scholarly journals INFLUENCE OF ULTRA LOW AND HIGH TEMPERATURE ON ENZYMATIC PRETREATMENT OF BEECH BRANCHES WOOD

Wood Research ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 630-642
Author(s):  
MICHAL HALAJ ◽  
ŠTEFAN BOHÁČEK ◽  
ANDREJ PAŽITNÝ ◽  
VLADIMÍR KUŇA ◽  
JOZEF BALBERČÁK
Keyword(s):  
High Temperature ◽  
Enzymatic Hydrolysis ◽  
Water Uptake ◽  
Beech Wood ◽  
Positive Influence ◽  
Cellulose Content ◽  
Enzymatic Pretreatment ◽  
Cell Destruction ◽  
Maximum Water

The publication is focused on the effect of ultra low and high temperature on enzymatic pretreatment of beech wood (Fagus sylvaticaL.). Two fractions < 0.7 mm and 1.0 –2.5 mm of disintegrated branches sawdust were used for experiments. Glucose and xylose yields were measured after 24, 48, and 72 hours of enzymatic hydrolysis with 15 % load of the enzyme measured to total cellulose content. The influence of freezing under -80°C and boiling under pressure at +160°C on samples before enzymatic hydrolysis was observed. Mutual combination of boiling under pressure to obtain the maximum water uptake and subsequent freezing was used to better understand the process of cell destruction. The results show that the boiling pretreatment has a positive influence on thetotal monosaccharide yields and the subsequent freezing may slightly increase these yields even further. The maximum monosaccharide conversion (73.24%) was achieved using the fraction < 0.7 mm.

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 A novel high performance metagenome-derived alkali-thermostable endo-β-1,4-glucanase for lignocellulosic biomass hydrolysis in the harsh conditions

2020 ◽  
Author(s):  
Shohreh Ariaeenejad ◽  
Atefeh Sheykhabdolahzadeh ◽  
Morteza Maleki ◽  
Kaveh Kavousi ◽  
Mehdi Foroozandeh Shahraki ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Rice Straw ◽  
Specific Activity ◽  
Agricultural Waste ◽  
Extreme Temperature ◽  
In Silico Analysis ◽  
Cellulose Content ◽  
Biomass Hydrolysis ◽  
Harsh Condition

Abstract Background: Lignocellulosic biomass, is a great resource for the production of bio-energy and bio-based material since it is largely abundant, inexpensive and renewable. The requirement of new energy sources has led to a wide search for novel effective enzymes to improve the exploitation of lignocellulose, among which the importance of thermostable and halotolerant cellulase enzymes with high pH performance is significant. Results: The primary aim of this study was to discover a novel alkali-thermostable endo-β-1,4-glucanase from the sheep rumen metagenome. Using a multi-step in-silico analysis, primary candidates with desired properties were found and subjected to cloning, expression, and purification followed by functional and structural characterization. The enzymes' kinetic parameters, including V max , Km, and specific activity, were calculated. The PersiCel4 demonstrated its optimum activity at pH 8.5 and a temperature of 85°C and was able to retain more than 70% of its activity after 150 hours of storage at 85°C. Furthermore, this enzyme was able to maintain its catalytic activity in the presence of different concentrations of NaCl, MgCl 2 , CaCl 2 , and MnCl 2 . Our results showed that treatment with MnCl 2 could enhance the enzyme’s activity by 89%. PersiCel4 was ultimately used for enzymatic hydrolysis of autoclave pretreated rice straw, the most abundant agricultural waste with rich cellulose content. In autoclave treated rice straw, enzymatic hydrolysis with the PersiCel4 increased the release of reducing sugar up to 260% after 72 hours in the harsh condition ( T= 85°C, pH = 8.5). Conclusion: Considering the urgent demand for stable cellulases that are operational on extreme temperature and pH conditions and due to several proposed distinctive characteristics of PersiCel4, it can be used in the harsh condition for bioconversion of lignocellulosic biomass.

scholarly journals Enzymatic sugar production from elephant grass and reed straw through pretreatments and hydrolysis with addition of thioredoxin-His-S

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xianqin Lu ◽  
Can Li ◽  
Shengkui Zhang ◽  
Xiaohan Wang ◽  
Wenqing Zhang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Pennisetum Purpureum ◽  
Commercial Application ◽  
Hydrolysis Lignin ◽  
Cellulose Content ◽  
Sugar Production ◽  
Elephant Grass ◽  
Reed Straw ◽  
Hydrolysis Yield ◽  
Hydrolysis Of

