scholarly journals Enzymatic conversion of DL-.ALPHA.-amino-.EPSILON.-caprolactam into L-lysine. II. Hydrolysis of L-.ALPHA.-amino-.EPSILON.-caprolactam by yeasts.

1976 ◽  
Vol 40 (9) ◽  
pp. 1695-1698 ◽  
Author(s):  
Takashi FUKUMURA
Keyword(s):  
Enzymatic Conversion ◽  
Hydrolysis Of

β-Glucosidase: microbial production and effect on enzymatic hydrolysis of cellulose

1977 ◽  
Vol 23 (2) ◽  
pp. 139-147 ◽  
Author(s):  
D. Sternberg ◽  
P. Vuayakumar ◽  
E. T. Reese
Keyword(s):  
Enzymatic Hydrolysis ◽  
Liquid Culture ◽  
Enzyme System ◽  
Microbial Production ◽  
Enzymatic Conversion ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Black Aspergilli ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of ◽  
Predominant Product

The enzymatic conversion of cellulose is catalyzed by a multiple enzyme system. The Trichoderma enzyme system has been studied extensively and has insufficient β-glucosidase (EC 3.2.1.21) activity for the practical saccharification of cellulose. The black aspergilli (A. niger and A. phoenicis) were superior producers of β-glucosidase and a method for production of this enzyme in liquid culture is presented. When Trichoderma cellulase preparations are supplemented with β-glucosidase from Aspergillus during practical saccharifications, glucose is the predominant product and the rate of saccharification is significantly increased. The stimulatory effect of β-glucosidase appears to be due to the removal of inhibitory levels of cellobiose.

scholarly journals Isolation of Free Amino Acids via Enzymatic Hydrolysis of Tobacco-Derived F1 Protein

2018 ◽  
Vol 28 (4) ◽  
pp. 179-190
Author(s):  
Mehdi Ashraf-Khorassani ◽  
William M. Coleman ◽  
Michael F. Dube ◽  
Larry T. Taylor
Keyword(s):  
Amino Acids ◽  
Enzymatic Hydrolysis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Protein Concentration ◽  
Enzyme Concentration ◽  
Enzymatic Conversion ◽  
Reaction Conditions ◽  
Analytical Methodology ◽  
Hydrolysis Of

SummaryFree amino acids have been isolated via optimized enzymatic hydrolysis of F1 tobacco protein using two cationic resins (Amberlite IR120 and Dowex MAC-2). Optimized enzymatic conversions of the protein as a result of systematic variations in conditions (e.g., time, temperature, pH, enzyme type, enzyme concentration, anaerobic/aerobic environments, and protein concentration) employing commercially available enzymes, were consistently higher than 50% with qualitative amino acid arrays that were consistent with the known composition of tobacco F1 protein. Amberlite IR120 was shown to have a much higher efficiency and capacity for isolation of amino acids from standard solutions and from hydrolysate when compared with the results using Dowex MAC-2. Two columns packed with conditioned Amberlite IR120 (120 × 10 mm,12–15 g resin) and (200 × 25.4 mm, 60–65 g resin) were used to isolate two batches (2.5–3.0 mg and 13–15 mg) of free amino acids, respectively. A relatively inexpensive analytical methodology was developed for rapid analysis of the free amino acids contained within the enzyme hydrolysate. Commercially available enzymes, when employed in optimized reaction conditions, are very effective for enzymatic conversion of tobacco F1 protein to free amino acids.

scholarly journals Functional acidic ionic liquids as effective solvents for the fractionation of lignocelluloses

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4721-4732
Author(s):  
Shi Jia Dong ◽  
Bi Xian Zhang ◽  
Peng Zhang ◽  
Kun Yang Wu ◽  
Xin Miao He ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Lignin Degradation ◽  
Degradation Products ◽  
Reducing Sugar ◽  
Alkaline Extraction ◽  
Enzymatic Conversion ◽  
Acidic Ionic Liquids ◽  
Lignin Degradation Products ◽  
High Yields ◽  
Hydrolysis Of

There is increasing interest in the application of ionic liquids for the pretreatment and fractionation of lignocelluloses. In this study, a series of functional acidic ionic liquids (ILs) with various heterocyclic organic cations were synthesized. Corn stalks were successfully fractionated into lignin, hemicelluloses, and cellulose when ultrasonically pretreated with ILs at 70 °C for 3 h, and subsequently treated with alkaline extraction. High yields of IL-isolated lignin (18.3% to 19.6%) and (8.3% to 14.6%) were obtained using ILs in the absence and presence of water, respectively. The yield of cellulose ranged from 40.0 to 77.0% from IL treatments, whereas the yield of hemicelluloses ranged from 1.1% to 17.3%. Enzymatic hydrolysis of the isolated cellulose residual produced 89.2% to 94.9% reducing sugar with 77.8% to 86.1% glucose, which corresponded to 80.5% to 91.4% enzymatic conversion of cellulose. Syringol and vanillin were found as the main lignin degradation products.

