scholarly journals Effect of Combinative Pretreatments on Cellulose-to-Glucose Conversion of Empty Palm Fruit Bunch (EFB)

2014 ◽  
Vol 7 ◽  
pp. 81-85
Author(s):  
Yakindra Prasad Timilsena ◽  
Nicolas Brosse

Various methods of pretreatments were investigated to their effect on cellulose to glucose conversion efficiency on enzymatic hydrolysis of a tropical agro-industrial waste residue (empty palm fruit bunch, EFB). Four different kinds of combinative pretreatments (autohydrolysis with and without naphthol, dilute acid prehydrolysis, soda prehydrolysis and enzymatic prehydrolysis) were tested for delignification during the first and the second steps of pretreatment. Each prehydrolysis step was seconded by the organosolv delignification with the same conditions of pretreatment. It was observed that all the combinative methods were far more efficient in delignification and enzymatic hydrolysis ability as compared to its one step counter parts. The combinative pretreatment method involving dilute acid prehydrolysis followed by organosolv delignification revealed the best result with respect to lignin removal and enzymatic hydrolysis. The resultant pulp contained very low Klason lignin (~5%) with high sugar conversion ratio (64% total reducing sugars). DOI: http://dx.doi.org/10.3126/jfstn.v7i0.10613   J. Food Sci. Technol. Nepal, Vol. 7 (81-85), 2012  

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2952 ◽  
Author(s):  
Buzała ◽  
Kalinowska ◽  
Małachowska ◽  
Boruszewski ◽  
Krajewski ◽  
...  

The results of enzymatic hydrolysis of birch and beech kraft cellulosic pulps indicate that they may be promising feedstocks for fermentation processes including biofuel manufacturing. The aim of this study was to investigate whether birch and beech wood require the same degree of delignification by kraft pulping as pine wood. The differences observed in the efficiency of hydrolysis for the raw materials tested suggest that the differences in the anatomical structure of the examined wood in relation to pine wood is essential for the efficiency of the enzymatic hydrolysis process. The yields of glucose and other reducing sugars obtained from the birch and beech cellulosic pulps were similar (up to around 75% and 98.3% dry weight, and 76% and 98.6% dry weight, respectively). The highest glucose yields from cellulose contained in the birch and beech pulp were around 81.2% (at a Kappa number of 28.3) and 83.1% (at a Kappa number of 30.4), respectively. The maximum glucose yields and total reducing sugars of birch wood on a dry weight basis (39.8% and 52.1%, respectively) were derived from the pulp at a Kappa number of 28.3, while the highest yields of glucose and total reducing sugars of beech wood on a dry weight basis (around 36.9% and 48.2%, respectively) were reached from the pulp at a Kappa number of 25.3. To obtain the highest glucose yields and total reducing sugars of a wood on a dry weight basis, total lignin elimination from the birch and beech pulps was not necessary. However more in-depth delignification of birch and beech wood is required than for pine wood.


2011 ◽  
pp. 223-230
Author(s):  
Darjana Ivetic ◽  
Vesna Vasic ◽  
Marina Sciban ◽  
Mirjana Antov

This paper analyzes some chemical pretreatments of sugar beet shreds concerning generated waste flows and yield of reducing sugars obtained by enzymatic hydrolysis of pretreated material. Waste flows produced in pretreatments of sugar beet shreds originated from pectin and lignin removal from raw material. Suitability of substrates prepared in single and two-step pretreatment procedure for enzymatic hydrolysis was determined based on the yield of reducing sugars released by cellulase action on them, while different possibilities of processing of wastewaters were discussed based on the characteristic of waste flows.


2021 ◽  
Author(s):  
Wenqian Lin ◽  
Jinlai Yang ◽  
Yayue Zheng ◽  
Caoxing Huang ◽  
Qiang Yong

