Cellulolytic enzymes behavior in delignified green coconut residues and enzymatic hydrolysis with enzyme recovery

2021 ◽  
Vol 172 ◽  
pp. 114037
Author(s):  
Petrúcia Karine Santos de Brito Bezerra ◽  
Otávio Lima da Silva ◽  
Sérgio Dantas de Oliveira Júnior ◽  
Carlos Eduardo de Araújo Padilha ◽  
Everaldo Silvino dos Santos
Keyword(s):  
Enzymatic Hydrolysis ◽  
Cellulolytic Enzymes ◽  
Enzyme Recovery

scholarly journals Generation of highly amenable cellulose-Iβ via selective delignification of rice straw using a reusable cyclic ether-assisted deep eutectic solvent system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chiranjeevi Thulluri ◽  
Ravi Balasubramaniam ◽  
Harshad Ravindra Velankar
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Deep Eutectic Solvent ◽  
Solvent System ◽  
Cyclic Ether ◽  
Cellulolytic Enzymes ◽  
Ammonium Bromide ◽  
Selective Delignification ◽  
Cellulose Iβ ◽  
Hydrolysis Of

AbstractCellulolytic enzymes can readily access the cellulosic component of lignocellulosic biomass after the removal of lignin during biomass pretreatment. The enzymatic hydrolysis of cellulose is necessary for generating monomeric sugars, which are then fermented into ethanol. In our study, a combination of a deep eutectic (DE) mixture (of 2-aminoethanol and tetra-n-butyl ammonium bromide) and a cyclic ether (tetrahydrofuran) was used for selective delignification of rice straw (RS) under mild conditions (100 °C). Pretreatment with DE-THF solvent system caused ~ 46% delignification whereas cellulose (~ 91%) and hemicellulose (~ 67%) recoveries remained higher. The new solvent system could be reused upto 10 subsequent cycles with the same effectivity. Interestingly, the DE-THF pretreated cellulose showed remarkable enzymatic hydrolysability, despite an increase in its crystallinity to 72.3%. Contrary to conventional pretreatments, we report for the first time that the enzymatic hydrolysis of pretreated cellulose is enhanced by the removal of lignin during DE-THF pretreatment, notwithstanding an increase in its crystallinity. The current study paves way for the development of newer strategies for biomass depolymerization with DES based solvents.

scholarly journals Accumulation of dry substances in hydrolysate during the processing of barley malt sprouts with a celluloid enzyme complex

2021 ◽  
Vol 32 ◽  
pp. 03005
Author(s):  
O. N. Vetrova ◽  
O. Y. Eremina ◽  
N. V. Seregina ◽  
N. V. Shuldeshova
Keyword(s):  
Enzymatic Hydrolysis ◽  
Substrate Concentration ◽  
Enzyme Preparation ◽  
Mutual Influence ◽  
Matter Content ◽  
Cellulolytic Enzymes ◽  
Dry Matter Content ◽  
Barley Malt ◽  
Hydrolysis Process ◽  
Parameter Values

The article presents the results of a study of the enzymatic hydrolysis of barley malt sprouts by cellulolytic enzymes. The influence of the process parameters (temperature, substrate concentration, concentration of the enzyme preparation, duration of the process) on the output of dry substances in the hydrolysate is shown. The results of the experiments were presented by a mathematical model of the process and graphically-in the form of surface projections reflecting the mutual influence of each possible pair of factors on the dry matter content in the hydrolysate. It is found that all the studied factors have an effect on the accumulation of dry substances in the hydrolysate. As a result of optimization the parameters of the enzymatic hydrolysis process, the following parameter values were obtained: temperature - 50 ˚С, duration of enzymatic hydrolysis-89 min, substrate concentration - 0.37 (hydromodule 1:10), concentration of the enzyme preparation - 0.05 %.