Effects of pH and urea concentration on urea removal from dialysate by enzymatic conversion and gas absorption using a capillary hemodialyzer

1980 ◽  
Vol 3 (1) ◽  
pp. 36-40
Author(s):  
E. Pişkin ◽  
T.M.S. Chang
Keyword(s):  
Gas Phase ◽  
Ammonia Concentration ◽  
Urea Concentration ◽  
Gas Absorption ◽  
Free Ammonia ◽  
Enzymatic Conversion ◽  
Ph Values ◽  
Effects Of Ph ◽  
Hydrolysis Of ◽  
Free Ammonia Concentration

This paper reports the effects of initial urea concentrations and pH values on the performance of a capillary hemodialyzer for the removal of free ammonia (NH3) formed by enzymatic hydrolysis of urea. Air was chosen as the gas phase. NaOH was used for alkalinization of dialysate. It was shown that one of the most important parameters was free ammonia concentration. The degrees of alkalinization and the initial urea concentration, were also important. Although even without the addition of NaOH, about 42% of the initial urea can be removed in one hour.

scholarly journals Enzymatic Conversion of RBCs by α-N-Acetylgalactosaminidase from Spirosoma linguale

2019 ◽  
Vol 2019 ◽  
pp. 1-27
Author(s):  
Thomas J. Malinski ◽  
Harkewal Singh
Keyword(s):  
Recombinant Enzyme ◽  
Enzymatic Conversion ◽  
Free Living ◽  
A Cell ◽  
Hydrolysis Of

Spirosoma linguale is a free-living nonpathogenic organism. Like many other bacteria, S. linguale produces a cell-associated α-N-acetylgalactosaminidase. This work was undertaken to elucidate the nature of this activity. The recombinant enzyme was produced, purified, and examined for biochemical attributes. The purified enzyme was ~50 kDa active as a homodimer in solution. It catalyzed hydrolysis of α-N-acetylgalactosamine at pH 7. Calculated KM was 1.1 mM with kcat of 173 s−1. The described enzyme belongs to the GH109 family.

scholarly journals Recombinant α-NAcetylgalactosaminidase from Marine Bacterium-Modifying A Erythrocyte Antigens

Acta Naturae ◽  
2015 ◽  
Vol 7 (1) ◽  
pp. 117-120 ◽  
Author(s):  
L. A. Balabanova ◽  
V. А. Golotin ◽  
I. Yu. Bakunina ◽  
L. V. Slepchenko ◽  
V. V Isakov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
1H Nmr Spectroscopy ◽  
Marine Bacterium ◽  
Gel Filtration ◽  
Glycoside Hydrolases ◽  
Enzymatic Conversion ◽  
Metal Affinity ◽  
Escherichia Coli Cells ◽  
Serological Activity ◽  
Hydrolysis Of

A plasmid based on pET-40b was constructed to synthesize recombinant -N-acetylgalactosaminidase of the marine bacterium Arenibacter latericius KMM 426 T (-AlNaGal) in Escherichia coli cells. The yield of -Al-NaGal attains 10 mg/ml with activity of 49.7 1.3 U at 16C, concentration of inductor 2 mM, and cultivation for 12 h. Techniques such as anion exchange, metal affinity and gel filtration chromatography to purify -AlNaGal were applied. -AlNaGal is a homodimer with a molecular weight of 164 kDa. This enzyme is stable at up to 50C with a temperature range optimum activity of 20-37C. Furthermore, its activity is independent of the presence of metal ions in the incubation medium. 1H NMR spectroscopy revealed that -AlNaGal catalyzes the hydrolysis of the O-glycosidic bond with retention of anomeric stereochemistry and possesses a mechanism of action identical to that of other glycoside hydrolases of the 109 family. -AlNaGal reduces the serological activity of A erythrocytes at pH 7.3. This property of -AlNaGal can potentially be used for enzymatic conversion of A and AB erythrocytes to blood group O erythrocytes.

scholarly journals Using poly(N-Vinylcaprolactam) to Improve the Enzymatic Hydrolysis Efficiency of Phenylsulfonic Acid-Pretreated Bamboo

2021 ◽  
Vol 9 ◽  
Author(s):  
Xianqing Lv ◽  
Guangxu Yang ◽  
Zhenggang Gong ◽  
Xin Cheng ◽  
Li Shuai ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Hydrophobic Interactions ◽  
Practical Method ◽  
Tween 20 ◽  
Ionic Surfactant ◽  
Enzymatic Conversion ◽  
Chemical Pretreatment ◽  
Cellulose Accessibility ◽  
Negative Effect ◽  
Hydrolysis Of

