High yield and high concentration glucose production from corncob residues after tetrahydrofuran + H2O co-solvent pretreatment and followed by enzymatic hydrolysis

2020 ◽  
Vol 132 ◽  
pp. 110107
Author(s):  
Fengpei Yao ◽  
Fei Shen ◽  
Xue Wan ◽  
Changwei Hu
Keyword(s):  
Enzymatic Hydrolysis ◽  
Glucose Production ◽  
High Yield ◽  
High Concentration

scholarly journals Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Molecular Structures ◽  
High Yield ◽  
Kinetic Control ◽  
High Concentration ◽  
Weak Association ◽  
Quantitative Synthesis ◽  
Thermodynamic Stabilization ◽  
Discrete Structures ◽  
Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

Process Evaluation of Enzymatic Hydrolysis with Filtrate Recycle for the Production of High Concentration Sugars

2011 ◽  
Vol 166 (4) ◽  
pp. 839-855 ◽  
Author(s):  
Ying Xue ◽  
Jannov Rusli ◽  
Hou-min Chang ◽  
Richard Phillips ◽  
Hasan Jameel
Keyword(s):  
Enzymatic Hydrolysis ◽  
Process Evaluation ◽  
High Concentration

scholarly journals A Novel Inulin-Mediated Ethanol Precipitation Method for Separating Endo-Inulinase From Inulinases for Inulooligosaccharides Production From Inulin

2021 ◽  
Vol 9 ◽  
Author(s):  
Xin Li ◽  
Qiannan Zhang ◽  
Wei Wang ◽  
Shang-Tian Yang
Keyword(s):  
Enzymatic Hydrolysis ◽  
Aspergillus Niger ◽  
Functional Food ◽  
Degree Of Polymerization ◽  
Precipitation Method ◽  
High Yield ◽  
Process Conditions ◽  
Food Ingredients ◽  
Ethanol Precipitation ◽  
Novel Method

Inulin is a kind of polysaccharide that can be obtained various biomass. Inulooligosaccharides (IOS), a kind of oligosaccharides that can be obtained from inulin by enzymatic hydrolysis using inulinases, have been regarded as the functional food ingredients. Commercially available inulinases produced by natural Aspergillus niger contained both endo- and exo-inulinase activities. For IOS production from inulin, it is desirable to use only endo-inulinase as exo-inulinase would produce mainly the monosacchairde fructose from inulin. In the present study, a simple inulin-mediated ethanol precipitation method was developed to separate endo- and exo-inulinases present in natural inulinases. IOS production from inulin using the enriched endo-inulinase was then optimized in process conditions including pH and temperature, achieving a high yield of ∼94%. The resultant IOS products had a degree of polymerization ranging from 2 to 7. The study demonstrated a novel method for obtaining partially purified or enriched endo-inulinase for IOS production from inulin in an efficient process.

scholarly journals Production of Cellulosic Ethanol from Enzymatically Hydrolysed Wheat Straws

2020 ◽  
Vol 10 (21) ◽  
pp. 7638
Author(s):  
Vasile-Florin Ursachi ◽  
Gheorghe Gutt
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Cellulosic Ethanol ◽  
Raw Material ◽  
High Yield ◽  
Liquid Ratio ◽  
Hydrolysis Process ◽  
Pretreatment Conditions ◽  
Pretreated Wheat Straw ◽  
First Time

The aim of this study is to find the optimal pretreatment conditions and hydrolysis in order to obtain a high yield of bioethanol from wheat straw. The pretreatments were performed with different concentrations of sulphuric acid 1, 2 and 3% (v/v), and were followed by an enzymatic hydrolysis that was performed by varying the solid-to-liquid ratio (1/20, 1/25 and 1/30 g/mL) and the enzyme dose (30/30 µL/g, 60/60 µL/g and 90/90 µL/g Viscozyme® L/Celluclast® 1.5 L). This mix of enzymes was used for the first time in the hydrolysis process of wheat straws which was previously pretreated with dilute sulfuric acid. Scanning electron microscopy indicated significant differences in the structural composition of the samples because of the pretreatment with H2SO4 at different concentrations, and ATR-FTIR analysis highlighted the changes in the chemical composition in the pretreated wheat straw as compared to the untreated one. HPLC-RID was used to identify and quantify the carbohydrates content resulted from enzymatic hydrolysis to evaluate the potential of using wheat straws as a raw material for production of cellulosic ethanol in Romania. The highest degradation of lignocellulosic material was obtained in the case of pretreatment with 3% H2SO4 (v/v), a solid-to-liquid ratio of 1/30 and an enzyme dose of 90/90 µL/g. Simultaneous saccharification and fermentation were performed using Saccharomyces cerevisiae yeast, and for monitoring the fermentation process a BlueSens equipment was used provided with ethanol, O2 and CO2 cap sensors mounted on the fermentation flasks. The highest concentration of bioethanol was obtained after 48 h of fermentation and it reached 1.20% (v/v).

