scholarly journals One-Step or Two-Step Acid/Alkaline Pretreatments to Improve Enzymatic Hydrolysis and Sugar Recovery from Arundo Donax L.

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 948
Author(s):  
Shangyuan Tang ◽  
Yushen Cao ◽  
Chunming Xu ◽  
Yue Wu ◽  
Lingci Li ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ferric Chloride ◽  
Soluble Sugars ◽  
Arundo Donax ◽  
Sugar Yield ◽  
Alkaline Pretreatment ◽  
Biofuel Production ◽  
Hydrolysis Process ◽  
Morphological Modification ◽  
Arundo Donax L

Energy crops are not easily converted by microorganisms because of their recalcitrance. This necessitates a pretreatment to improve their biodigestibility. The effects of different pretreatments, as well as their combination on the enzymatic digestibility of Arundo donax L. were systematically investigated to evaluate its potential for bioconversion. Dilute alkaline pretreatment (ALP) using 1.2% NaOH at 120 °C for 30 min resulted in the highest reducing sugar yield in the enzymatic hydrolysis process because of its strong delignification and morphological modification, while ferric chloride pretreatment (FP) was effective in removing hemicellulose and recovering soluble sugars in the pretreatment stage. Furthermore, an efficient two-step ferric chloride-alkaline pretreatment (FALP) was successfully developed. In the first FP step, easily degradable cellulosic components, especially hemicellulose, were dissolved and then effectively recovered as soluble sugars. Subsequently, the FP sample was further treated in the second ALP step to remove lignin to enhance the enzymatic hydrolysis of the hardly degradable cellulose. As a result, the integrated two-step process obtained the highest total sugar yield of 420.4 mg/g raw stalk in the whole pretreatment and enzymatic hydrolysis process; hence, the process is a valuable candidate for biofuel production.

scholarly journals A Two-Step Ferric Chloride and Dilute Alkaline Pretreatment for Enhancing Enzymatic Hydrolysis and Fermentable Sugar Recovery from Miscanthus sinensis

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1843
Author(s):  
Lingci Li ◽  
Peng Ye ◽  
Mengyu Chen ◽  
Shangyuan Tang ◽  
Ying Luo ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ferric Chloride ◽  
Morphological Changes ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Alkaline Pretreatment ◽  
Miscanthus Sinensis ◽  
Sugar Recovery ◽  
Step Process ◽  
Whole Process

A two-step process was proposed to enhance enzymatic hydrolysis of Miscanthus sinensis based on a comparative study of acid/alkaline pretreatments. Ferric chloride pretreatment (FP) effectively removed hemicellulose and recovered soluble sugars, but the enzymatic hydrolysis was not efficient. Dilute alkaline pretreatment (ALP) resulted in much better delignification and stronger morphological changes of the sample, making it more accessible to enzymes. While ALP obtained the highest sugar yield during enzymatic hydrolysis, the soluble sugar recovery from the pretreatment stage was still limited. Furthermore, a two-step ferric chloride and dilute alkaline pretreatment (F-ALP) has been successfully developed by effectively recovering soluble sugars in the first FP step and further removing lignin of the FP sample in the second ALP step to improve its enzymatic hydrolysis. As a result, the two-step process yielded the highest total sugar recovery (418.8 mg/g raw stalk) through the whole process.

scholarly journals Enhancing Enzymatic Digestibility of Coconut Husk using Nitrogen-assisted Subcritical Water for Sugar Production

2019 ◽  
Vol 15 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Maktum Muharja ◽  
Nur Fadhilah ◽  
Tantular Nurtono ◽  
Arief Widjaja
Keyword(s):  
Enzymatic Hydrolysis ◽  
Subcritical Water ◽  
Agricultural Waste ◽  
Biofuel Production ◽  
Sugar Production ◽  
Operation Condition ◽  
Coconut Husk ◽  
Commercial Scale ◽  
Hydrolysis Process ◽  
Hydrolysis Of

Coconut husk (CCH) as an abundant agricultural waste in Indonesia has the potential to be utilized for sugar production, which is the intermediate product of biofuel. In this study, subcritical water (SCW) assisted by nitrogen (N2) was developed to enhance the enzymatic hydrolysis of CCH. SCW process was optimized by varying the operation condition: the pressure of 60-100 bar, the temperature of 150-190 °C, and the time of 20-60 min. The SCW-treated solid was subsequently hydrolyzed by utilizing a mixture of commercial cellulase and xylanase enzymes. The result shows that the optimum total sugar yield was obtained under the mild condition of SCW treatment, resulting in the sugar of 15.67 % and 10.31 % gained after SCW and enzymatic hydrolysis process, respectively. SEM and FTIR analysis of SCW-treated solid exhibited the deformation of lignin and solubilization of cellulose and hemicellulose, while XRD and TGA revealed an increase of the amount of crystalline part in the solid residue. The use of N2 in SCW treatment combined with enzymatic hydrolysis in this study suggested that the method can be considered economically for biofuel production from CCH waste in commercial scale. Copyright © 2020 BCREC Group. All rights reserved 

