradation.
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digestion of crystalline cellulose substrates by the clostridium thermocellum cellulosome structural and morphological aspects
Biochemical Journal, 1999Co-Authors: Claire Boisset, Henri Chanzy, Bernard Henrissat, Raphael Lamed, Yuval Shoham, E A BayerAbstract:The action of cellulosomes from Clostridium thermocellum on model cellulose microfibrils from Acetobacter xylinum and cellulose microcrystals from Valonia aentricosa was investigated. The biodegradation of these substrates was followed by transmission electron microscopy, Fourier-transform IR spectroscopy and Xray diraction analysis, as a function of the extent of degradation. The cellulosomes were very eective in catalysing the complete digestion of bacterial cellulose, but the total degradation of Valonia microcrystals was achieved more slowly. Ultrastructural observations during the digestion process suggested that the rapid degradation of bacterial cellulose was the result of a very ecient synergistic action of the various enzymic components that are attached to the scaolding protein of the cellulosomes. The degraded Valonia sample assumed various shapes, ranging from thinned-down microcrystals to crystals where one end was pointed and the other intact. This complexity may be correlated
Junji Sugiyama - One of the best experts on this subject based on the ideXlab platform.
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accessibility and size of Valonia cellulose microfibril studied by combined deuteration rehydrogenation and ftir technique
Cellulose, 2008Co-Authors: Yoshiki Horikawa, Junji SugiyamaAbstract:We report an FTIR method to measure the accessibility and the size of cellulose microfibrils from the cell wall of Valonia ventricosa. This method is similar to the conventional deuteration technique for measuring the accessibility of cellulosic materials; however, the difference in our method is that the hydroxyl groups O2H, O3H, and O6H in the crystalline region were initially completely deuterated. The sample was then rehydrogenated by soaking in water at 25 °C, so that the OD groups on the surface were rehydrogenated. The ratio of OH to OD absorbance was used to calculate the number of surface vs. core cellulose chains in a microfibril. The obtained experimental ratio of 0.934 was consistent with the value calculated for a previously published 33 × 38 chain Valonia model (Sugiyama et al. 1984). The rehydrogenation process was further investigated by immersing the sample in water at elevated temperatures. At temperatures above 120 °C, rehydrogenation was more efficient, and the efficiency plots vs. rehydrogenation temperature showed two inflection. These points may correspond to the temperature where the cleavage of inter-chain hydrogen bonds and/or crystalline-phase transition would have been occurred.
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the binding specificity and affinity determinants of family 1 and family 3 cellulose binding modules
Proceedings of the National Academy of Sciences of the United States of America, 2003Co-Authors: Janne Lehtio, Junji Sugiyama, Malin Gustavsson, Linda Fransson, Markus Linder, Tuula T TeeriAbstract:Cellulose binding modules (CBMs) potentiate the action of cellulolytic enzymes on insoluble substrates. Numerous studies have established that three aromatic residues on a CBM surface are needed for binding onto cellulose crystals and that tryptophans contribute to higher binding affinity than tyrosines. However, studies addressing the nature of CBM–cellulose interactions have so far failed to establish the binding site on cellulose crystals targeted by CBMs. In this study, the binding sites of CBMs on Valonia cellulose crystals have been visualized by transmission electron microscopy. Fusion of the CBMs with a modified staphylococcal protein A (ZZ-domain) allowed direct immuno-gold labeling at close proximity of the actual CBM binding site. The transmission electron microscopy images provide unequivocal evidence that the fungal family 1 CBMs as well as the family 3 CBM from Clostridium thermocellum CipA have defined binding sites on two opposite corners of Valonia cellulose crystals. In most samples these corners are worn to display significant area of the hydrophobic (110) plane, which thus constitutes the binding site for these CBMs.
