scholarly journals ISOLATION AND PURIFICATION OF LACTASE FROM LACTOBACILLUS ACIDOPHILUS

2012 ◽  
Vol 15 (3) ◽  
pp. 65-72
Author(s):  
Linh Thi Van Nguyen ◽  
Dung Thi Thuy Nguyen ◽  
Lam Bich Tran
Keyword(s):  
Molecular Weight ◽  
Kinetic Parameters ◽  
Organic Solvents ◽  
Lactobacillus Acidophilus ◽  
Gel Permeation Chromatography ◽  
Galactosidase Activity ◽  
Isolation And Purification ◽  
Enzyme Recovery ◽  
Gel Permeation ◽  
Enzyme Isolation

The enzyme β-galactosidase (β-D-galactoside galactohydrolase, EC 3.2.1.23) commonly known as lactase, has important applications in the dairy industry. From culture of strain Lactobacillus acidophilus having high and stable β-galactosidase activity, the study of crude enzyme isolation were carried out by ultrasonical extraction and precipitation by neutral salts and organic solvents. Best precipitant was isopropanol with enzyme recovery 89,93%, and enzyme purity increased 4,5 folds. Further β-galactosidase purification was carried out using gel permeation chromatography on Ultrahydrogel 250 to increase purity in 14,3 folds. The molecular weight of β-galactosidase was 40 kDa. The purified enzyme had optimum activity at 40oC, pH 7 – 7,5 and kinetic parameters of Vmax and Km were 2,3 μmol/min and 0,73 mM.

Molecular Size of the Diapause Hormone of the Silkworm Bombyx mori

1976 ◽  
Vol 31 (3-4) ◽  
pp. 132-134 ◽  
Author(s):  
Ichiro Kubota ◽  
Minoru Isobe ◽  
Toshio Goto ◽  
Kinsaku Hasegawa
Keyword(s):  
Molecular Weight ◽  
Bombyx Mori ◽  
Organic Solvents ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Molecular Weights ◽  
Gel Permeation ◽  
Modified Peptides ◽  
Diapause Hormone ◽  
Silkworm Bombyx Mori

Abstract The diapause hormone (D H) responsible for arrested development of the silkworm Bombix mori consists of two active principles of peptide (A and B) . Since both hormones form aggregates in aqueous phases, the molecular weights were determined by gel permeation chromatography of Merckogel OR 6000 using methanol-dichloromethane mixture as the developing agent. Gramicidins and modified peptides soluble in the organic solvents were used as the standard markers for the molecular weight measurements of the hormones. The molecular weights of DH -A and -B are estimated to be 3300 ± 400 and 2000 ± 200, respectively.

Study on Structure and Tanning Properties of Copolymer of Resorcinol and 3,5-Dihydroxyl Benzoic Acid

2012 ◽  
Vol 487 ◽  
pp. 48-52
Author(s):  
Sheng Hua Lv ◽  
Gong Rui ◽  
Di Li
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Gel Permeation Chromatography ◽  
Radical Copolymerization ◽  
Mass Ratio ◽  
Monomer Composition ◽  
Chrome Tanning ◽  
Gel Permeation

The radical copolymerization of resorcinol (RSC) and 3,5-dihydroxyl benzoic (DHBA) was carried out in water by the initiator of horseradish (HRP)/H2O2. It was discussed that the effects of monomer composition on the properties of the copolymer. The best monomer mass ratio of RSC:DHBA was 60:40 and the shrink temperature can reached to 88.5oC. The tanning result indicated that the copolymer of RSC and DHPA has particularly excellent tanning properties and can be served as leather tannage substitute for chrome tanning materials. And also the mechanism of the HRP initiated copolymerization was proposed. The structure and molecular weight of the copolymer was characterized by Fourier Transform Infrared spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). The copolymer can be as tannage and retannage in making leather process. The results showed that it has excellent tanning properties and retanning effects.

scholarly journals Correlations between retention volume and molecular size parameters in gel permeation chromatography of small molecules

1975 ◽  
Vol 28 (1) ◽  
pp. 189 ◽  
Author(s):  
RA Shanks
Keyword(s):  
Molecular Weight ◽  
Small Molecules ◽  
Organic Molecules ◽  
Retention Volume ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Molar Volumes ◽  
Small Organic Molecules ◽  
Molecular Dimension ◽  
Gel Permeation

Gel permeation columns of Bio Beads S-X8 have been used to provide separation of oligomers and other small organic molecules. Results show successful separations up to molecular weight c. 600. The retention times of compounds have been correlated with the largest molecular dimension of the molecules and also with molar volumes.

Alternative Tanning Agent for Leather Industry from a Sustainable Source

2021 ◽  
Vol 116 (3) ◽  
Author(s):  
Cigdem Kilicarislan Ozkan ◽  
Hasan Ozgunay
Keyword(s):  
Molecular Weight ◽  
Corn Starch ◽  
Periodate Oxidation ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Leather Industry ◽  
Sodium Metaperiodate ◽  
Gel Permeation ◽  
Aldehyde Content

Dialdehyde starches with different aldehyde content from native corn starch were prepared by sodium periodate oxidation to be used as a tanning agent in leather making. For this purpose, native corn starch was oxidized with sodium metaperiodate in different molar ratios. After oxidation processes, the yields, solubility in water and aldehyde contents of the obtained dialdehyde starches were determined as well as structure characterizations by Proton Nuclear Magnetic Resonance Spectroscopy, Fourier Transform Infrared Spectroscopy and Gel Permeation Chromatography. Evaluating the gel permeation chromatography data, the dialdehyde starch samples which were thought to be in appropriate molecular weight/size to penetrate into skin fibers were selected to be used in the tanning process. Their tanning abilities were evaluated by investigating hydrothermal stabilities, filling and fiber isolation characteristics and physical properties determined by mechanical tests and organoleptically. From the evaluation of the results, it was revealed that sodium metaperiodate oxidized starches which have appropriate molecular weight and adequate aldehyde content has a remarkable tanning effect and can be utilized as a tanning agent with the advantages of not necessitating pickling process which means saving time and simplifying the production but more importantly offering an important advantage from an environmental point of view.

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