Abstract Background The bioconversion of lignocellulose to fermentable C5/C6-saccharides is composed of pretreatment and enzymatic hydrolysis. Lignin, as one of the main components, resists lignocellulose to be bio-digested. Alkali and organosolv treatments were reported to be able to delignify feedstocks and loose lignocellulose structure. In addition, the use of additives was an alternative way to block lignin and reduce the binding of cellulases to lignin during hydrolysis. However, the relatively high cost of these additives limits their commercial application. Results This study explored the feasibility of using elephant grass (Pennisetum purpureum) and reed straw (Phragmites australis), both of which are important fibrous plants with high biomass, no-occupation of cultivated land, and soil phytoremediation, as feedstocks for bio-saccharification. Compared with typical agricultural residues, elephant grass and reed straw contained high contents of cellulose and hemicellulose. However, lignin droplets on the surface of elephant grass and the high lignin content in reed straw limited their hydrolysis performances. High hydrolysis yield was obtained for reed straw after organosolv and alkali pretreatments via increasing cellulose content and removing lignin. However, the hydrolysis of elephant grass was only enhanced by organosolv pretreatment. Further study showed that the addition of bovine serum albumin (BSA) or thioredoxin with His- and S-Tags (Trx-His-S) improved the hydrolysis of alkali-pretreated elephant grass. In particular, Trx-His-S was first used as an additive in lignocellulose saccharification. Its structural and catalytic properties were supposed to be beneficial for enzymatic hydrolysis. Conclusions Elephant grass and reed straw could be used as feedstocks for bioconversion. Organosolv and alkali pretreatments improved their enzymatic sugar production; however, the increase in hydrolysis yield of pretreated elephant grass was not as effective as that of reed straw. During the hydrolysis of alkali-pretreated elephant grass, Trx-His-S performed well as additive, and its structural and catalytic capability was beneficial for enzymatic hydrolysis.

PROTON-CONDUCTING POLYMERS AS ELECTROLYTE FOR FUEL CELLS

NANO ◽  
2008 ◽  
Vol 03 (05) ◽  
pp. 381-386 ◽  
Author(s):  
DANIELA EBRASU ◽  
IOAN STAMATIN ◽  
ASHOK VASEASHTA
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Conducting Polymers ◽  
Polymer Electrolyte ◽  
Water Uptake ◽  
Water Retention ◽  
Polymer Electrolyte Membrane ◽  
Electrolyte Membrane ◽  
Simple Processing ◽  
Processing Steps

The objective of this investigation is to evaluate a series of polymer electrolyte membrane materials based on sulfonated ladder pyridine polymers and SiO 2 nanoparticles that enhance water retention and favor high temperature (> 120°C) applications. Nanoparticles are used to improve water uptake at levels of 20–38% to increase the level of sulfonation. A study of relevant characteristics of these polymers will provide an alternative to existing polymers, thus offering simple processing steps, as well as nonexotic polymers and higher performances.

scholarly journals Biological Pretreatment of Rubberwood withCeriporiopsis subvermisporafor Enzymatic Hydrolysis and Bioethanol Production

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Forough Nazarpour ◽  
Dzulkefly Kuang Abdullah ◽  
Norhafizah Abdullah ◽  
Nazila Motedayen ◽  
Reza Zamiri
Keyword(s):  
Particle Size ◽  
Enzymatic Hydrolysis ◽  
Raw Material ◽  
White Rot ◽  
White Rot Fungus ◽  
Cellulose Content ◽  
Bioethanol Production ◽  
Biological Pretreatment ◽  
Spectra Analysis ◽  
Alternative Material

Rubberwood (Hevea brasiliensis), a potential raw material for bioethanol production due to its high cellulose content, was used as a novel feedstock for enzymatic hydrolysis and bioethanol production using biological pretreatment. To improve ethanol production, rubberwood was pretreated with white rot fungusCeriporiopsis subvermisporato increase fermentation efficiency. The effects of particle size of rubberwood (1 mm, 0.5 mm, and 0.25 mm) and pretreatment time on the biological pretreatment were first determined by chemical analysis and X-ray diffraction and their best condition obtained with 1 mm particle size and 90 days pretreatment. Further morphological study on rubberwood with 1 mm particle size pretreated by fungus was performed by FT-IR spectra analysis and SEM observation and the result indicated the ability of this fungus for pretreatment. A study on enzymatic hydrolysis resulted in an increased sugar yield of 27.67% as compared with untreated rubberwood (2.88%). The maximum ethanol concentration and yield were 17.9 g/L and 53% yield, respectively, after 120 hours. The results obtained demonstrate that rubberwood pretreated byC. subvermisporacan be used as an alternative material for the enzymatic hydrolysis and bioethanol production.

