<i>Effects of rubbing-alkali pretreatment on enzymatic hydrolysis-reducing sugar yield and structure of rice straw</i>

2019 ◽  
Author(s):  
Yutao LIU ◽  
Weimin DING ◽  
Weihua MAO
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
Alkali Pretreatment

Effects of a Pretreatment Combining Rubbing with Dilute Alkali on the Enzymatic Hydrolysis-Reducing Sugar Yield and Structure of Rice Straw

2019 ◽  
Vol 62 (6) ◽  
pp. 1705-1711
Author(s):  
Yutao Liu ◽  
Xicun Chai ◽  
Mingmei Chi
Keyword(s):  
Enzymatic Hydrolysis ◽  
Production Rate ◽  
Rice Straw ◽  
Removal Rate ◽  
Silicon Layer ◽  
High Energy ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
Sugar Production ◽  
Alkali Pretreatment

Abstract. Current pretreatments to digest cellulose straw are characterized by high energy consumption, environmental pollution, and other problems that limit straw biomass utilization. In this work, a rice straw rubbing pretreatment that is less energy-intensive than existing pretreatments is proposed to partly destroy the silicon layer. The rubbing pretreatment did not significantly increase the enzymatic hydrolysis-reducing sugar production rate of rice straw, but it enhanced the effect of subsequent dilute alkali pretreatment. The enzymatic hydrolysis-reducing sugar production rate after combined rubbing and alkali pretreatment was 33.63%, which was significantly higher than the rates achieved with original straw and with dilute alkali pretreatment alone. Rubbing pretreatment removed 33.40% of the surface silicon from the straw. This was significantly higher than the removal rates for original straw and dilute alkali pretreatment alone, but there was no marked difference in removal rate between the rubbing pretreatment and the combined rubbing and alkali pretreatment. The results indicate that rubbing pretreatment is an effective way to promote the efficiency of alkali pretreatment, and combined rubbing and alkali pretreatment greatly enhances the efficient utilization of rice straw.Highlights33.40% of the silicon layer on the surface of rice straw was removed by the rubbing pretreatment.Cracks caused by the rubbing pretreatment are beneficial for chemical reagents to access the inner composites.The rubbing pretreatment could enhance the efficiency of follow-up treatments for rice straw. Keywords: Rice straw, Rubbing pretreatment, Silicon layer, Sugar yield, Structure.

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

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.

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

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 787 ◽  
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.

Comparison of Bacterial and Yeast Ethanol Fermentation Yield from Rice Straw

2011 ◽  
Vol 347-353 ◽  
pp. 2541-2544
Author(s):  
Benjarat Laobussararak ◽  
Warawut Chulalaksananukul ◽  
Orathai Chavalparit
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Zymomonas Mobilis ◽  
Ethanol Yield ◽  
Sugar Content ◽  
Alkali Pretreatment ◽  
Yeast Saccharomyces Cerevisiae ◽  
Pretreatment Condition ◽  
Theoretical Yield

This study was to investigate the fermentation of rice straw using various microorganisms, i.e., the bacterium Zymomonas mobilis, a distillery yeast Saccharomyces cerevisiae and a co-culture of Zymomonas mobilis and Saccharomyces cerevisiae. Rice straw was pretreated with alkaline and followed by enzymatic hydrolysis using cellulase before fermentation by the bacterium and a distillery yeast. Results show that alkali pretreatment is appropriate for rice straw since this pretreatment condition can produce the maximum cellulose of 88.96% and reducing sugar content of 9.18 g/l. Furthermore, the ethanol yield after enzymatic hydrolysis (expressed as % theoretical yield) was 15.94-19.73% for the bacterium, 20.48-35.70% for yeast and 21.56-29.89% for co-culture. Therefore, the distillery yeast was a suitable microorganism for ethanol production from rice straw.

scholarly journals Production of Xyloligosaccharides from Rice Straw by Microwave-assisted Enzymatic Hydrolysis and Evaluation of Their Prebiotic Properties