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unidirectional processive action of cellobiohydrolase cel7a on Valonia cellulose microcrystals
FEBS Letters, 1998Co-Authors: Tomoya Imai, Claire Boisset, Masahiro Samejima, Kiyohiko Igarashi, Junji SugiyamaAbstract:Abstract On the basis of the `parallel-up' structure of the cellulose crystal, a crystallographic approach to study the mode of action of cellobiohydrolase Cel7A on Valonia cellulose microcrystal has been carried out. After incubation with Cel7A, most of the initially smooth and well defined Valonia microcrystals displayed fibrillation. However, as the hydrolysis reaction was rather heterogeneous, some microcrystals remained superficially intact. Close investigation on such crystals revealed polar morphology: one end was narrowed extremely or pointed. Electron microdiffraction analysis of these crystals evidenced that the narrowing of the microcrystals occurs at their reducing end side. This was also confirmed by the visualization of selective reducing end labeling at the pointed ends of microcrystals. These lines of investigation are the first demonstration that the processivity of Cel7A action against insoluble highly crystalline celluloses is unambiguously toward non-reducing ends from reducing ends.
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the behaviour of phanerochaete chrysosporium cellobiose dehydrogenase on adsorption to crystallineand amorphous celluloses
Biotechnology and Applied Biochemistry, 1997Co-Authors: Takeshi Ohkubo, Akira Isogai, Shigenori Kuga, Junji SugiyamaAbstract:The adsorption of cellobiose dehydrogenase (CDH) to cellulose has been previously reported. However, the structural type of cellulose on to which CDH is adsorbed has not been investigated. In the present study we have compared the behaviour of CDH when it adsorbs on the highly crystalline cellulose microfibrils from Valonia macrophysa and on the completely amorphous cellulose prepared from a solution of Avicel in the So 2 /amine system. The isotherms of CDH adsorption to both Valonia and amorphous celluloses fit well with the Langmuir adsorption theory. However, the maximum adsorption of CDH to the amorphous cellulose was much higher than that to Valonia cellulose. The location of CDH adsorbed on cellulose was revealed with colloidal-gold-tagged antibodies by transmission electron microscopy. By using this technique it was demonstrated that CDH adsorption to Valonia cellulose was limited to the amorphous regions attached to the crystalline microfibrils, whereas no CDH was adsorbed to the surface of the highly crystalline microfibrils. Furthermore, continuous monitoring of cellulase activity showed that limited amounts of structures susceptible to enzymic hydrolysis exist even on the surface of Valonia cellulose. From these observations, we conclude that amorphous regions of cellulose seem to the preferred sites of CDH adsorption, whereas CDH is not adsorbed to the surface of highly crystalline microfibrils.
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High-Resolution Atomic Force Microscopy of Native Valonia Cellulose I Microcrystals
Journal of structural biology, 1997Co-Authors: Aa Baker, Junji Sugiyama, William Helbert, Mervyn J MilesAbstract:Abstract We have studied the surface of native Valonia cellulose I microcrystals under propanol and waterby atomic force microscopy (AFM). Ultra-high-resolution images of the surface are presented, as well as lower resolution morphological observations of whole crystals. The pitch of 0.52 nm along the molecule due to the asymmetrical glucose unit and the intermolecular spacing of ≈0.6 nm are clearly resolved in both imaging environments. The relationship between the crystalline bulk and the surface are discussed, with particular attention being paid to previous crystallographic studies. We also show that the glucose units along the cellulose chains are not topographically equivalent due to the twofold screw symmetry and accordingly present strong evidence of triclinic character by direct surface imaging, rather than by taking average measurements in reciprocal space. The crystallographic distinction between monoclinic and triclinic structure is a displacement of the cellulose chains by a quarter of the c axis period, resulting in either a stagger or a diagonal shifting, respectively, of the cellobiose unit along the chain axis by 0.26 nm. This structural identification (in real space) represents, as far as we are aware, the highest resolution AFM imaging of a biological specimen to date. This study opens up the future possibility of identifying the localized triclinic or monoclinic nature of the Valonia cellulose surface with AFM.
Claire Boisset - One of the best experts on this subject based on the ideXlab platform.