Chemical pretreatment followed by enzymatic hydrolysis has been regarded as a viable way to produce fermentable sugars. Phenylsulfonic acid (PSA) pretreatment could efficiently fractionate the non-cellulosic components (hemicelluloses and lignin) from bamboo and result in increased cellulose accessibility that was 10 times that of untreated bamboo. However, deposited lignin could trigger non-productive adsorption to enzymes, which therefore significantly decreased the enzymatic hydrolysis efficiency of PSA-pretreated bamboo substrates. Herein, poly(N-vinylcaprolactam) (PNVCL), a non-ionic surfactant, was developed as a novel additive for overcoming the non-productive adsorption of lignin during enzymatic hydrolysis. PNVCL was found to be not only more effective than those of commonly used lignosulfonate and polyvinyl alcohol for overcoming the negative effect of lignin, but also comparable to the robust Tween 20 and bovine serum albumin additives. A PNVCL loading at 1.2 g/L during enzymatic hydrolysis of PSA pretreated bamboo substrate could achieve an 80% cellulosic enzymatic conversion and meanwhile reduce the cellulase loading by three times as compared to that without additive. Mechanistic investigations indicated that PNVCL could block lignin residues through hydrophobic interactions and the resultant PNVCL coating resisted the adsorption of cellulase via electrostatic repulsion and/or hydration. This practical method can improve the lignocellulosic enzymatic hydrolysis efficiency and thereby increase the productivity and profitability of biorefinery.

scholarly journals Insight into the Hydrolytic Selectivity of β-Glucosidase to Enhance the Contents of Desired Active Phytochemicals in Medicinal Plants

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Young Soo Kim ◽  
Jin Yeul Ma
Keyword(s):  
Substrate Specificity ◽  
Herbal Medicines ◽  
Glycoside Hydrolase Family ◽  
Enzymatic Conversion ◽  
Herbal Extracts ◽  
Acid Base ◽  
Pharmacologically Active ◽  
Hydrolysis Of ◽  
Hydrolase Family ◽  
Insight Into

Most glycosides in herbal medicines become pharmacologically active after hydrolysis or subsequent metabolism to respective aglycones. Hence, the hydrolytic efficiency of glycosidase is a crucial determinant of the pharmacological efficacy of herbal glycosides. In this study, we investigated the enzymatic conversion of the four herbal extracts and their glycosides using the glycoside hydrolase family 3 β-glucosidase from Lactobacillus antri (rBGLa). We show that β-glucosidase substrate specificity depends on the arrangements and linkage types of sugar residues in glycosides. The enzyme rBGLa showed higher hydrolytic selectivity for glucopyranoside than for glucuronide and rhamnopyranoside, and specificity for 1→6 rather than 1→2 linkages. In addition, in silico 3D structural models suggested that D243 and E426 of rBGLa act as catalytic nucleophile and acid/base residues, respectively. These experiments also suggested that substrate specificity is determined by interactions between the C6 residue of the sugar moiety of the substrate glycoside and the oxygen OD1 of D56 in rBGLa. Therefore, despite the broad substrate spectrum of β-glucosidase, differences in hydrolytic selectivity of β-glucosidases for glycoside structures could be exploited to enhance the hydrolysis of the desired medicinal glycosides in herbs using tailored β-glucosidases, allowing for improvement of specific potencies of herbal medicines.

scholarly journals Carbohydrate-binding modules targeting branched polysaccharides: overcoming side-chain recalcitrance in a non-catalytic approach

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jiawen Liu ◽  
Di Sun ◽  
Jingrong Zhu ◽  
Cong Liu ◽  
Weijie Liu
Keyword(s):  
Side Chain ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Enzymatic Conversion ◽  
Type Iii ◽  
Debranching Enzymes ◽  
Ligand Type ◽  
Carbohydrate Binding Modules ◽  
Hydrolysis Of ◽  
Main Strategy

AbstractExtensive decoration of backbones is a major factor resulting in resistance of enzymatic conversion in hemicellulose and other branched polysaccharides. Employing debranching enzymes is the main strategy to overcome this kind of recalcitrance at present. A carbohydrate-binding module (CBM) is a contiguous amino acid sequence that can promote the binding of enzymes to various carbohydrates, thereby facilitating enzymatic hydrolysis. According to previous studies, CBMs can be classified into four types based on their preference in ligand type, where Type III and IV CBMs prefer to branched polysaccharides than the linear and thus are able to specifically enhance the hydrolysis of substrates containing side chains. With a role in dominating the hydrolysis of branched substrates, Type III and IV CBMs could represent a non-catalytic approach in overcoming side-chain recalcitrance.

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

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