scholarly journals Chemical and Enzymatic Hydrolysis of Polyurethane/Polylactide Blends

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Joanna Brzeska ◽  
Aleksandra Heimowska ◽  
Wanda Sikorska ◽  
Lidia Jasińska-Walc ◽  
Marek Kowalczuk ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Phosphate Buffer ◽  
Water Sorption ◽  
Enzymatic Degradation ◽  
Polymer Chains ◽  
Oil Sorption ◽  
Chemical Hydrolysis ◽  
Soft Segments ◽  
Hydrolysis Of

Polyether-esterurethanes containing synthetic poly[(R,S)-3-hydroxybutyrate] (R,S-PHB) and polyoxytetramethylenediol in soft segments and polyesterurethanes with poly(ε-caprolactone) and poly[(R,S)-3-hydroxybutyrate] were blended with poly([D,L]-lactide) (PLA). The products were tested in terms of their oil and water absorption. Oil sorption tests of polyether-esterurethane revealed their higher response in comparison to polyesterurethanes. Blending of polyether-esterurethanes with PLA caused the increase of oil sorption. The highest water sorption was observed for blends of polyether-esterurethane, obtained with 10% of R,S-PHB in soft segments. The samples mass of polyurethanes and their blends were almost not changed after incubation in phosphate buffer and trypsin and lipase solutions. Nevertheless the molecular weight of polymers was significantly reduced after degradation. It was especially visible in case of incubation of samples in phosphate buffer what suggested the chemical hydrolysis of polymer chains. The changes of surface of polyurethanes and their blends, after incubation in both enzymatic solutions, indicated on enzymatic degradation, which had been started despite the lack of mass lost. Polyurethanes and their blends, contained more R,S-PHB in soft segments, were degraded faster.

scholarly journals Influence of Initial Alkalinity of Lignocellulosic Waste on Their Enzymatic Degradation

2014 ◽  
Vol 40 (2) ◽  
pp. 103-113
Author(s):  
Marcin Wołczyński ◽  
Marta Janosz-Rajczyk
Keyword(s):  
Enzymatic Hydrolysis ◽  
Enzymatic Degradation ◽  
Suspended Solids ◽  
Lignocellulosic Waste ◽  
Initial Exposure ◽  
Total Sugars ◽  
Physical Chemical ◽  
Effect Of Treatment ◽  
Hydrolysis Of ◽  
By Products

Abstract The presented results of research on the effectiveness of enzymatic hydrolysis of lignocellulosic waste, depending on their initial depolymerisation in alkaline medium were considered in the context of the possibility of their further use in the fermentation media focused on the recovery of energy in the form of molecular hydrogen. The aim of this study was to determine the appropriate dose and concentration of a chemical reagent, whose efficiency would be high enough to cause decomposition of the complex, but without an excessive production of by-products which could adversely affect the progress and effectiveness of the enzymatic hydrolysis and fermentation. The effect of treatment on physical-chemical changes of homogenates’ properties such as pH, COD, the concentration of monosaccharide and total sugars and the concentration of total suspended solids and volatile suspended solids was determined. The enzymatic decomposition of lignocellulosic complex was repeatedly more efficient if the sample homogenates were subjected to an initial exposure to NaOH. The degree of conversion of complex sugars into simple sugars during enzymatic hydrolysis of homogenates pre-alkalized to pH 11.5 and 12.0 was 83.3 and 84.2% respectively, which should be sufficient for efficient hydrogen fermentation process.

Effects of Enzymatic Hydrolysis Conditions on the Antioxidant Activity of Red Tilapia (Oreochromis spp.) Viscera Hydrolysates

2020 ◽  
Vol 21 (12) ◽  
pp. 1249-1258
Author(s):  
Cindy T. Sepúlveda ◽  
José E. Zapata
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Enzymatic Hydrolysis ◽  
Protein Concentration ◽  
Polynomial Equation ◽  
Degree Of Hydrolysis ◽  
Red Tilapia ◽  
Hydrolysis Conditions ◽  
Hydrolysis Of ◽  
By Products