Effects of Particle Size on Biomass Pretreatment for Biofuel Production

2019 ◽  
Author(s):  
Yang Yang ◽  
Mingman Sun ◽  
Timothy Deines ◽  
Meng Zhang ◽  
Jun Li ◽  
...  
Keyword(s):  
Particle Size ◽  
Enzymatic Hydrolysis ◽  
Dry Weight ◽  
Sugar Yield ◽  
Biofuel Production ◽  
Biomass Pretreatment ◽  
Current Status ◽  
Biomass Structure ◽  
Before And After ◽  
Biomass Particle Size

Abstract Biofuel production needs to be more efficient than its current status to increase its competitiveness. The multistep biofuel production is consisted of processes on biomass preprocessing and bioconversion stages. As a crucial parameter, biomass particle size has significant effects on both stages. It is essential to have an insightful understanding of the effects of particle size on sugar yield. Although numerous studies have been performed to meet this objective, there is no commonly accepted guideline on how to select particle size. One possible reason for this gap is the effects of particle size vary when different biomass pretreatment methods are employed. In this study, an assessment on the relationship between particle size and sugar yield was performed for four pretreatment methods. Three particle sizes (1, 4, and 8 mm) of corn stover and switchgrass biomass were used in supercritical CO2, dilute acid (H2SO4), dilute alkaline (Na2CO3), and metal oxide (MgO) pretreatments. Biomass compositional analyses were conducted before and after each pretreatment. Pretreatment solid recovery and sugar recovery rates were calculated. Enzymatic hydrolysis sugar yield and efficiency were used to evaluate the performance of hydrolysis and total sugar yield was used to interpret how much sugar a unit dry weight of biomass (before pretreatment) can yield through pretreatment and enzymatic hydrolysis combined. It was found that particle size was a weak indicator of enzymatic hydrolysis efficiency. There was little value in reducing particle size below 8 mm in order to overcome the resistance imposed by biomass structure on cellulose and xylan hydrolysis.

scholarly journals Pretreatment of sweet sorghum straw and its enzymatic digestion: insight into the structural changes and visualization of hydrolysis process

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Miaoyin Dong ◽  
Shuyang Wang ◽  
Fuqiang Xu ◽  
Junkai Wang ◽  
Ning Yang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Cell Walls ◽  
Sweet Sorghum ◽  
Enzymatic Digestion ◽  
Fluorescent Labeling ◽  
Biofuel Production ◽  
Vascular Bundles ◽  
Hydrolysis Process ◽  
Sorghum Straw

Abstract Background The efficient utilization of lignocellulosic biomass for biofuel production has received increasing attention. Previous studies have investigated the pretreatment process of biomass, but the detailed enzymatic hydrolysis process of pretreated biomass remains largely unclear. Thus, this study investigated the pretreatment efficiency of dilute alkali, acid, hydrogen peroxide and its ultimate effects on enzymatic hydrolysis. Furthermore, to better understand the enzymatic digestion process of alkali-pretreated sweet sorghum straw (SSS), multimodal microscopy techniques were used to visualize the enzymatic hydrolysis process. Result After pretreatment with alkali, an enzymatic hydrolysis efficiency of 86.44% was obtained, which increased by 99.54% compared to the untreated straw (43.23%). The FTIR, XRD and SEM characterization revealed a sequence of microstructural changes occurring in plant cell walls after pretreatment, including the destruction of lignin–polysaccharide interactions, the increase of porosity and crystallinity, and reduction of recalcitrance. During the course of hydrolysis, the cellulase dissolved the cell walls in the same manner and the digestion firstly occurred from the middle of cell walls and then toward the cell wall corners. The CLSM coupled with fluorescent labeling demonstrated that the sclerenchyma cells and vascular bundles in natural SSS were highly lignified, which caused the nonproductive bindings of cellulase on lignin. However, the efficient delignification significantly increased the accessibility and digestibility of cellulase to biomass, thereby improving the saccharification efficiency. Conclusion This work will be helpful in investigating the biomass pretreatment and its structural characterization. In addition, the visualization results of the enzymatic hydrolysis process of pretreated lignocellulose could be used for guidance to explore the lignocellulosic biomass processing and large-scale biofuel production.

