scholarly journals Effect of Pre-Corrected pH on the Carbohydrate Hydrolysis of Bamboo during Hydrothermal Pretreatment

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 612 ◽  
Author(s):  
Lingzhi Huang ◽  
Zeguang Yang ◽  
Mei Li ◽  
Zhaomeng Liu ◽  
Chengrong Qin ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
High Efficiency ◽  
Uv Spectroscopy ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Hydrothermal Pretreatment ◽  
Aryl Ether ◽  
Carbohydrate Hydrolysis ◽  
Theoretical Support ◽  
Effects Of Ph

To confirm the prospects for application of pre-corrected pH hydrothermal pretreatment in biorefineries, the effects of pH on the dissolution and degradation efficiency of carbohydrates were studied. The species composition of the hydrolysate was analyzed using high efficiency anion exchange chromatography and UV spectroscopy. The result showed that the greatest balance between the residual solid and total dissolved solids was obtained at pH 4 and 170 °C. Maximum recovery rates of cellulose and lignin were as expected, whereas hemicellulose had the least recovery rate. The hemicellulose extraction rate was 42.19%, and the oligomer form accounted for 93.39% of the product. The physicochemical properties of bamboo with or without pretreatment was characterized. Compared with the traditional hydrothermal pretreatment, the new pretreatment bamboo has higher fiber crystallinity and thermal stability. In the pretreatment process, the fracture of β-aryl ether bond was inhibited and the structural dissociation of lignin was reduced. The physicochemical properties of bamboo was protected while the hemicellulose was extracted efficiently. It provides theoretical support for the efficient utilization of all components of woody biomass.

Extracellular polysaccharides from suspension cultures of Nicotiana plumbaginifolia

2020 ◽  
Author(s):  
Ian Sims ◽  
A Bacic
Keyword(s):  
Uronic Acid ◽  
Cell Suspension Cultures ◽  
Anion Exchange Chromatography ◽  
Nicotiana Plumbaginifolia ◽  
Suspension Cultures ◽  
Exchange Chromatography ◽  
Arabinogalactan Protein ◽  
Extracellular Polysaccharides ◽  
Selective Precipitation ◽  
The Individual

The soluble polymers secreted by cell-suspension cultures of Nicotiana plumbaginifolia contained 78% carbohydrate, 6% protein and 4% inorganic material. The extracellular polysaccharides were separated into three fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7 and the individual polysaccharides in each fraction were then isolated by selective precipitation and enzymic treatment. Monosaccharide and linkage compositions were determined for each polysaccharide after reduction of uronic acid residues and the degree of esterification of the various uronic acid residues in each polysaccharide was determined concurrently with the linkage types. Six components were identified: an arabinoxyloglucan (comprising 34% of the total polysaccharide) and a galactoglucomannan (15%) in the unbound neutral fraction, a type II arabinogalactan (an arabinogalactan-protein, 11%) and an acidic xylan (3%) in the first bound fraction, and an arabinoglucuronomannan (11%) and a galacturonan (26%) in the second bound fraction. © 1995.

Correlation between protein desorption behavior and its adsorption enthalpy change in polymer grafted anion exchange chromatography

2021 ◽  
pp. 111853
Author(s):  
Joao Carlos Simoes-Cardoso ◽  
Nanako Hoshino ◽  
Yusuke Yoshimura ◽  
Chyi-Shin Chen ◽  
Cristina Dias-Cabral ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enthalpy Change ◽  
Adsorption Enthalpy

scholarly journals Enzymatic Synthesis and Characterization of Different Families of Chitooligosaccharides and Their Bioactive Properties

2021 ◽  
Vol 11 (7) ◽  
pp. 3212
Author(s):  
Noa Miguez ◽  
Peter Kidibule ◽  
Paloma Santos-Moriano ◽  
Antonio O. Ballesteros ◽  
Maria Fernandez-Lobato ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Characterization ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzymatic Production ◽  
Bioactive Properties ◽  
Substrate Properties ◽  
Chitin Hydrolysis

Chitooligosaccharides (COS) are homo- or hetero-oligomers of D-glucosamine (GlcN) and N-acetyl-D-glucosamine (GlcNAc) that can be obtained by chitosan or chitin hydrolysis. Their enzymatic production is preferred over other methodologies (physical, chemical, etc.) due to the mild conditions required, the fewer amounts of waste and its efficiency to control product composition. By properly selecting the enzyme (chitinase, chitosanase or nonspecific enzymes) and the substrate properties (degree of deacetylation, molecular weight, etc.), it is possible to direct the synthesis towards any of the three COS types: fully acetylated (faCOS), partially acetylated (paCOS) and fully deacetylated (fdCOS). In this article, we review the main strategies to steer the COS production towards a specific group. The chemical characterization of COS by advanced techniques, e.g., high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and MALDI-TOF mass spectrometry, is critical for structure–function studies. The scaling of processes to synthesize specific COS mixtures is difficult due to the low solubility of chitin/chitosan, the heterogeneity of the reaction mixtures, and high amounts of salts. Enzyme immobilization can help to minimize such hurdles. The main bioactive properties of COS are herein reviewed. Finally, the anti-inflammatory activity of three COS mixtures was assayed in murine macrophages after stimulation with lipopolysaccharides.

scholarly journals Enzymatic assay of d-mannose in serum

1997 ◽  
Vol 43 (3) ◽  
pp. 533-538 ◽  
Author(s):  
James R Etchison ◽  
Hudson H Freeze
Keyword(s):  
Bacillus Stearothermophilus ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzymatic Assay ◽  
Enzymatic Reactions ◽  
Reaction Products ◽  
Serum Samples ◽  
Healthy Human ◽  
Human Volunteers ◽  
Chromatography Step

Abstract We describe a new and improved enzymatic assay for determining the concentration of d-mannose in sera. Serum d-glucose is selectively converted to glucose-6 phosphate with the highly specific thermostable glucokinase (EC 2.7.1.2) from Bacillus stearothermophilus. The anionic reaction products and excess substrates are removed by a rapid and simple anion-exchange chromatography step in microcentrifuge spin columns. d-Mannose in the glucose-depleted sample is then assayed spectrophotometrically by using coupled enzymatic reactions. The quantitative elimination of glucose from the serum samples allowed the accurate and reproducible assay of serum mannose in the 0–200 μmol/L range. Recovery of mannose added to serum (5–200 μmol/L) was 94% ± 4.4%. The intraassay CV was 6.7% at 40 μmol/L mannose (n = 5; 39.6 ± 1.6 μmol/L) and 4.4% at 80 μmol/L (n = 11; 75.0 ± 1.8 μmol/L); the interassay CV at these concentrations was 12.2% (n = 7; 36.9 ± 2.1 μmol/L) and 9.8% (n = 7; 74.2 ± 2.7 μmol/L), respectively. Sera from 11 healthy human volunteers contained an average of 54.1 ± 11.9 μmol/L mannose (range 36–81 μmol/L).

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