2021 ◽  
Vol 20 (2) ◽  
Author(s):  
Alisa Pattarapisitporn ◽  
Nonglak Thiangthong ◽  
Pakorn Inthajak ◽  
Pannapapol Jaichakan ◽  
Wantana Panpa ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Sugar Content ◽  
Lactobacillus Brevis ◽  
Enzyme Concentration ◽  
Reducing Sugar ◽  
Total Sugar ◽  
Microwave Pretreatment ◽  
Pretreatment Time ◽  
Layer Chromatography

Rice straw (RS) is a by-product from rice production process. It is rich in cellulose, hemicellulose and lignin. RS hemicellulose mainly composes of arabinoxylan (AX). This research aimed to investigate the potential of microwave-pretreatment in AX extraction from RS and substrate to produce xylooligosaccharides (XOS) via enzymatic hydrolysis. The extractive-free RS was pretreated by microwave process at 160°C for 5-15 min, then the AX was extracted with 4% sodium hydroxide. The total sugar and reducing sugar content of AX exhibited that increasing microwave-pretreatment time increased the yield of AX. The highest AX content was found at 160°C for 10 min as 7.73%, reducing sugar content of 11.89 mg/g, and total sugar of 165.85 mg/g. The crude AX obtained by microwave-pretreatment was then used as a substrate for XOS production by two commercial xylanases of Pentopan mono BG (BG) and Ultraflo Max (UM), at the enzyme concentration of 50-300 U/g AX (50°C, pH 6.0) for 24 h.The reducing sugar content and sugar profiles were monitored by DNS assay,and thin layer chromatography (TLC) which revealed that BG 50 U/g at 12 h andUM 50 U/g at 24 h showed the promising reducing sugar of 16.4 and 25.44 mg/g,respectively. The composition of XOS derived from RS (RS-XOS) prepared by BGwas xylobiose (X2), xylotriose (X3), xylotretraose (X4), and xylopentaose (X5)while by UM was xylobiose (X2), xylotriose (X3) and xylotretraose (X5). Moreover,XOS produced by BG contained very low amount of xylose (X1). In addition, theRS-XOS could the growth of Lactobacillus brevis greater than commercial XOS.

scholarly journals High-temperature heating and microwave pretreatments: A new light in bamboo's enzymatic hydrolysis

2016 ◽  
Vol 20 (3) ◽  
pp. 999-1002 ◽  
Author(s):  
Jiajia Fu ◽  
Yu Li ◽  
Qun Zhang ◽  
Shen Shen ◽  
Xiao-Ying Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Enzymatic Hydrolysis ◽  
Protein Adsorption ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
X Ray ◽  
Temperature Heating ◽  
Hydrolysis Of ◽  
High Temperature Heating

A combined technology of high-temperature heating and microwave is proposed to treat bamboo substrates prior to enzymatic hydrolysis to overcome the limits of ei- ther technology. The combined technology helps to promote the reducing sugar yield from enzymatic hydrolysis of bamboo. The protein adsorption test indicated that more enzyme proteins could adsorb on the surface of bamboo pretreated by the combined technology. Thus, the possibility of enzymes to hydrolyze bamboo increased. Meanwhile, X-ray diffractometry tested revealed that the combined technology benefited the removal of non-cellulosic substances from bamboo and resulted in a higher crystallinity.

scholarly journals Optimisation of enzymatic saccharification of wheat straw pre-treated with sodium hydroxide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhiquan Wang ◽  
Suqing Wu ◽  
Chunzhen Fan ◽  
Xiangyong Zheng ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Treatment Time ◽  
Solid Content ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
Experimental Result ◽  
Enzyme Loading ◽  
Hydrolysis Time ◽  
Pre Treatment

AbstractTo enhance the reducing sugar yield in enzymatic hydrolysis, various factors (NaOH concentration, solid content and pre-treatment time) that affect the pre-treatment process were investigated and evaluated based on the reducing sugar yield of the subsequent enzymatic hydrolysis. The enzymatic hydrolysis was based on the cellulase from Trichoderma reesi ATCC 26921, the optimum NaOH pre-treatment conditions were an NaOH concentration of 1.0% (w/w), a solid content of 5.0% (w/v) and a pre-treatment time of 60 min. Various parameters that affect the enzymatic hydrolysis of wheat straw, including the solid content, enzyme loading, pH and hydrolysis time, were investigated and optimized through a Box–Behnken design and response surface methodology. The predicted optimum conditions for enzymatic hydrolysis were a solid content of 8.0% (w/v), an enzyme loading of 35 FPU/g substrate, a temperature of 50 °C, a pH of 5.3 and a hydrolysis time of 96 h. The experimental result showed that the maximum reducing sugar yield was 60.73% (53.35% higher than the wheat straw without NaOH pre-treatment), which is in accordance with the predicted conditions.