Background: Fish is an essential source of nutrients for human nutrition due to the composition of proteins, vitamins, and minerals, among other nutrients. Enzymatic hydrolysis represents an alternative for the use of by-products of the aquaculture industry. Objective: We propose to evaluate the effect of stirring speed, temperature, and initial protein concentration on the degree of hydrolysis of proteins and antioxidant activity of red tilapia (Oreochromis spp.) viscera hydrolysates. Methods: The effect of stirring speed, temperature, and initial protein concentration on the degree of hydrolysis of proteins and antioxidant activity was evaluated using an experimental design that was adjusted to a polynomial equation. The hydrolysate was fractioned to determine the antioxidant activity of the fractions, and functional properties were also measured. Results: Stirring speed and protein concentration presented a statistically significant effect (p <0.05) on all the response variables. However, the temperature did not present a statistically significant effect on the degree of hydrolysis. Discussion: The best conditions of hydrolysis were stirring speed of 51.44 rpm, a temperature of 59.15°C, and the protein concentration of 10 g L-1. The solubility of the hydrolysate protein was high at different pH, and the hydrolysate fraction with the highest antioxidant activity has a molecular weight <1 kDa. Conclusion: The degree of hydrolysis and the biological activity of red tilapia viscera hydrolysates (Oreochromis spp.) are affected by temperature, substrate concentration, and stirring speed. The optimal conditions of hydrolysis allowed to obtain a hydrolysate with antioxidant activity are due to the peptides with low molecular weight.

scholarly journals CRYSTALLINE INORGANIC PYROPHOSPHATASE ISOLATED FROM BAKER'S YEAST

1952 ◽  
Vol 35 (3) ◽  
pp. 423-450 ◽  
Author(s):  
M. Kunitz
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Isoelectric Point ◽  
Calcium Ions ◽  
Baker’S Yeast ◽  
Thiamine Pyrophosphate ◽  
Inorganic Pyrophosphatase ◽  
Baker's Yeast ◽  
Inorganic Pyrophosphate ◽  
Hydrolysis Of

Crystalline inorganic pyrophosphatase has been isolated from baker's yeast. The crystalline enzyme is a protein of the albumin type with an isoelectric point near pH 4.8. Its molecular weight is of the order of 100,000. It contains about 5 per cent tyrosine and 3.5 per cent tryptophane. It is most stable at pH 6.8. The new crystalline protein acts as a specific catalyst for the hydrolysis of inorganic pyrophosphate into orthophosphate ions. It does not catalyze the hydrolysis of the pyrophosphate radical of such organic esters as adenosine di- and triphosphate, or thiamine pyrophosphate. Crystalline pyrophosphatase requires the presence of Mg, Co, or Mn ions as activators. These ions are antagonized by calcium ions. Mg is also antagonized by Co or Mn ions. The rate of the enzymatic hydrolysis of inorganic pyrophosphate is proportional to the concentration of enzyme and is a function of pH, temperature, concentration of substrate, and concentration of activating ion. The approximate conditions for optimum rate are: 40°C. and pH 7.0 at a concentration of 3 to 4 x 10–3 M Na4P2O7 and an equivalent concentration of magnesium salt. The enzymatic hydrolysis of Na4P2O7 or K4P2O7 proceeds to completion and is irreversible under the conditions at which hydrolysis is occurring. Details are given of the method of isolation of the crystalline enzyme.

Cellulose loading and water sorption value as important parameters for the enzymatic hydrolysis of cellulose

Cellulose ◽  
2013 ◽  
Vol 20 (3) ◽  
pp. 1109-1119 ◽  
Author(s):  
Thomas Stauner ◽  
Igor B. Silva ◽  
Omar A. El Seoud ◽  
Elisabete Frollini ◽  
Denise F. S. Petri
Keyword(s):  
Enzymatic Hydrolysis ◽  
Water Sorption ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

scholarly journals Enzymatic Hydrolysis of Marine Collagen and Fibrinogen Proteins in the Presence of Thrombin

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 208 ◽  
Author(s):  
Ludmila L. Semenycheva ◽  
Marfa N. Egorikhina ◽  
Victoria O. Chasova ◽  
Natalya B. Valetova ◽  
Yulia L. Kuznetsova ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Main Part ◽  
Room Temperature ◽  
A Value ◽  
Hydrolysis Products ◽  
Native Collagen ◽  
Before And After ◽  
Molecular Fraction ◽  
Hydrolysis Of