Production with a High Yield of Bacterial Cellulose Nanocrystals by Enzymatic Hydrolysis

2019 ◽  
Vol 19 (03) ◽  
pp. 1950015
Author(s):  
Ricardo Brandes ◽  
Leticia de Souza ◽  
Claudimir Carminatti ◽  
Derce Recouvreux
Keyword(s):  
Enzymatic Hydrolysis ◽  
Bacterial Cellulose ◽  
Cellulose Nanocrystals ◽  
Primary Objective ◽  
High Yield ◽  
Low Density ◽  
Enzymatic Method ◽  
Citrate Buffer ◽  
Cellulose Hydrogel ◽  
Time Required

Bacterial cellulose nanocrystals are highly crystalline structures with nanoscopic scale dimensions that have received increased attention in the nanocomposites area. Its properties, such as large surface area, low density, mechanical strength and ease of modification, are attractive to the preparation many kinds of nanomaterials applied multifunctional in various fields. Besides, the cellulose nanocrystals are from abundant and renewable sources that are biodegradable. An altemative method is to obtain bacterial cellulose nanocrystal by enzymatic hydrolysis because it is, less expensive, it does not use chemicals and it requires much less energy. In this sense, the primary objective of this study was to produce bacterial cellulose using glycerol as a carbon source and isolate nanocrystals from bacterial cellulose using the enzymatic hydrolysis. This study also investigated the yield of nanocrystals depending on the weight of the bacterial cellulose hydrogel, keeping constant some enzymes. The study shows us that the enzymatic method has the best performance when using cellulose hydrogel 2[Formula: see text]g to 40[Formula: see text][Formula: see text]L cellulase enzyme (endoglucanase) and 1[Formula: see text]mL of citrate buffer. Also, it was observed that the yield of nanocrystals decrease with increasing time required for the hydrolysis.

Heat pretreatment improves the enzymatic hydrolysis of granular corn starch at high concentration

2018 ◽  
Vol 64 ◽  
pp. 193-199 ◽  
Author(s):  
Haocun Kong ◽  
Xue Yang ◽  
Zhengbiao Gu ◽  
Zhaofeng Li ◽  
Li Cheng ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Starch ◽  
High Concentration ◽  
Heat Pretreatment ◽  
Hydrolysis Of

scholarly journals Production ofN-Acetyl-d-Neuraminic Acid by Use of an Efficient Spore Surface Display System

2011 ◽  
Vol 77 (10) ◽  
pp. 3197-3201 ◽  
Author(s):  
Xiaoman Xu ◽  
Chao Gao ◽  
Xifeng Zhang ◽  
Bin Che ◽  
Cuiqing Ma ◽  
...  
Keyword(s):  
Surface Display ◽  
Value Added ◽  
Neuraminic Acid ◽  
High Yield ◽  
Permeability Barrier ◽  
Chemical Production ◽  
High Concentration ◽  
Suitable Alternative ◽  
Content Type ◽  
Whole Cells

ABSTRACTProduction ofN-acetyl-d-neuraminic acid (Neu5Ac) via biocatalysis is traditionally conducted using isolated enzymes or whole cells. The use of isolated enzymes is restricted by the time-consuming purification process, whereas the application of whole cells is limited by the permeability barrier presented by the microbial cell membrane. In this study, a novel type of biocatalyst, Neu5Ac aldolase presented on the surface ofBacillus subtilisspores, was used for the production of Neu5Ac. Under optimal conditions, Neu5Ac at a high concentration (54.7 g liter−1) and a high yield (90.2%) was obtained under a 5-fold excess of pyruvate overN-acetyl-d-mannosamine. The novel biocatalyst system, which is able to express and immobilize the target enzyme simultaneously on the surface ofB. subtilisspores, represents a suitable alternative for value-added chemical production.

Development of Robust Batch-Fabrication Process for High Performance SThM Probe and Quantitative Performance Evaluation

2009 ◽  
Author(s):  
Kwangseok Hwang ◽  
Kyeongtae Kim ◽  
Jaehoon Chung ◽  
Ohmyoung Kwon ◽  
Byeonghee Lee ◽  
...  
Keyword(s):  
High Performance ◽  
Synergistic Effects ◽  
Fabrication Process ◽  
High Yield ◽  
High Concentration ◽  
Crystal Surfaces ◽  
Hard Mask ◽  
Batch Fabrication ◽  
Key Steps ◽  
Tip Radius

To guarantee the reproducibility, uniformity and high yield of the fabrication results even with the unavoidable disturbances during the process, the robustness of the batch fabrication process of SThM probes has been improved. First, the shape of the hard mask used for the anisotropic tip etching was redesigned to fit to certain crystal surfaces of silicon wafer so that the sharpness of the tip is kept for a while even after the hard mask falls apart during the bulk tip etch process. Second, the aspect ratio of the tip was maximized by utilizing high concentration KOH solution. Third, the uniformity of etch rate across the wafer was improved by using ultrasonic bath during the anisotropic wet tip etching step. Through the synergistic effects of the modifications of the key steps, the tip fabrication process has become very robust and uniform. Taking advantage of the robustness of the process, we reduced the tip radius of the SThM probe down to 50 nm and the diameter of the thermocouple junction located at the end of the tip to 100 nm. As a result, the sensitivity and the spatial resolution of the new probe were demonstrated to be improved more than two times.

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