scholarly journals Sono-Assisted Alkali and Dilute Acid Pretreatment of Phragmites karka (Tall Reed Grass) to Enhance Enzymatic Digestibility for Bioethanol Conversion

2021 ◽  
Vol 8 ◽  
Author(s):  
Sabeela Beevi Ummalyma ◽  
Dinabandhu Sahoo ◽  
Anoop Pudiyamadam ◽  
Velayudhanpillai Prasannakumari Adarsh ◽  
Rajeev K. Sukumaran ◽  
...  
Keyword(s):  
Reducing Sugar ◽  
Sugar Yield ◽  
Dilute Acid Pretreatment ◽  
Biofuel Production ◽  
Cellulose Content ◽  
Waste Biomass ◽  
Dilute Acid ◽  
Alkali Pretreatment ◽  
Acid Pretreatment ◽  
Phragmites Karka

Phragmites is the tallest energy crop found as an invasive species worldwide and considered as waste biomass. The present study evaluated the potential of the aquatic biomass Phragmites karka grown from two different lakes as feedstock for biofuel production. A comparative study of biomass was conducted from Chilika Lake and Loktak Lake, India. The methodology involves dilute acid, sono-assisted alkali pretreatment, and hydrolyzed biomass with commercial cellulase. SEM, XRD, and FTIR analysis were performed for the biomass physicochemical studies and confirmed that alterations occurred in the biomass structure, assisting the hydrolysis process. The enzymatic hydrolysis result showed that the highest of reducing sugar yield of 79% was obtained from biomass loading of 10% and 1% w/v alkali with a sonication frequency of 20 kHz for 25 min. Acid pretreatment released maximal reducing sugar yield of 73% attained from biomass loading of 20% and 0.5% w/v acid. Composition analysis of biomass showed that cellulose content increased from 36% to 46%. Sono-assisted alkali pretreatment solubilized 40% of lignin content compared to untreated biomass. Final ethanol recovery from the biomass is 78% fermentation efficiency from glucose. The data indicate that exploiting tall reed grass as a bioenergy raw material can be a viable approach for sustainable utilization of invasive grass/waste biomass for biorefineries, which helps control invasive weeds and management of waste.

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 Enzymatic Hydrolysis of Blend of Lignicellulosic Materials for Reducing Sugar Production: Screening of Significant Process Factors

2020 ◽  
pp. 1-10
Author(s):  
Bathlomew Chukwudi Amadi ◽  
Philomena Kañulia Igbokwe ◽  
Chijioke Elijah Onu
Keyword(s):  
Enzymatic Hydrolysis ◽  
Process Parameters ◽  
Confidence Level ◽  
Statistical Significance ◽  
Latin Square ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
Blend Ratio ◽  
Process Factors ◽  
Hydrolysis Of

The screening of the process parameters on the enzymatic hydrolysis of a blend of two lignocellulosic materials - corn cob (CC) and deseeded fluted pumpkin fruit (DFPF) using Trichoderma reesei was the focus of the present study. Four process parameters – time, temperature, substrate blend ratio and pH were screened for statistical significance using a 4 x 4 matrix of Graeco-Latin square design of experiment. The reducing sugar yield was determined using the dinitrosalisylic acid (DNS) method and maximum reducing sugar yield of 57.92mg/ml obtained in 2days at 40oC, blend ratio of 0.2:0.8 (CC:DFPF) and pH 5.5. Result of the Analysis of Variance (ANOVA) obtained showed that with 3 degrees of freedom and 6 residual degree of freedom at 95% confidence level (i.e. 0.05 significance), time, temperature and substrate blend ratio significantly affected the enzymatic hydrolysis process whereas the effect of pH was not significant. However, only time was significant at 99% confidence level (0.01 significance) while temperature, substrate blend ratio and pH were not significant. This study has highlighted the significant factors among the process variables in emzymatic hydrolysis of a blend of CC and DFPF.

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