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

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.

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Derived high reducing sugar and lignin colloid particles from corn stover

BMC Chemistry ◽

10.1186/s13065-020-00725-y ◽

2020 ◽

Vol 14 (1) ◽

Author(s):

Wei Liu ◽

Shengnan Zhuo ◽

Mengying Si ◽

Mengting Yuan ◽

Yan Shi

Keyword(s):

Corn Stover ◽

Lignocellulosic Biomass ◽

Alternative Energy ◽

Reducing Sugar ◽

Sugar Yield ◽

Potential Candidate ◽

Practical Utilization ◽

Lignin Concentration ◽

Colloid Particles ◽

G Ratio

AbstractLignocellulosic biomass is considered as the largest potential candidate to develop alternative energy, such as biofuel, biomaterial. However, the efficient conversion of cellulose and practical utilization of lignin are great challenges for sustainable biorefinery. In this study, high reducing sugar yield and different size of lignin colloid particles (LCPs) were obtained via tetrahydrofuran–water (THF–H2O) pretreatment of corn stover (CS). THF–H2O as a co-solvent, could efficiently dissolve lignin and retain cellulose. After the pretreatment, 640.87 mg/g of reducing sugar was produced, that was 6.66-fold higher than that of the untreated CS. Meanwhile, the pretreatment liquor could form spherical LCPs with different sizes ranged from 202 to 732 nm through self-assembly. We studied the optimal pretreatment condition to simultaneously realize the high reducing sugar yield (588.4 mg/g) and excellent LCPs preparation with average size of 243 nm was under TH22 (THF–H2O pretreatment at 120 °C for 2 h). To further explore the formation of LCPs with different sizes. We studied the lignin structure changes of various conditions, concluded the size of LCPs was related to the lignin concentration and syringyl/guaiacyl (S/G) ratio. As the increase of the lignin concentration and S/G, the sizes of LCPs were increased. G-type lignin was easier to dissolve in the mild pretreatment supernatant, contributing to form smaller LCPs with a good dispersibility. In the severe condition, both of S and G-type lignin were dissolved due to the lignin depolymerization, formed the larger sphere particles. This work provides a novel perspective for the technical design of lignocellulosic biomass conversion.

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Evaluation of the Interactive Effect Pretreatment Parameters via Three Types of Microwave-Assisted Pretreatment and Enzymatic Hydrolysis on Sugar Yield

Processes ◽

10.3390/pr8070787 ◽

2020 ◽

Vol 8 (7) ◽

pp. 787 ◽

Cited By ~ 1

Author(s):

Saleem Ethaib ◽

Rozita Omar ◽

Mustapa Kamal Siti Mazlina ◽

Awang Biak Dayang Radiah

Keyword(s):

Response Surface Methodology ◽

Enzymatic Hydrolysis ◽

Interactive Effect ◽

Reducing Sugar ◽

Sugar Yield ◽

Solid Loading ◽

Acid Pretreatment ◽

Glucose Yield ◽

Sago Palm ◽

Microwave Assisted

This study aims to evaluate the sugar yield from enzymatic hydrolysis and the interactive effect pretreatment parameters of microwave-assisted pretreatment on glucose and xylose. Three types of microwave-assisted pretreatments of sago palm bark (SPB) were conducted for enzymatic hydrolysis, namely: microwave-sulphuric acid pretreatment (MSA), microwave-sodium hydroxide pretreatment (MSH), and microwave-sodium bicarbonate (MSB). The experimental design was done using a response surface methodology (RSM) and Box–Behenken Design (BBD). The pretreatment parameters ranged from 5–15% solid loading (SL), 5–15 min of exposure time (ET), and 80–800 W of microwave power (MP). The results indicated that the maximum total reducing sugar was 386 mg/g, obtained by MSA pretreatment. The results also illustrated that the higher glucose yield, 44.3 mg/g, was found using MSH pretreatment, while the higher xylose yield, 43.1 mg/g, resulted from MSA pretreatment. The pretreatment parameters MP, ET, and SL showed different patterns of influence on glucose and xylose yield via enzymatic hydrolysis for MSA, MSH, and MSB pretreatments. The analyses of the interactive effect of the pretreatment parameters MP, ET, and SL on the glucose yield from SPB showed that it increased with the high MP and longer ET, but this was limited by low SL values. However, the analysis of the interactive effect of the pretreatment parameters on xylose yields revealed that MP had the most influence on the xylose yield for MSA, MSH, and MSB pretreatments.

