Surface area of pretreated lignocellulosics as a function of the extent of enzymatic hydrolysis

1989 ◽  
Vol 20-21 (1) ◽  
pp. 79-94 ◽  
Author(s):  
D. S. Burns ◽  
H. Ooshima ◽  
A. O. Converse
Keyword(s):  
Enzymatic Hydrolysis ◽  
Surface Area ◽  
Pretreated Lignocellulosics

scholarly journals Organosolv pretreatment assisted by carbocation scavenger to mitigate surface barrier effect of lignin for improving biomass saccharification and utilization

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Qiulu Chu ◽  
Wenyao Tong ◽  
Jianqiang Chen ◽  
Shufang Wu ◽  
Yongcan Jin ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Surface Area ◽  
Cellulose Hydrolysis ◽  
Syringic Acid ◽  
Fermentable Sugars ◽  
Surface Barrier ◽  
Textile Dye ◽  
Barrier Effect ◽  
Biomass Saccharification ◽  
Carbocation Scavenger

Abstract Background Ethanol organosolv (EOS) pretreatment is one of the most efficient methods for boosting biomass saccharification as it can achieve an efficient fractionation of three major constituents in lignocellulose. However, lignin repolymerization often occurs in acid EOS pretreatment, which impairs subsequent enzymatic hydrolysis. This study investigated acid EOS pretreatment assisted by carbocation scavenger (2-naphthol, 2-naphthol-7-sulfonate, mannitol and syringic acid) to improve biomass fractionation, coproduction of fermentable sugars and lignin adsorbents. In addition, surface barrier effect of lignin on cellulose hydrolysis was isolated from unproductive binding effect of lignin, and the analyses of surface chemistry, surface morphology and surface area were carried out to reveal the lignin inhibition mitigating effect of various additives. Results Four different additives all helped mitigate lignin inhibition on cellulose hydrolysis in particular diminishing surface barrier effect, among which 2-naphthol-7-sulfonate showed the best performance in improving pretreatment efficacy, while mannitol and syringic acid could serve as novel green additives. Through the addition of 2-naphthol-7-sulfonate, selective lignin removal was increased up to 76%, while cellulose hydrolysis yield was improved by 85%. As a result, 35.78 kg cellulose and 16.63 kg hemicellulose from 100 kg poplar could be released and recovered as fermentable sugars, corresponding to a sugar yield of 78%. Moreover, 22.56 kg ethanol organosolv lignin and 17.53 kg enzymatic hydrolysis residue could be recovered as lignin adsorbents for textile dye removal, with the adsorption capacities of 45.87 and 103.09 mg g−1, respectively. Conclusions Results in this work indicated proper additives could give rise to the form of less repolymerized surface lignin, which would decrease the unproductive binding of cellulase enzymes to surface lignin. Besides, the supplementation of additives (NS, MT and SA) resulted in a simultaneously increased surface area and decreased lignin coverage. All these factors contributed to the diminished surface barrier effect of lignin, thereby improving the ease of enzymatic hydrolysis of cellulose. The biorefinery process based on acidic EOS pretreatment assisted by carbocation scavenger was proved to enable the coproduction of fermentable sugars and lignin adsorbents, allowing the holistic utilization of lignocellulosic biomass for a sustainable biorefinery. Graphic abstract

scholarly journals Determination of Surface Accessibility of the Cellulose Substrate According to Enzyme Sorption

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1201 ◽  
Author(s):  
Ekaterina M. Podgorbunskikh ◽  
Aleksey L. Bychkov ◽  
Oleg I. Lomovsky
Keyword(s):  
Enzymatic Hydrolysis ◽  
Mechanical Activation ◽  
Surface Area ◽  
Initial Rate ◽  
Plant Biomass ◽  
Inorganic Compounds ◽  
Cellulolytic Enzymes ◽  
Surface Accessibility ◽  
Cellulose Substrate ◽  
Rate Of Hydrolysis

