An optimum combined severity factor improves both the enzymatic saccharification yield and the functional lignin structure

Cellulose ◽  
2019 ◽  
Vol 26 (8) ◽  
pp. 4731-4742 ◽  
Author(s):  
Sujuan Yuan ◽  
Xingxiang Ji ◽  
Hairui Ji ◽  
Zhongjian Tian ◽  
Jiachuan Chen
Keyword(s):  
Enzymatic Saccharification ◽  
Severity Factor ◽  
Combined Severity Factor ◽  
Saccharification Yield ◽  
Lignin Structure

scholarly journals Improvement of enzymatic saccharification in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

2015 ◽  
Author(s):  
Lizeth Núñez-López ◽  
Andrés Aguirre-Cruz ◽  
Blanca Estela Barrera-Figueroa ◽  
Julian Mario Peña-Castro
Keyword(s):  
Transcription Factor ◽  
Ectopic Expression ◽  
Enzymatic Saccharification ◽  
Biofuel Production ◽  
Starch Accumulation ◽  
Starch Degradation ◽  
Photosynthetic Parameters ◽  
Wild Type ◽  
Submergence Stress ◽  
Saccharification Yield

Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene) can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0), mainly from accumulated starch. This high saccharification yield was developmentally controlled since juvenile transgenic plants yielded 200-300% more glucose than Col-0. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1), juvenile transition (SPL3-5) and meristematic identity (FUL, SOC1) but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production.

scholarly journals Pilot Scale Elimination of Phenolic Cellulase Inhibitors From Alkali Pretreated Wheat Straw for Improved Cellulolytic Digestibility to Fermentable Saccharides

2021 ◽  
Vol 9 ◽  
Author(s):  
Ikram ul Haq ◽  
Ali Nawaz ◽  
Badar Liaqat ◽  
Yesra Arshad ◽  
Xingli Fan ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Wheat Straw ◽  
Phenolic Content ◽  
Enzymatic Saccharification ◽  
Dry Weight ◽  
Pilot Scale ◽  
Total Phenolic ◽  
Saccharification Yield ◽  
Pre Treatment ◽  
Pretreated Wheat Straw

Depleting supplies of fossil fuel, regular price hikes of gasoline and environmental deterioration have necessitated the search for economic and eco-benign alternatives of gasoline like lignocellulosic biomass. However, pre-treatment of such biomass results in development of some phenolic compounds which later hinder the depolymerisation of biomass by cellulases and seriously affect the cost effectiveness of the process. Dephenolification of biomass hydrolysate is well cited in literature. However, elimination of phenolic compounds from pretreated solid biomass is not well studied. The present study was aimed to optimize dephenoliphication of wheat straw using various alkalis i.e., Ca(OH)2 and NH3; acids i.e., H2O2, H2SO4, and H3PO4; combinations of NH3+ H3PO4 and H3PO4+ H2O2 at pilot scale to increase enzymatic saccharification yield. Among all the pretreatment strategies used, maximum reduction in phenolic content was observed as 66 mg Gallic Acid Equivalent/gram Dry Weight (GAE/g DW), compared to control having 210 mg GAE/g DW using 5% (v/v) combination of NH3+H3PO4. Upon subsequent saccharification of dephenoliphied substrate, the hydrolysis yield was recorded as 46.88%. Optimized conditions such as using 1%+5% concentration of NH3+ H3PO4, for 30 min at 110°C temperature reduced total phenolic content (TPC) to 48 mg GAE/g DW. This reduction in phenolic content helped cellulases to act more proficiently on the substrate and saccharification yield of 55.06% was obtained. The findings will result in less utilization of cellulases to get increased yield of saccharides by hydrolyzing wheat straw, thus, making the process economical. Furthermore, pilot scale investigations of current study will help in upgrading the novel process to industrial scale.

scholarly journals Effect of alkaline lignin modification on cellulase–lignin interactions and enzymatic saccharification yield

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenjun Ying ◽  
Zhengjun Shi ◽  
Haiyan Yang ◽  
Gaofeng Xu ◽  
Zhifeng Zheng ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Lignin Modification ◽  
Saccharification Yield

scholarly journals Improvement of enzymatic saccharification in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

2015 ◽  
Author(s):  
Lizeth Núñez-López ◽  
Andrés Aguirre-Cruz ◽  
Blanca Estela Barrera-Figueroa ◽  
Julian Mario Peña-Castro
Keyword(s):  
Transcription Factor ◽  
Ectopic Expression ◽  
Enzymatic Saccharification ◽  
Biofuel Production ◽  
Starch Accumulation ◽  
Starch Degradation ◽  
Photosynthetic Parameters ◽  
Wild Type ◽  
Submergence Stress ◽  
Saccharification Yield

Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene) can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0), mainly from accumulated starch. This high saccharification yield was developmentally controlled since juvenile transgenic plants yielded 200-300% more glucose than Col-0. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1), juvenile transition (SPL3-5) and meristematic identity (FUL, SOC1) but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production.

scholarly journals Pretreatment of Oil Palm Empty Fruit Bunch (OPEFB) at Bench-Scale High Temperature-Pressure Steam Reactor for Enhancement of Enzymatic Saccharification

2020 ◽  
Author(s):  
Fahriya Puspita Sari ◽  
Faizatul Falah ◽  
Sita Heris Anita ◽  
Kharisma Panji Ramadhan ◽  
Raden Permana Budi Laksana ◽  
...  
Keyword(s):  
High Temperature ◽  
Optimum Condition ◽  
Oil Palm ◽  
Enzymatic Saccharification ◽  
Steam Pretreatment ◽  
Chemical Compositions ◽  
Empty Fruit Bunch ◽  
Severity Factor ◽  
Bench Scale ◽  
Pressure Steam

Up scaling of biomass pretreatment from laboratory scale to a bench-scale reactor is one of important steps in the application of the pretreatment for pilot or commercial scale.  This study reports the optimization of pretreatment conditions, namely reaction temperature and time, by one factor at a time (OFAT) method for the enhancement of enzymatic saccharification of oil palm empty fruit bunch (OPEFB). OPEFB was pretreated using high temperature-pressure steam reactor with different reaction temperatures (160, 170, 180, 190, 200 °C) and times (10, 20, 30, 40, 50 min). The effectiveness of the pretreatment was determined based on chemical compositions of untreated and pretreated OPEFB and sugar production from enzymatic saccharification of the pretreated OPEFB.  Solubilized components in the water that generates the steam were also determined. Pretreatment at 180°C for 20 min provides the highest sugar yields (97.30% of glucose yield per initial cellulose and 88.86% of xylose yield per initial hemicellulose). At the optimum condition 34.9% of lignin and 30.75% of hemicellulose were successfully removed from the OPEFB and resulted in 3.43 delignification selectivity. The relationship between severity factor and by-products generated and the sugars obtained after enzymatic saccharification were discussed. The pretreated OPEFB at the optimum condition was also characterized for its morphological characteristic by scanning electron microscopy (SEM) and crystallinity by X-ray diffractometry (XRD) and then compared it with untreated one. The steam pretreatment caused some fiber disruptions with more defined and opened structures and increased of the crystallinity index (CrI) by 2.9% compared to the untreated OPEFB

scholarly journals Acid-Catalyzed Wet Torrefaction for Enhancing the Heating Value of Barley Straw

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1693
Author(s):  
Antonios Nazos ◽  
Panagiotis Grammelis ◽  
Elias Sakellis ◽  
Dimitrios Sidiras
Keyword(s):  
Batch Reactor ◽  
Barley Straw ◽  
Energy Yield ◽  
Severity Factor ◽  
Heating Value ◽  
Box Behnken Design ◽  
Treatment Conditions ◽  
Combined Severity Factor ◽  
Acid Catalyzed ◽  
Composition Changes

In the present study, the possibility of improving the higher heating value (HHV) of lignocellulosic biomass, especially barley straw, was examined. The research deals with the treatment of barley straw by acid-catalyzed wet torrefaction (ACWT), also called acid hydrolysis, in a batch reactor (autoclave) Parr 4553 3.75 L. In this case, two different simulation approaches were applied: (i) combined severity factor (CSF) and (ii) response surface methodology (RSM) based on Box–Behnken design of experiments (DoE). Sulfuric acid (SA) concentration, temperature and time were the ACWT parameters examined herein. An oxygen bomb calorimeter was used for the HHV measurement. The findings indicated that the composition changes of the straw due to ACWT had a significant effect on the HHV of the pretreated material. In this study, treatment conditions were 10–35 mM SA, 160–200 °C and an isothermal reaction time 0–40 min (preheating period not included in these values). In conclusion, there was a significant increase in the HHV up to 24.3 MJ/kg for the ACWT barley straw, compared to 17.5 MJ/kg for the untreated straw, at optimal conditions of 200 °C for 25 min (isothermal period) and 35 mM SA. This resulted in a 1.39 enhancement factor (EF) and 68% energy yield (EY).

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