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Wyniki wyszukiwania dla: lactose hydrolysis
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Beta-Galactosidases of Pseudoalteromonas sp. – Characteristics and application for lactose hydrolysis and galactopyranosides synthesis
PublikacjaBeta-galactosidase [EC 3.2.1.23] is an enzyme that catalyzes the hydrolysis of O-glycosidic linkages in galactosides. It has biotechnological applications in the dairy industry for the production of milk with a low content of lactose and galactooligosacharides for use in healthy food. The transgalactosylation activity of beta-galactosidase can be used in the synthesis of alkyl galactopyranosides. Due to the fact that conditions of...
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Immobilized preparation of cold-adapted and halotolerant Antarctic β-galactosidase as a highly stable catalyst in lactose hydrolysis
PublikacjaZimnolubna rekombinowana beta-galaktozydaza antarktycznej morskiej bakterii Pseudoalteromonas sp. 22b została immobilizowana na chitozanie za pomocą aldehydu glutarowego. Preparat immobilizowanego enzymu w przeciwieństwie do preparatu enzymu w buforze reakcyjnym nie był inhibowany przez glukozę. Immobilizacja enzymu wpłynęła na podwyższenie o 10°C optymalnej temperatury aktywności względem jego nieimmobilizowanego odpowiednika...
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Beta-galactosidases from a psychrotolerant Arthrobacter isolates and their potential use
PublikacjaEnzymes from extremophiles, especially psychrophiles and psychrotolerant microorganisms are currently intensively studied because of their unusual structural and functional properties. One of these enzymes is a cold-adapted - galactosidase (EC 3.2.1.23) which catalyzes the hydrolysis of - 1,4-glycosidic bonds in -galactosides. The most common - galactoside is lactose, a disaccharide which makes up 2-7% of milk. The majority of...
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A method for the production of D-tagatose using a recombinant Pichia pastoris strain secreting beta-D-galactosidase from Arthrobacter chlorophenolicus and a recombinant L-arabinose isomerase from Arthrobacter sp. 22c
PublikacjaD-Tagatose is a natural monosaccharide which can be used as a low-calorie sugar substitute in food, beverages and pharmaceutical products. It is also currently being tested as an anti-diabetic and obesity control drug. D-Tagatose is a rare sugar, but it can be manufactured by the chemical or enzymatic isomerization of D-galactose obtained by a beta-D-galactosidase-catalyzed hydrolysis of milk sugar lactose and the separation of...
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A novel cold-active beta-D-galactosidase from the Paracoccus sp. 32d - gene cloning, purification and characterization
PublikacjaBeta-D-galactosidase (EC 3.2.1.23) catalyze the hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides. Cold-active beta-D-galactosidases have recently become a focus of attention of researchers and dairy product manufactures owing to theirs ability to: (I) eliminate of lactose from refrigerated milk for people afflicted with lactose intolerance, (II) convert lactose to glucose and galactose which...
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Meiothermus ruber cells as β-galactosidase activity biocatalyst
PublikacjaThe current study allowed to establish the possibility of using whole cells of thermophilic bacteria Meiothermus ruber as a biocatalyst with β-galactosidase activity. β-galactosidases are used for hydrolysis of lactose as well as for oligosaccharides synthesis. The advantages of using whole bacterial cells catalysis is not only elimination of tedious, expensive protein isolation and/or purification but also stabilization of enzymes...
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Cold-Active beta-Galactosidases: Sources, Biochemical Properties and Their Biotechnological Potential
Publikacjabeta-D-Galactosidases have been studied extensively in terms of their application to a variety of industrial technologies. To date, considerable research efforts have been devoted to characterization of new cold-active beta-D-galactosidases which were isolated directly from selected species of bacteria and yeasts, as well as with the use of metagenomic approaches. This chapter will provide a review of current research towards cold-active...
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B-GALACTOSIDASE ARTHROBACTER SP. 32cB - OBTAINING THE GENE SEQUENCE, CONSTRUCTION OF THE EXPRESSION SYSTEM, BIOSYNTHESIS AND BIOCHEMICAL CHARACTERIZATION OF THE ENZYME
PublikacjaINTRODUCTION: β-Galactosidase is an enzyme which catalyzes the hydrolysis of O glycosidic bond in β-galactosides. Another activity of β galactosidase is a transglycosylation activity. The main industrial use of this protein is the hydrolysis of lactose in milk in a cooling conditions. Synthesis of galactooligosaccharides, which are mostly used as a prebiotics added to some foods or available as dietary supplements, is only one...
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THE GENE CLONING, OVEREXPRESSION, PURIFICATION AND BIOCHEMICAL CHARACTERISATION OF A NEW COLD-ADAPTED β–GALACTOSIDASE FROM ARTHROBACTER SP. VII-4
PublikacjaINTRODUCTION. β-Galactosidase [EC 3.2.1.23] is an enzyme that catalyzes the hydrolysis of O-glycosidic linkages in galactosides. It is commercially used in dairy industry for the production of milk with reduced lactose content. Potentially, the best method for lactose removal under cooling conditions should be carried out with a cold-adapted enzyme. AIM. The aim of this study was to determine the taxonomic affiliation of the isolate...
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Structural studies of a cold-adapted dimeric Beta-D-galactosidase from Paracoccus sp. 32d
PublikacjaThe crystal structure of a novel dimeric [beta]-D-galactosidase from Paracoccus sp. 32d (Par[beta]DG) was solved in space group P212121 at a resolution of 2.4 Å by molecular replacement with multiple models using the BALBES software. This enzyme belongs to glycoside hydrolase family 2 (GH2), similar to the tetrameric and hexameric [beta]-D-galactosidases from Escherichia coli and Arthrobacter sp. C2-2, respectively. It is the second...
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Characterization of immobilized Escherichia coli cells transformed by β-galactosidase gene from Pyrococcus woesei
PublikacjaThermostable β-galactosidase from Escherichia coli transformant containing theenzyme gene from Pyrococcus woesei was immobilized on alginate gel.The benefits of using whole bacterial cells not only exclude expensive, laborious proteinisolation and purification but also stabilize enzymes by cytosol components. Increase inproductivity of enzyme can be achieved by cells permeabilization. To increase permeability ofcytoplasmic membrane...
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A novel cold-active β-D-galactosidase with transglycosylation activity from the Antarctic Arthrobacter sp. 32cB - gene cloning, purification and characterization
PublikacjaA gene encoding a novel β-D-galactosidase from the psychrotolerant Antarctic bacterium Arthrobacter sp. 32cB was isolated, cloned and expressed in Escherichia coli. The active form of recombinant β-D-galactosidase consists of two subunits with a combined molecular weight of approximately 257 kDa. The enzyme's maximum activity towards o-nitrophenyl-β-D-galactopyranoside was determined as occurring at 28 °C and pH 8.0. However, it...
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A new cold-adapted beta-D-galactosidase from the Antarctic Arthrobacter sp. 32c - gene cloning, overexpression, purification and properties
PublikacjaThe development of a new cold-active β-D-galactosidases and microorganisms that efficiently ferment lactose is of high biotechnological interest, particularly for lactose removal in milk and dairy products at low temperatures and for cheese whey bioremediation processes with simultaneous bio-ethanol production. In this article, we present a new β-D-galactosidase as a candidate to be applied in the above mentioned biotechnological...