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Digestion of crystalline cellulose substrates by the clostridium thermocellum cellulosome: structural and morphological aspects.
The Biochemical journal, 1999Co-Authors: Claire Boisset, Henri Chanzy, Bernard Henrissat, Raphael Lamed, Yuval Shoham, E A BayerAbstract:The action of cellulosomes from Clostridium thermocellum on model cellulose microfibrils from Acetobacter xylinum and cellulose microcrystals from Valonia ventricosa was investigated. The biodegradation of these substrates was followed by transmission electron microscopy, Fourier-transform IR spectroscopy and X-ray diffraction analysis, as a function of the extent of degradation. The cellulosomes were very effective in catalysing the complete digestion of bacterial cellulose, but the total degradation of Valonia microcrystals was achieved more slowly. Ultrastructural observations during the digestion process suggested that the rapid degradation of bacterial cellulose was the result of a very efficient synergistic action of the various enzymic components that are attached to the scaffolding protein of the cellulosomes. The degraded Valonia sample assumed various shapes, ranging from thinned-down microcrystals to crystals where one end was pointed and the other intact. This complexity may be correlated with the multi-enzyme content of the cellulosomes and possibly to a diversity of the cellulosome composition within a given batch. Another aspect of the digestion of model celluloses by cellulosomes is the relative invariability of their crystallinity, together with their Ialpha/Ibeta composition throughout the degradation process. Comparison of the action of cellulosomes with that of fungal enzymes indicated that the degradation of cellulose crystals by cellulosomes occurred with only limited levels of processivity, in contrast with the observations reported for fungal enzymes. The findings were consistent with a mechanism whereby initial attack by a cellulosome of an individual cellulose crystal results in its 'commitment' towards complete degradation.
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digestion of crystalline cellulose substrates by the clostridium thermocellum cellulosome structural and morphological aspects
Biochemical Journal, 1999Co-Authors: Claire Boisset, Henri Chanzy, Bernard Henrissat, Raphael Lamed, Yuval Shoham, E A BayerAbstract:The action of cellulosomes from Clostridium thermocellum on model cellulose microfibrils from Acetobacter xylinum and cellulose microcrystals from Valonia aentricosa was investigated. The biodegradation of these substrates was followed by transmission electron microscopy, Fourier-transform IR spectroscopy and Xray diraction analysis, as a function of the extent of degradation. The cellulosomes were very eective in catalysing the complete digestion of bacterial cellulose, but the total degradation of Valonia microcrystals was achieved more slowly. Ultrastructural observations during the digestion process suggested that the rapid degradation of bacterial cellulose was the result of a very ecient synergistic action of the various enzymic components that are attached to the scaolding protein of the cellulosomes. The degraded Valonia sample assumed various shapes, ranging from thinned-down microcrystals to crystals where one end was pointed and the other intact. This complexity may be correlated
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unidirectional processive action of cellobiohydrolase cel7a on Valonia cellulose microcrystals
FEBS Letters, 1998Co-Authors: Tomoya Imai, Claire Boisset, Masahiro Samejima, Kiyohiko Igarashi, Junji SugiyamaAbstract:Abstract On the basis of the `parallel-up' structure of the cellulose crystal, a crystallographic approach to study the mode of action of cellobiohydrolase Cel7A on Valonia cellulose microcrystal has been carried out. After incubation with Cel7A, most of the initially smooth and well defined Valonia microcrystals displayed fibrillation. However, as the hydrolysis reaction was rather heterogeneous, some microcrystals remained superficially intact. Close investigation on such crystals revealed polar morphology: one end was narrowed extremely or pointed. Electron microdiffraction analysis of these crystals evidenced that the narrowing of the microcrystals occurs at their reducing end side. This was also confirmed by the visualization of selective reducing end labeling at the pointed ends of microcrystals. These lines of investigation are the first demonstration that the processivity of Cel7A action against insoluble highly crystalline celluloses is unambiguously toward non-reducing ends from reducing ends.
Colodro Sainz Itziar - One of the best experts on this subject based on the ideXlab platform.