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 Enzymatic hydrolysis and fermentation strategies for the biorefining of pine sawdust

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7474-7491
Author(s):  
Carolina Mónica Mendieta ◽  
Fernando Esteban Felissia ◽  
Ana María Arismendy ◽  
Julia Kruyeniski ◽  
María Cristina Area
Keyword(s):  
Enzymatic Hydrolysis ◽  
Simultaneous Saccharification And Fermentation ◽  
Design Tool ◽  
Cellulolytic Enzymes ◽  
Chemical Compositions ◽  
Pine Sawdust ◽  
Second Generation Bioethanol ◽  
Separate Hydrolysis And Fermentation ◽  
Experimental Values ◽  
Simultaneous Saccharification

This work aims to evaluate second-generation bioethanol production from the soda-ethanol pulp of pine sawdust via two strategies: separate hydrolysis and fermentation and simultaneous saccharification and fermentation. A kinetics study of the enzymatic hydrolysis of separate hydrolysis and fermentation was included as a design tool. Three soda-ethanol pulps (with different chemical compositions), Cellic® Ctec2 cellulolytic enzymes, and Saccharomyces cerevisiae IMR 1181 (SC 1181) yeast were employed. The obtained kinetic parameters were as follows: an apparent constant (k) of 11.4 h-1, which represents the link frequency between cellulose and cellulase; a Michaelis-Menten apparent constant (KM) of 23.5 gL-1, that indicates the cellulose/cellulase affinity; and the apparent constant of inhibition between cellulose-glucose and cellulase (KI), which was 2.9 gL-1, 3.1 gL-1, and 6.6 gL-1 for pulps 1, 2, and 3, respectively. The kinetic model was applicable, since the calculated glucose values fit the experimental values. High bioethanol yields were obtained for pulp 3 in the separate hydrolysis and fermentation and simultaneous saccharification and fermentation processes (89.3% and 100% after 13 h and 72 h, respectively).

scholarly journals Optimization ofArundo donaxSaccharification by (Hemi)cellulolytic Enzymes fromPleurotus ostreatus

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Rossana Liguori ◽  
Elena Ionata ◽  
Loredana Marcolongo ◽  
Luciana Porto de Souza Vandenberghe ◽  
Francesco La Cara ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Experimental Design ◽  
Enzymatic Hydrolysis ◽  
Microcrystalline Cellulose ◽  
Significant Influence ◽  
Cellulolytic Enzymes ◽  
Factorial Experimental Design ◽  
Screening Design ◽  
Commercial Enzymes ◽  
Hydrolysis Of

An enzymatic mixture of cellulases and xylanases was produced byPleurotus ostreatususing microcrystalline cellulose as inducer, partially characterized and tested in the statistical analysis ofArundo donaxbioconversion. The Plackett-Burman screening design was applied to identify the most significant parameters for the enzymatic hydrolysis of pretreatedA. donax. As the most significant influence during the enzymatic hydrolysis ofA. donaxwas exercised by the temperature (°C), pH, and time, the combined effect of these factors in the bioconversion byP. ostreatuscellulase and xylanase was analyzed by a 33factorial experimental design. It is worth noting that the best result of 480.10 mg of sugars/gds, obtained at 45°C, pH 3.5, and 96 hours of incubation, was significant also when compared with the results previously reached by process optimization with commercial enzymes.

scholarly journals Biological Pretreatment of Corn Stover for Enhancing Enzymatic Hydrolysis Using Thermoalkalotolerant Cellulolytic Enzymes Produced by Bacillus sp. P3

2021 ◽  
Author(s):  
Yanwen Wu ◽  
Haipeng Guo ◽  
Md. Shafiqur Rahman ◽  
Xuantong Chen ◽  
Jinchi Zhang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Fermentation Broth ◽  
Removal Rate ◽  
Enzymatic Saccharification ◽  
Cellulolytic Enzymes ◽  
Biological Pretreatment ◽  
Hydrolysis Process ◽  
Hemicellulose Removal ◽  
Hydrolysis Of

Abstract The biological pretreatment for the enzymatic hydrolysis of lignocellulosic biomasses largely depends on an effective pretreatment process. A significant enhancement of enzymatic saccharification was obtained with corn stover using Bacillus sp. P3. The hemicellulose removal from corn stover by the strain Bacillus sp. P3 was evaluated for enhancing subsequent enzymatic hydrolysis. Therefore, our study revealed that an alkaline resistant xylanase produced by Bacillus sp. P3 in fermentation broth led to a substantially enhanced hemicellulose removal rate from corn stover within pH 9.36–9.68. However, after 20 d pretreatment of corn stover by the strain P3, the glucan content was increased by 51% and the xylan content was decreased by 35%. After 72 h of saccharification using 20 U g− 1 of commercial cellulase, the yield of reducing sugar released from 20 d pretreated corn stover was increased by 56% in comparison to the untreated corn stover. Therefore, the use of the strain P3 could be a promising approach to pretreat corn stover for enhancing the enzymatic hydrolysis process of industrial bioenergy productions.

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