Relevant bibliographies by topics / Β-galactosidases

Academic literature on the topic 'Β-galactosidases'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Β-galactosidases"

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Kumar, Vijay, Nikhil Sharma, and Tek Chand Bhalla. "In Silico Analysis of β-Galactosidases Primary and Secondary Structure in relation to Temperature Adaptation." Journal of Amino Acids 2014 (March 24, 2014): 1–9. http://dx.doi.org/10.1155/2014/475839.

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β-D-Galactosidases (EC 3.2.1.23) hydrolyze the terminal nonreducing β-D-galactose residues in β-D-galactosides and are ubiquitously present in all life forms including extremophiles. Eighteen microbial β-galactosidase protein sequences, six each from psychrophilic, mesophilic, and thermophilic microbes, were analyzed. Primary structure reveals alanine, glycine, serine, and arginine to be higher in psychrophilic β-galactosidases whereas valine, glutamine, glutamic acid, phenylalanine, threonine, and tyrosine are found to be statistically preferred by thermophilic β-galactosidases. Cold active β-galactosidase has a strong preference towards tiny and small amino acids, whereas high temperature inhabitants had higher content of basic and aromatic amino acids. Thermophilic β-galactosidases have higher percentage of α-helix region responsible for temperature tolerance while cold loving β-galactosidases had higher percentage of sheet and coil region. Secondary structure analysis revealed that charged and aromatic amino acids were significant for sheet region of thermophiles. Alanine was found to be significant and high in the helix region of psychrophiles and valine counters in thermophilic β-galactosidase. Coil region of cold active β-galactosidase has higher content of tiny amino acids which explains their high catalytic efficiency over their counterparts from thermal habitat. The present study has revealed the preference or prevalence of certain amino acids in primary and secondary structure of psychrophilic, mesophilic, and thermophilic β-galactosidase.
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Møller, Peter L., Flemming Jørgensen, Ole C. Hansen, Søren M. Madsen, and Peter Stougaard. "Intra- and Extracellular β-Galactosidases fromBifidobacterium bifidum and B. infantis: Molecular Cloning, Heterologous Expression, and Comparative Characterization." Applied and Environmental Microbiology 67, no. 5 (May 1, 2001): 2276–83. http://dx.doi.org/10.1128/aem.67.5.2276-2283.2001.

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ABSTRACT Three β-galactosidase genes from Bifidobacterium bifidum DSM20215 and one β-galactosidase gene fromBifidobacterium infantis DSM20088 were isolated and characterized. The three B. bifidum β-galactosidases exhibited a low degree of amino acid sequence similarity to each other and to previously published β-galactosidases classified as family 2 glycosyl hydrolases. Likewise, the B. infantisβ-galactosidase was distantly related to enzymes classified as family 42 glycosyl hydrolases. One of the enzymes from B. bifidum, termed BIF3, is most probably an extracellular enzyme, since it contained a signal sequence which was cleaved off during heterologous expression of the enzyme in Escherichia coli. Other exceptional features of the BIF3 β-galactosidase were (i) the monomeric structure of the active enzyme, comprising 1,752 amino acid residues (188 kDa) and (ii) the molecular organization into an N-terminal β-galactosidase domain and a C-terminal galactose binding domain. The other two B. bifidumβ-galactosidases and the enzyme from B. infantis were multimeric, intracellular enzymes with molecular masses similar to typical family 2 and family 42 glycosyl hydrolases, respectively. Despite the differences in size, molecular composition, and amino acid sequence, all four β-galactosidases were highly specific for hydrolysis of β-d-galactosidic linkages, and all four enzymes were able to transgalactosylate with lactose as a substrate.
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Pressey, Russell, and C. M. Sean Carrington. "β-Galactosidase II in Ripening Tomatoes." HortScience 30, no. 4 (July 1995): 817A—817. http://dx.doi.org/10.21273/hortsci.30.4.817a.

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Tomatoes contain several isozymes of β-galactosidase, but only one, β-galactosidase II, can hydrolyze the β-1,4-galactans in tomato cell walls. β-galactosidase II has now been highly purified by modification of the original procedure. The molecular weight of this isozyme is ≈62 kDa according to gel infiltration, but SDS-PAGE of the purified enzyme separated three components with molecular weights of 29, 42, and 82 kDa. The 82-kDa peptide may be the intact enzyme and the smallest peptides are subunits as proposed for other β-galactosidases. The N-terminal amino acid sequence of β-galactosidase II showed high homology with amino acid sequences reported for other plant β-galactosidases. A new assay for β-galactosidase II in tomato extracts has been developed using FPLC. This isozyme was not detected in mature-green tomatoes but appeared at about the breaker stage and increased during ripening. The increase in b-galactosidase II was accompanied by a decrease in galactose content of cell wall polysaccharides, suggesting that this enzyme may be involved in the loss of galactose during tomato ripening.
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Núñez-Montero, Kattia, Rodrigo Salazar, Andrés Santos, Olman Gómez-Espinoza, Scandar Farah, Claudia Troncoso, Catalina Hoffmann, Damaris Melivilu, Felipe Scott, and Leticia Barrientos Díaz. "Antarctic Rahnella inusitata: A Producer of Cold-Stable β-Galactosidase Enzymes." International Journal of Molecular Sciences 22, no. 8 (April 16, 2021): 4144. http://dx.doi.org/10.3390/ijms22084144.