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El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote)
'Universitat Politecnica de Valencia', 2014Co-Authors: Colodro Sainz ItziarAbstract:El creciente urbanismo en zonas costeras, la contaminación marina y la explotación de los recursos han provocado, entre otras consecuencias, la eutrofización de las aguas. El Charco de San Ginés (Arrecife, Lanzarote) es un ecosistema singular sometido a lo largo de la historia a la presión antrópica devaluando su estado ecológico. En la actualidad, han proliferado unas bolas de algas, predominantemente Valonia aegagropila. En este contexto, se pretende realizar un estudio sobre el efecto depurativo que puedan tener estas bolas en la aguas del Charco de San Ginés. Para ello, el proyecto consiste en tres ensayos “ex situ”, que consistirán en la preparación de cilindros llenos de agua del Charco de San Ginés de un punto previamente seleccionado, unos con una bola de Valonia y otros, sin ninguna bola a modo de Control. Se realizarán extracciones periódicas aproximadamente a diferentes horas del día tanto de dentro como de fuera de la bola y así medir los nutrientes analíticamente. Se controlará el oxígeno disuelto, pH y temperatura. Los resultados obtenidos mostraron que según las dimensiones de cada bola y su relación con agua a tratar se pueden observar o no diferencias significativas en los tratamientos aplicabes para valorar su efecto como biofiltro en aguas marinas.The increasing urbanization in coastal areas, marine pollution and resource exploitation have led, among other consequences, the water eutrophication. El Charco de San Ginés (Arrecife, Lanzarote) is a unique ecosystem, under throughout history to human pressure devaluing its ecological status. Currently, they have proliferated balls of algae, predominantly Valonia aegagropila. In this context, we will do a study for evaluate the effect that may have these balls in the waters of the Charco de San Ginés. For this, the project consists of three "ex situ" tests, which include the preparation of cylinders whith water of a previously selected point in the Charco de San Ginés, some, with a ball of Valonia and others, without any ball as a Control. Periodic withdrawals will be made about different times of day both inside and outside the ball and thus measure the nutrients analytically. Dissolved oxygen, pH and temperature will be controlerl. The results showed that as the size of each ball and its relationship with water to be treated can be observed, signifcant or no significant differences in the treatments aplicabes to assess their effect as biofilter in seawater.Colodro Sainz, I. (2014). El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote). Universitat Politècnica de València. http://hdl.handle.net/10251/45137Archivo delegad
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El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote)
'Universitat Politecnica de Valencia', 2014Co-Authors: Colodro Sainz ItziarAbstract:El creciente urbanismo en zonas costeras, la contaminación marina y la explotación de los recursos han provocado, entre otras consecuencias, la eutrofización de las aguas. El Charco de San Ginés (Arrecife, Lanzarote) es un ecosistema singular sometido a lo largo de la historia a la presión antrópica devaluando su estado ecológico. En la actualidad, han proliferado unas bolas de algas, predominantemente Valonia aegagropila. En este contexto, se pretende realizar un estudio sobre el efecto depurativo que puedan tener estas bolas en la aguas del Charco de San Ginés. Para ello, el proyecto consiste en tres ensayos “ex situ”, que consistirán en la preparación de cilindros llenos de agua del Charco de San Ginés de un punto previamente seleccionado, unos con una bola de Valonia y otros, sin ninguna bola a modo de Control. Se realizarán extracciones periódicas aproximadamente a diferentes horas del día tanto de dentro como de fuera de la bola y así medir los nutrientes analíticamente. Se controlará el oxígeno disuelto, pH y temperatura. Los resultados obtenidos mostraron que según las dimensiones de cada bola y su relación con agua a tratar se pueden observar o no diferencias significativas en los tratamientos aplicabes para valorar su efecto como biofiltro en aguas marinas.The increasing urbanization in coastal areas, marine pollution and resource exploitation have led, among other consequences, the water eutrophication. El Charco de San Ginés (Arrecife, Lanzarote) is a unique ecosystem, under throughout history to human pressure devaluing its ecological status. Currently, they have proliferated balls of algae, predominantly Valonia aegagropila. In this context, we will do a study for evaluate the effect that may have these balls in the waters of the Charco de San Ginés. For this, the project consists of three "ex situ" tests, which include the preparation of cylinders whith water of a previously selected point in the Charco de San Ginés, some, with a ball of Valonia and others, without any ball as a Control. Periodic withdrawals will be made about different times of day both inside and outside the ball and thus measure the nutrients analytically. Dissolved oxygen, pH and temperature will be controlerl. The results showed that as the size of each ball and its relationship with water to be treated can be observed, signifcant or no significant differences in the treatments aplicabes to assess their effect as biofilter in seawater.Colodro Sainz, I. (2014). El papel de las 'bolas de Valonia' en la depuración de las aguas del Charco de San Ginés, Arrecife (Lanzarote). http://hdl.handle.net/10251/45137Archivo delegad
Yalçın Mesut - One of the best experts on this subject based on the ideXlab platform.