As a heterogeneous process, enzymatic hydrolysis depends on the contact area between enzymes and the cellulose substrate. The surface area of a substrate is typically evaluated through the sorption of gases (nitrogen, argon, or water vapor) or sorption of high-molecular-weight pigments or proteins. However, lignocellulosic biomass uninvolved in the reaction because of inefficient binding or even the complete inhibition of the enzymes on the surface consisting of lignin or inorganic compounds is erroneously taken into account under these conditions. The initial rate of enzymatic hydrolysis will directly depend on the number of enzymes efficiently sorbed onto cellulose. In this study, the sorption of cellulolytic enzymes was used to evaluate the surface accessibility of the cellulose substrate and its changes during mechanical pretreatment. It was demonstrated that for pure cellulose, mechanical activation did not alter the chemical composition of the surface and the initial rate of hydrolysis increased, which was inconsistent with the data on the thermal desorption of nitrogen. New active cellulose sorption sites were shown to be formed upon. the mechanical activation of plant biomass (wheat straw), and the ultimate initial rate of hydrolysis corresponding to saturation of the accessible surface area with enzyme molecules was determined.

scholarly journals Reduction of surface area of lignin improves enzymatic hydrolysis of cellulose from hydrothermally pretreated wheat straw

RSC Advances ◽  
2014 ◽  
Vol 4 (69) ◽  
pp. 36591-36596 ◽  
Author(s):  
M. H. Sipponen ◽  
V. Pihlajaniemi ◽  
O. Pastinen ◽  
S. Laakso
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Surface Area ◽  
Lignin Content ◽  
Cellulose Conversion ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Pretreated Wheat Straw ◽  
Hydrolysis Of

24 h enzymatic hydrolysis (15 FPU g−1) of solid residues from wheat straw autohydrolysis. Cellulose conversion as a function of lignin content (left) or lignin surface area (right) in solid residues.

Xyloglucan adsorption for measuring the specific surface area on various never-dried cellulose nanofibers

2018 ◽  
Vol 33 (2) ◽  
pp. 186-193 ◽  
Author(s):  
Carl Moser ◽  
Hanéle Backlund ◽  
Louise Drenth ◽  
Gunnar Henriksson ◽  
Mikael E. Lindström
Keyword(s):  
Ionic Strength ◽  
Enzymatic Hydrolysis ◽  
Surface Area ◽  
Cellulose Nanofibers ◽  
Accessible Surface Area ◽  
Surface Areas ◽  
Accessible Surface ◽  
Low Ionic Strength ◽  
Cellulose Surface ◽  
Mediated Oxidation

Abstract In this paper, we explore xyloglucan adsorption to cellulose nanofibers as a method for the evaluation of their quality (i. e., the degree of disintegration) and the accessible surface area in the wet state and at low ionic strength. This method was shown to be capable of estimating the surface areas of 14 different cellulose nanofiber qualities from both hardwood and softwood with different pretreatments, including enzymatic hydrolysis using a monocomponent endoglucanase, TEMPO-mediated oxidation, and carboxymethylation. The cellulose surface measured using this method showed a correlation with the degree of disintegration expressed as transmittance for different concentrations of xyloglucan.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Cell morphology, volume, and surface area determinations from multilevel contouring within HVEM micrographs of serial sections and whole-cell mounts

1987 ◽  
Vol 45 ◽  
pp. 588-589
Author(s):  
M. Marko ◽  
A. Leith ◽  
D. Parsons
Keyword(s):  
Surface Area ◽  
Electron Micrographs ◽  
Cell Morphology ◽  
Individual Variation ◽  
Serial Section ◽  
Stereo Pair ◽  
Complex Structures ◽  
Serial Sections ◽  
Surface Areas ◽  
Computer Based

The use of serial sections and computer-based 3-D reconstruction techniques affords an opportunity not only to visualize the shape and distribution of the structures being studied, but also to determine their volumes and surface areas. Up until now, this has been done using serial ultrathin sections.The serial-section approach differs from the stereo logical methods of Weibel in that it is based on the Information from a set of single, complete cells (or organelles) rather than on a random 2-dimensional sampling of a population of cells. Because of this, it can more easily provide absolute values of volume and surface area, especially for highly-complex structures. It also allows study of individual variation among the cells, and study of structures which occur only infrequently.We have developed a system for 3-D reconstruction of objects from stereo-pair electron micrographs of thick specimens.

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