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Evaluation of commercial cellulase preparations for the efficient hydrolysis of hydrothermally pretreated empty fruit bunches

BioResources ◽

10.15376/biores.12.4.7834-7840 ◽

2017 ◽

Vol 12 (4) ◽

pp. 7834-7840 ◽

Cited By ~ 4

Author(s):

Jungwoo Yang ◽

Ji Eun Kim ◽

Jae Kyun Kim ◽

Sung ho Lee ◽

Ju-Hyun Yu ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Lignocellulosic Biomass ◽

Enzymatic Saccharification ◽

Glucose Yield ◽

Pretreatment Method ◽

Biomass Feedstocks ◽

Empty Fruit Bunches ◽

Hydrolysis Of

The performance of cellulase in the enzymatic saccharification of lignocellulose depends on the characteristics of lignocellulosic biomass feedstocks and the pretreatment method used. Efficient hydrolysis of specifically pretreated lignocellulose necessitates the knowledge of the characteristics of the optimal commercial cellulases. In this study, commercial cellulase preparations (Accellerase™ 1000, Accellerase® 1500, and Spezyme® CP from DuPont and Cellic® CTec2 from Novozymes) were evaluated for their hydrolysis efficiency of hydrothermally pretreated empty fruit bunches (EFBs). The highest glucose yields of 91.3% and 84.7% were achieved for 30 FPU of Cellic® CTec2/g glucan with and without Cellic® HTec2, respectively. Of the four cellulases tested, Cellic® CTec2, which showed the highest cellobiohydrolase, xylanase, and β-glucosidase activities, showed the highest glucose yield in the enzymatic hydrolysis of hydrothermally pretreated EFBs. The results of this study are valuable for those who plan to enzymatically hydrolyze hydrothermally pretreated EFBs.

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Biological pretreatment of corn stover for enhancing enzymatic hydrolysis using Bacillus sp. P3

Bioresources and Bioprocessing ◽

10.1186/s40643-021-00445-8 ◽

2021 ◽

Vol 8 (1) ◽

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 ◽

Reducing Sugar ◽

Biological Pretreatment ◽

Hydrolysis Process ◽

Hemicellulose Removal ◽

Hydrolysis Of

AbstractThe biological pretreatment for the enzymatic hydrolysis of lignocellulosic biomasses depends exclusively on the effective pretreatment process. Herein, we report a significant enhancement of enzymatic saccharification obtained with corn stover using a bacterial strain 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 as well as other enzymes 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 a 20-day 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 of commercial cellulase, the yield of reducing sugar released from 20-day 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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Process Design Report for Stover Feedstock: Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis for Corn Stover

10.2172/1218326 ◽

2002 ◽

Cited By ~ 231

Author(s):

A. Aden ◽

M. Ruth ◽

K. Ibsen ◽

J. Jechura ◽

K. Neeves ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Corn Stover ◽

Lignocellulosic Biomass ◽

Process Design ◽

Dilute Acid ◽

Biomass To Ethanol

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Optimization of Fermentable Sugar Production from Pineapple Leaf Waste (Ananas comosus [L.] Merr) by Enzymatic Hydrolysis

Jurnal Presipitasi Media Komunikasi dan Pengembangan Teknik Lingkungan ◽

10.14710/presipitasi.v18i1.73-80 ◽

2021 ◽

Vol 18 (1) ◽

pp. 73-80

Author(s):

Yohanita Restu Widihastuty ◽

Sutini Sutini ◽

Aida Nur Ramadhani

Keyword(s):

Enzymatic Hydrolysis ◽

Complex Structure ◽

Reducing Sugar ◽

Sugar Yield ◽

Ananas Comosus ◽

Optimum Operating ◽

Cellulose Content ◽

Optimum Operating Condition ◽

Operating Condition ◽

Cellulase Enzyme

Pineapple leaf waste is one agricultural waste that has high cellulose content. Pineapple leaf waste's complex structure contains a bundle of packed fiber that makes it hard to remove lignin and hemicellulose structure, so challenging to produce reducing sugar. Dried pineapple leaf waste pretreated with a grinder to break its complex structure. Delignification process using 2% w/v NaOH solution at 87oC for 60 minutes has been carried out to remove lignin and hemicellulose structure so reducing sugar could be produced. Delignified pineapple leaf waste has been enzymatic hydrolyzed using cellulase enzyme (6 mL, 7 mL, and 8 mL) to produce reducing sugar. The sample was incubated in an incubator shaker at 155 rpm at 45, 55, and 60oC for 72 hours. Determination of reducing sugar yield had been carried out using the Dubois method and HPLC. The model indicated that the optimum operating condition of enzymatic hydrolysis is 7 mL of cellulase enzyme at 55oC to produce 96,673 mg/L reducing sugar. This result indicated that the enzymatic hydrolysis operating condition improved the reducing sugar yield from pineapple leaf waste. The optimum reducing sugar yield can produce biofuel by the saccharification process.