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Utilizing the Wastes of Valonia Oak (Quercus ithaburensis Decne subsp macrolepis) in Pleurotus ostreatus Production
'Cevre Koruma ve Arastirma Vakfi', 2011Co-Authors: Şen Selim, Yalçın MesutAbstract:WOS: 000291232900010In this study, utilizing the wastes of Valonia oak (Quercus ithaburensis Decne subsp macrolepis) in P ostreatus cultivation is investigated. The tannin obtained from Valonia oak mostly utilized in leather industry. After having been extracted for tannin, the waste has no industrial utilization yet in Turkey. Milled Valonia oak wastes composed of acorn cup held high humidity; therefore, has high drying cost for transporting as well as storage problems of the mills. Valonia oak wastes were used as compost to cultivate P streams. Results indicated that the mycelia development on oak wastes were realized 45 days yield of 24.5% (weight/weight) which is to be considered as potential substrate for P ostreatus cultivation
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Utilizing the wastes of Valonia oak (Quercus ithaburensis Decne subsp macrolepis) in pleurotus ostreatus production
2011Co-Authors: Şen Selim, Yalçın MesutAbstract:Bu çalışma deri sanayisinin önemli hammaddelerinden biri olan me?e palamudunun (Quercus ithaburensis Decne subsp macrolepis) tanen üretiminde değerlendirildikten sonra açığa çıkan atık materyalin Pleurotus ostreatus mantarının üretiminde kullanım durumunun belirlenmesi amacıyla yapılmıştır. Ortaya çıkan atık, içerdiği nem miktarının yüksek olması, kurutma maliyetleri ve nakliye masraflarından dolayı değerlendirilemeyerek işletmelerin sahalarında birikerek, geniş yer işgal etmektedir. Atık olarak temin edilen materyalin kimyasal analizi yapılarak lignoselülozik ortamda yetişen P. ostreatus mantarı üretimi için kompostlar hazırlanmıştır. Misel oluşum süresi 45 gün, mantar verimi %24,5 (yaş ağırlık/taze ağırlık) olarak gerçekleşmiştir. Çalışmanın sonucunda meşe palamudu atıklarının bu mantarın yetiştirilmesinde kompost olarak kullanılabileceği belirlenmiştir.In this study, utilizing the wastes of Valonia oak (Quercus ithaburensis Decne subsp macrolepis) in P. ostreatus cultivation is investigated. The tannin obtained from Valonia oak mostly utilized in leather industry. After having been extracted for tannin, the waste has no industrial utilization yet in Turkey. Milled Valonia oak wastes composed of acorn cup held high humidity; therefore, has high drying cost for transporting as well as storage problems of the mills. Valonia oak wastes were used as compost to cultivate P. ostreatus. Results indicated that the mycelia development on oak wastes were realized 45 days yield of 24.5% (weight/weight) which is to be considered as potential substrate for P. ostreatus cultivation