Catalytic Pyrolysis of Shenhua Coal to Prepare Fuel Gases Using Metallic Oxide Supported Catalysts

2012 ◽  
Vol 443-444 ◽  
pp. 1084-1090
Author(s):  
Zhan Ying Guo ◽  
Rong Ran ◽  
Xin Qian Shu ◽  
Ying Ying Yuan ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Temperature ◽  
Catalytic Pyrolysis ◽  
Supported Catalysts ◽  
Positive Influence ◽  
Metallic Oxide ◽  
Medium Temperature ◽  
Strong Adsorption ◽  
Series Of Experiments ◽  
The Individual

In order to study the catalytic activity in the preparation of fuel gases from catalytic pyrolysis of coal, the author selects NixOy/γ-Al2O3、CrxOy/γ-Al2O3，AgxOy/γ-Al2O3 and CoxOy/γ-Al2O3, respectively as the metal oxide supported catalysts from the previous experiment’s results. These catalysts have been added to Shenhua coal for a series of experiments. After these experiments, GC (gas chromatography) has been used for the analysis on the yield changes of CO and CH4 which result from the experiments. The results show that all of these catalysts have a positive influence on the yield of CO and CH4. As to the yield of CO, catalytic activity of CrxOy/γ-Al2O3 represents the most prominent performance at medium temperature period and CoxOy/γ-Al2O3 represents the same performance at high temperature period, while NixOy/γ-Al2O3, in which a great number of aluminum acid nickel spinels are reduced into metallic Ni at high temperature period, which results in different catalytic activity center from raw metallic Ni reduced from NiO. Consequently, the former reduced Ni shows outstanding catalytic activity. As to the yield of CH4, four catalysts mentioned above represent either the similar catalytic activity with CO or the individual characteristic —on one hand ,due to the strong adsorption of AgO and CrO3, CH4 gas is changed into H2 via pyrolysis at medium temperature as the yield of CH4 slumps ,on the other hand, due to an enormous amount of H2 production ,there is a drastically chemical reaction between H2 and these catalysts at high temperature, in which the yield of CH4 upswings toward the maximum amount greatly at the same time. Therefore, CrxOy/γ-Al2O3, AgxOy/γ-Al2O3 and CoxOy/γ-Al2O3 are more efficient at medium temperature and high temperature respectively. However, NixOy/γ-Al2O3 demonstrates the positive influence only from 800°Con. All of these results depend on the essence of catalysts to some extent. The study would have some theoretical guidance about increasing the utilization of coal and about industrial application of fuel gases generated from catalytic pyrolysis of coal.

A Study of Biodegradable Superabsorbent Materials Based on Acrylonitrile Grafted Sodium Alginate

2005 ◽  
Vol 277-279 ◽  
pp. 450-454 ◽  
Author(s):  
Young Hee Lee ◽  
Jung Soo Kim ◽  
Han Do Kim
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sodium Alginate ◽  
Graft Copolymer ◽  
Graft Copolymerization ◽  
Water Absorbency ◽  
Grafted Copolymer ◽  
Subsequent Hydrolysis ◽  
Maximum Water ◽  
Hydrolysis Conditions ◽  
Hydrolysis Of

Biodegradable superabsorbents, hydrolyzed AN(acrylonitrile)-grafted-SA(sodium alginate) copolymers were prepared in this study by graft copolymerization of acrylonitrile on sodium alginate and the subsequent hydrolysis of the resulting grafted copolymer. The absorbency was found to significantly depend on the % add-on, graft copolymerization conditions and hydrolysis conditions. The optimum condition for graft copolymerization to obtain the maximum % add-on (64.5%) was 4g SA, 12g AN, and 8.42g H2O2 in 100ml water at 70 oC for 10hr., respectively. The optimum hydrolysis conditions for the graft copolymer (64.5 % add-on) to reach the maximum water absorbency (2518g/g), saline absorbency (1558g/g), and WRV (288g/g) is 1g graft copolymer in 10 ml aqueous NaOH (1.0N) at 110 oC for 1 hr. Furthermore, this hydrolyzed AN-graft-SA showed a good biodegradability in enzymatic hydrolysis tests when compared with commercial superabsorbent materials.

scholarly journals Occurrence of abnormally cooked rice and water uptake by polished rice at high temperature.

1990 ◽  
Vol 43 (3) ◽  
pp. 215-220
Author(s):  
Aijiro YAMAMOTO ◽  
Hiroshi NAKAJIMA ◽  
Naoko TANIDA
Keyword(s):  
High Temperature ◽  
Water Uptake ◽  
Cooked Rice ◽  
Polished Rice
Sign in / Sign up

Export Citation Format

Share Document