Acid-Alkaline Two-Stage Pretreatments of Corn Stover for Enhancing Enzymatic Saccharification

2013 ◽  
Vol 724-725 ◽  
pp. 207-211 ◽  
Author(s):  
Hai Song Wang ◽  
Hong Ling Gao ◽  
Bin Li ◽  
Xin Dong Mu
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Lignocellulosic Biomass ◽  
Enzymatic Saccharification ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
Alkaline Pretreatment ◽  
Two Stage ◽  
Glucose Yield ◽  
Second Stage

For the enzymatic saccharification of lignocellulosic biomass, single acid or alkaline pretreatment is not satisfactory because of the low sugar yields together with the neutralization of residual chemicals before enzymatic hydrolysis. Herein, an acid-alkaline two-stage pretreatment process was designed to treat corn stover. During the process, the pretreated liquid from the first stage and the solid residues from the second stage were mixed together for the subsequent simultaneous enzymatic hydrolysis, where a mixture of cellulase with an activity loading of 20 FPU/g substrate, cellobiase with an activity loading of 5 U/g substrate, and xylanase with an activity loading of 200 U/g substrate was used. Compared to the single acid or alkaline pretreatment, the acid-alkaline two-stage pretreatment could significantly improve the enzymatic saccharification, and 91.2% glucose yield with 52.56% of the theoretical total reducing sugar yield was achieved after the subsequent enzymatic hydrolysis.

scholarly journals Enhanced Enzymatic Hydrolysis of Pennisetum alopecuroides by Dilute Acid, Alkaline and Ferric Chloride Pretreatments

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1715 ◽  
Author(s):  
Shangyuan Tang ◽  
Chunming Xu ◽  
Linh Tran Khanh Vu ◽  
Sicheng Liu ◽  
Peng Ye ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ferric Chloride ◽  
Morphological Changes ◽  
Soluble Sugar ◽  
Dilute Acid Pretreatment ◽  
Biofuel Production ◽  
Dilute Acid ◽  
Acid Pretreatment ◽  
Total Soluble Sugar ◽  
Pennisetum Alopecuroides

In this study, effects of different pretreatment methods on the enzymatic digestibility of Pennisetum alopecuroides, a ubiquitous wild grass in China, were investigated to evaluate its potential as a feedstock for biofuel production. The stalk samples were separately pretreated with H2SO4, NaOH and FeCl3 solutions of different concentrations at 120 °C for 30 min, after which enzymatic hydrolysis was conducted to measure the digestibility of pretreated samples. Results demonstrated that different pretreatments were effective at removing hemicellulose, among which ferric chloride pretreatment (FCP) gave the highest soluble sugar recovery (200.2 mg/g raw stalk) from the pretreatment stage. In comparison with FCP and dilute acid pretreatment (DAP), dilute alkaline pretreatment (DALP) induced much higher delignification and stronger morphological changes of the biomass, making it more accessible to hydrolysis enzymes. As a result, DALP using 1.2% NaOH showed the highest total soluble sugar yield through the whole process from pretreatment to enzymatic hydrolysis (508.5 mg/g raw stalk). The present work indicates that DALP and FCP have the potential to enhance the effective bioconversion of lignocellulosic biomass like P. alopecuroides, hence making this material a valuable and promising energy plant.

scholarly journals Effect of Severity Factor on the Subcritical Water and Enzymatic Hydrolysis of Coconut Husk for Reducing Sugar Production

2020 ◽  
Vol 15 (3) ◽  
pp. 786-797
Author(s):  
Maktum Muharja ◽  
Nur Fadhilah ◽  
Rizki Fitria Darmayanti ◽  
Hanny Frans Sangian ◽  
Tantular Nurtono ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Subcritical Water ◽  
Biomass Conversion ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
Sugar Production ◽  
Severity Factor ◽  
Coconut Husk ◽  
Hydrolysis Process ◽  
Hydrolysis Of

Preventing the further degradation of monomeric or oligomeric sugar into by-product during biomass conversion is one of the challenges for fermentable sugar production. In this study, the performance of subcritical water (SCW) and enzymatic hydrolysis of coconut husk toward reducing sugar production was investigated using a severity factor (SF) approach. Furthermore, the optimal condition of SCW was optimized using response surface methodology (RSM), where the composition changes of lignocellulose and sugar yield as responses. From the results, at low SF of SCW, sugar yield escalated as increasing SF value. In the enzymatic hydrolysis process, the effect of SCW pressure is a significant factor enhancing sugar yield. A maximum total sugar yield was attained on the mild SF condition of 2.86. From this work, it was known that the SF approach is sufficient parameter to evaluate the SCW and enzymatic hydrolysis of coconut husk. Copyright © 2020 BCREC Group. All rights reserved 

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