Abstract Background: During dilute acid pretreatment, pseudo lignin and lignin form droplets which deposit on the surface of lignocellulose, and further inhibit its enzymatic hydrolysis. However, how this lignin interacts with cellulase enzymes and then affects enzymatic hydrolysis is still unknown. In this work, different fractions of surface lignin (SL) obtained from dilute acid pretreated bamboo residues (DAP-BR) were extracted by various organic reagents and the residual lignin in extracted DAP-BR was obtained by milled wood lignin (MWL) method. All the obtained lignin fractions from DAP-BR were used to investigate the interaction mechanism between lignin and cellulase using surface plasmon resonance (SPR) technology in order to understand how they affect enzymatic hydrolysisResults: Results showed that removing surface lignin significantly decrease the enzymatic hydrolysis of DAP-BR from 36.5% to 18.6%. The addition of MWL samples to Avicel decreased enzymatic hydrolysis of Avicel, while different SL samples showed a slight increase to its enzymatic digestibility. Due to the higher molecular weight and hydrophobicity of MWL samples versus the SL samples, stronger affinity for MWL (KD = 6.8-24.7 nM) was found versus that of SL (KD = 39.4-52.6 nM) by SPR analysis. The affinity constant of all tested lignin had good correlations (R2>0.6) with their effects on enzymatic digestibility of extracted DAP-BR and Avicel.Conclusions: This work reveals that the surface lignin on DAP-BR is necessary towards maintaining enzyme digestibility levels, and its removal has a negative impact on the substrate’s digestibility.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Robinson Timung ◽  
Narendra Naik Deshavath ◽  
Vaibhav V. Goud ◽  
Venkata V. Dasu

This work was aimed at investigating the effect of process parameters on dilute acid pretreatment and enzymatic hydrolysis of spent citronella biomass (after citronella oil extraction) and sugarcane bagasse on total reducing sugar (TRS) yield. In acid pretreatment, the parameters studied were acid concentration, temperature, and time. At the optimized condition (0.1 M H2SO4, 120°C, and 120 min), maximum TRS obtained was 452.27 mg·g−1and 487.50 mg·g−1for bagasse and citronella, respectively. Enzymatic hydrolysis of the pretreated biomass usingTrichoderma reesei26291 showed maximum TRS yield of 226.99 mg·g−1for citronella and 282.85 mg·g−1for bagasse at 10 FPU, 50°C, and 48 hr. The maximum crystallinity index (CI) of bagasse and citronella after acid pretreatment obtained from X-ray diffraction analysis was 64.41% and 56.18%, respectively. Decreased CI after enzymatic hydrolysis process to 37.28% and 34.16% for bagasse and citronella, respectively, revealed effective conversion of crystalline cellulose to glucose. SEM analysis of the untreated and treated biomass revealed significant hydrolysis of holocellulose and disruption of lignin.


2020 ◽  
Vol 14 (4) ◽  
pp. 453-460
Author(s):  
Ruyi Sha ◽  
Zhan Yu ◽  
Zhenzhen Wang ◽  
Edwin Menledy Gbor ◽  
Ligang Jiang ◽  
...  

The lignin present in lignocellulose seriously affects the efficiency of cellulose enzymatic hydrolysis. In addition, lignin adsorbs high-cost cellulase, causing greater economic losses. Lignin can also disturb the site of action of cellulase and reduce the efficiency of hydrolysis. Therefore, if lignin is removed or surface modified before cellulose enzymatic hydrolysis, the enzymatic hydrolysis efficiency of lignocellulosic biomass will be greatly improved. In this paper, the cellulose enzymatic properties of bamboo biomass being treated with dilute acid and alkaline under the intervention of biosurfactant rhamnolipid were evaluated. The effects of rhamnolipids on the adsorption characterization of cellulose on pretreated bamboo were studied. Besides, the inter-communication between rhamnolipids and cellulose was investigated by fluorescence probe. The results showed that rhamnolipids could have a positive effect on the enzymatic hydrolysis of bamboo biomass by reducing the non-productive adsorption of cellulase on the surface of lignocellulose. The outcome illustrated that cellulase could be combined with rhamnolipids micelles, participating in the formation of rhamnolipids micelles, thereby increasing the internal hydrophobicity of the micelles, but could not change the properties of rhamnolipids micelles higher than one CMC (Critical Micelle Concentration). It can be seen that the interaction between rhamnolipids and cellulase is beneficial to enhance the stability and enzymatic activity of cellulase, thereby improving the enzymatic hydrolysis efficiency of cellulose in biomass. Based on these results, a theoretical knowledge about the mechanism of enhancing the enzymatic hydrolysis efficiency of lignocellulose by biosurfactants rhamnolipids is provided.


2010 ◽  
Vol 26 (5) ◽  
pp. 1245-1251 ◽  
Author(s):  
David Humbird ◽  
Ali Mohagheghi ◽  
Nancy Dowe ◽  
Daniel J. Schell

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