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Reducing sugar loss in enzymatic hydrolysis of ethylenediamine pretreated corn stover

Bioresource Technology ◽

10.1016/j.biortech.2016.11.031 ◽

2017 ◽

Vol 224 ◽

pp. 405-410 ◽

Cited By ~ 8

Author(s):

Wen-Chao Li ◽

Xia Li ◽

Lei Qin ◽

Jia-Qing Zhu ◽

Xiao Han ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Corn Stover ◽

Reducing Sugar ◽

Pretreated Corn Stover ◽

Hydrolysis Of ◽

Sugar Loss

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Development of an integrated thermal and enzymatic hydrolysis for lignocellulosic biomass in fixed-bed reactors

Holzforschung ◽

10.1515/hf.2011.061 ◽

2011 ◽

Vol 65 (4) ◽

Cited By ~ 13

Author(s):

Christian Kirsch ◽

Carsten Zetzl ◽

Irina Smirnova

Keyword(s):

Enzyme Activity ◽

Enzymatic Hydrolysis ◽

Lignocellulosic Biomass ◽

Elevated Temperatures ◽

Enzyme Stability ◽

Fixed Bed ◽

Residual Activity ◽

Fixed Bed Reactor ◽

Shear Forces ◽

Glucose Yield

Abstract The limitations of the current biorefinery process utilizing stirred-tank reactors for the enzymatic step include poor mixing in the case of high biomass loadings, additional steps for the product separation, and a long reaction time. In this study the hydrothermal pretreatment and the enzymatic hydrolysis of the lignocellulosic biomass were combined in one fixed-bed reactor. The influence of the shear forces during recirculation and enzyme stability at elevated temperatures were investigated. It has been shown that the shear forces resulting from pumping have a negligible effect on enzyme activity. However, large pressure drops reduce the enzyme activity significantly. Furthermore, the enzyme stability was significantly increased at elevated temperatures (60°C) by applying static pressures up to 200 bar (56% residual activity at 60°C after 24 h). This is beneficial for the process as a higher temperature accelerates the reaction. Further improvement of the overall process efficiency was achieved by increasing the solid-to-water ratio and circulation of the enzyme solution. At a biomass content of 7%, a glucose concentration of 61 g l-1 and a yield of 85% was achieved. The integrated process was first done on a laboratory scale (50 ml). At 100 bar, 60°C and 10% biomass loading an increased initial reaction rate was observed. However, this effect was followed by the stagnation of the glucose yield as one of the enzymes, Novozyme 188, showed no remarkable stabilization with pressure. Nevertheless, an overall glucose yield of 40% was achieved after 5.5 h, compared to 14 h under normal pressure and 50°C.

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Valorization of Alkaline Peroxide Mechanical Pulp by Metal Chloride-Assisted Hydrotropic Pretreatment for Enzymatic Saccharification and Cellulose Nanofibrillation

Polymers ◽

10.3390/polym11020331 ◽

2019 ◽

Vol 11 (2) ◽

pp. 331 ◽

Cited By ~ 7

Author(s):

Huiyang Bian ◽

Xinxing Wu ◽

Jing Luo ◽

Yongzhen Qiao ◽

Guigan Fang ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Lignocellulosic Biomass ◽

Lignin Content ◽

Enzymatic Saccharification ◽

Fiber Surface ◽

Cost Effective ◽

Metal Chloride ◽

Fractionation Process ◽

Metal Chlorides ◽

Alkaline Peroxide

Developing economical and sustainable fractionation technology of lignocellulose cell walls is the key to reaping the full benefits of lignocellulosic biomass. This study evaluated the potential of metal chloride-assisted p-toluenesulfonic acid (p-TsOH) hydrolysis at low temperatures and under acid concentration for the co-production of sugars and lignocellulosic nanofibrils (LCNF). The results indicated that three metal chlorides obviously facilitated lignin solubilization, thereby enhancing the enzymatic hydrolysis efficiency and subsequent cellulose nanofibrillation. The CuCl2-assisted hydrotropic pretreatment was most suitable for delignification, resulting in a relatively higher enzymatic hydrolysis efficiency of 53.2%. It was observed that the higher residual lignin absorbed on the fiber surface, which exerted inhibitory effects on the enzymatic hydrolysis, while the lower lignin content substrates resulted in less entangled LCNF with thinner diameters. The metal chloride-assisted rapid and low-temperature fractionation process has a significant potential in achieving the energy-efficient and cost-effective valorization of lignocellulosic biomass.

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