Enzymatic hydrolysis of native collagen and fibrinogen was carried out under comparable conditions at room temperature. The molecular weight parameters of proteins before and after hydrolysis by thrombin were monitored by gel-penetrating chromatography (GPC). An analysis of the experiment results shows that the molecular weight parameters of the initial fibrinogen (Fn) and cod collagen (CC) are very similar. High molecular CC decays within the first minute, forming two low molecular fractions. The main part (~80%) falls on the fraction with a value of Mw less than 10 kDa. The initial high molecular fraction of Fn with Mw ~320–340 kDa is not completely hydrolyzed even after three days of control. The presence of low molecular fractions with Mw ~17 and Mw ~10 kDa in the solution slightly increases within an hour and noticeably increases for three days. The destruction of macromolecules of high molecular collagen to hydrolysis products appears almost completely within the first minute mainly to the polymer with Mw ~10 kDa, and enzymatic hydrolysis of fibrinogen proceeds slower than that of collagen, but also mainly to the polymer with Mw ~10 kDa. Comparative photos of the surfaces of native collagen, fibrinogen and the scaffold based on them were obtained.

scholarly journals Surface Pitting on Nanofibrous Matrix as an Ultra- Sensitive Indicator for Enzymatic Hydrolysis of Crystalline Cellulose

2021 ◽  
Author(s):  
mikiko tsudome ◽  
Mikako Tachioka ◽  
Miwako Tsuda ◽  
Yoshihiro Takaki ◽  
Shigeru Deguchi
Keyword(s):  
Enzymatic Hydrolysis ◽  
Enzymatic Degradation ◽  
Synthetic Polymers ◽  
Water Soluble ◽  
Crystalline Cellulose ◽  
Optical Profilometry ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Reaction Proceeds ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

<p>Assaying enzymatic degradation of the water-insoluble substrate such as cellulose and synthetic polymers has remained technically challenging, primarily because only the surface of the substrate is accessible to the enzymes and the reaction proceeds very slowly compared with those of water-soluble substrates. Here we show an ultra-sensitive and semi-quantitative assay for enzymatic hydrolysis of cellulose. By combining nanofibrous matrices with piezo-driven inkjet printing and optical profilometry, enzymatic hydrolysis of less than 1 nanogram of crystalline cellulose was successfully quantified. Unprecedented genetic diversity of cellulase was revealed when the same principle was applied for elucidating microbial degradation of cellulose in the deep sea. This work demonstrates that truly interdisciplinary efforts, encompassing diverse disciplines from nanotechnology to microbiology, are crucial to address scientific and technological problems towards sustainability.<br></p>

scholarly journals Enzymatic hydrolysis of lupin protein isolates—Changes in the molecular weight distribution, technofunctional characteristics, and sensory attributes

2019 ◽  
Vol 7 (8) ◽  
pp. 2747-2759 ◽  
Author(s):  
Katharina Schlegel ◽  
Katharina Sontheimer ◽  
Andrea Hickisch ◽  
Ali Abas Wani ◽  
Peter Eisner ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Sensory Attributes ◽  
Protein Isolates ◽  
Lupin Protein ◽  
Hydrolysis Of

Aging Stability of Neoprene Latex. Relation between Cross-Linking and Hydrolysis of Allylic Chlorine

1955 ◽  
Vol 28 (2) ◽  
pp. 628-640
Author(s):  
D. E. Andersen ◽  
Peter Kovacic
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Active Sites ◽  
Film Structure ◽  
Polymer Chains ◽  
Active Chlorine ◽  
Cross Linking ◽  
Curing Conditions ◽  
Cross Links ◽  
Hydrolysis Of

Abstract Neoprene polymer chains are cross-linked between active chlorine sites on the chains. There are two types of active sites of different reactivity. It is necessary to use more vigorous curing conditions to actuate the less reactive chlorine. The polymer develops cross-links while aging as a latex as well as during cure, and the decline of tensile strength with latex age may be inversely correlated with the amount of cross-linking during aging. The decline of tensile strength can be prevented by compounding with bis (diethylthiocarbamyl) disulfide. The calculations of the swelling data are not so complete as might be desired, primarily because of difficulty of measuring and interpreting the molecular weight of high-conversion polymers and to some uncertainty in determining μ. It is felt that the qualitative observations are justified, and that they serve to define both the technically important effect of film structure on tensile strength and the mechanism of cure.

scholarly journals Enzymatic hydrolysis of whey proteins. II. Molecular-weight range

1994 ◽  
Vol 44 (4) ◽  
pp. 529-532 ◽  
Author(s):  
P. González- Tello ◽  
F. Camacho ◽  
E. Jurado ◽  
M. P. Páez ◽  
E. M. Guadix
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Whey Proteins ◽  
Molecular Weight Range ◽  
Weight Range ◽  
Hydrolysis Of
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