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There has been a recent increase in the exploration of cold-active β-galactosidases, as it offers new alternatives for the dairy industry, mainly in response to the current needs of lactose-intolerant consumers. Since extremophilic microbial compounds might have unique physical and chemical properties, this research aimed to study the capacity of Antarctic bacterial strains to produce cold-active β-galactosidases. A screening revealed 81 out of 304 strains with β-galactosidase activity. The strain Se8.10.12 showed the highest enzymatic activity. Morphological, biochemical, and molecular characterization based on whole-genome sequencing confirmed it as the first Rahnella inusitata isolate from the Antarctic, which retained 41–62% of its β-galactosidase activity in the cold (4 °C–15 °C). Three β-galactosidases genes were found in the R. inusitata genome, which belong to the glycoside hydrolase families GH2 (LacZ and EbgA) and GH42 (BglY). Based on molecular docking, some of these enzymes exhibited higher lactose predicted affinity than the commercial control enzyme from Aspergillus oryzae. Hence, this work reports a new Rahnella inusitata strain from the Antarctic continent as a prominent cold-active β-galactosidase producer.
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Eda, Masahiro, Megumi Ishimaru, and Toshiji Tada. "Expression, purification, crystallization and preliminary X-ray crystallographic analysis of tomato β-galactosidase 4." Acta Crystallographica Section F Structural Biology Communications 71, no. 2 (January 28, 2015): 153–56. http://dx.doi.org/10.1107/s2053230x14027800.

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Plant β-galactosidases play important roles in carbohydrate-reserve mobilization, cell-wall expansion and degradation, and turnover of signalling molecules during ripening. Tomato β-galactosidase 4 (TBG4) not only has β-galactosidase activity but also has exo-β-(1,4)-galactanase activity, and prefers β-(1,4)-galactans longer than pentamers as its substrates; most other β-galactosidases only have the former activity. Recombinant TBG4 protein expressed in the yeastPichia pastoriswas crystallized by the sitting-drop vapour-diffusion method using PEG 10 000 as a precipitant. The crystals belonged to the orthorhombic space groupP212121, with unit-parametersa= 92.82,b= 96.30,c= 159.26 Å, and diffracted to 1.65 Å resolution. Calculation of the Matthews coefficient suggested the presence of two monomers per asymmetric unit (VM= 2.2 Å3 Da−1), with a solvent content of 45%.
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Dutra Rosolen, Michele, Adriano Gennari, Giandra Volpato, and Claucia Fernanda Volken de Souza. "Lactose Hydrolysis in Milk and Dairy Whey Using Microbial β-Galactosidases." Enzyme Research 2015 (October 26, 2015): 1–7. http://dx.doi.org/10.1155/2015/806240.

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This work aimed at evaluating the influence of enzyme concentration, temperature, and reaction time in the lactose hydrolysis process in milk, cheese whey, and whey permeate, using two commercial β-galactosidases of microbial origins. We used Aspergillus oryzae (at temperatures of 10 and 55°C) and Kluyveromyces lactis (at temperatures of 10 and 37°C) β-galactosidases, both in 3, 6, and 9 U/mL concentrations. In the temperature of 10°C, the K. lactis β-galactosidase enzyme is more efficient in the milk, cheese whey, and whey permeate lactose hydrolysis when compared to A. oryzae. However, in the enzyme reaction time and concentration conditions evaluated, 100% lactose hydrolysis was not reached using the K. lactis β-galactosidase. The total lactose hydrolysis in whey and permeate was obtained with the A. oryzae enzyme, when using its optimum temperature (55°C), at the end of a 12 h reaction, regardless of the enzyme concentration used. For the lactose present in milk, this result occurred in the concentrations of 6 and 9 U/mL, with the same time and temperature conditions. The studied parameters in the lactose enzymatic hydrolysis are critical for enabling the application of β-galactosidases in the food industry.
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Ferreira-Lazarte, Alvaro, F. Javier Moreno, and Mar Villamiel. "Application of a commercial digestive supplement formulated with enzymes and probiotics in lactase non-persistence management." Food & Function 9, no. 9 (2018): 4642–50. http://dx.doi.org/10.1039/c8fo01091a.

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Strategies to avoid lactose malabsorption, which affects 70% of the world's population, are focused on the restriction of milk and dairy products or the use of non-human β-galactosidases or probiotics endowed with β-galactosidase activity added at mealtime.
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Pham, Mai-Lan, Anh-Minh Tran, Suwapat Kittibunchakul, Tien-Thanh Nguyen, Geir Mathiesen, and Thu-Ha Nguyen. "Immobilization of β-Galactosidases on the Lactobacillus Cell Surface Using the Peptidoglycan-Binding Motif LysM." Catalysts 9, no. 5 (May 12, 2019): 443. http://dx.doi.org/10.3390/catal9050443.

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Lysin motif (LysM) domains are found in many bacterial peptidoglycan hydrolases. They can bind non-covalently to peptidoglycan and have been employed to display heterologous proteins on the bacterial cell surface. In this study, we aimed to use a single LysM domain derived from a putative extracellular transglycosylase Lp_3014 of Lactobacillus plantarum WCFS1 to display two different lactobacillal β-galactosidases, the heterodimeric LacLM-type from Lactobacillus reuteri and the homodimeric LacZ-type from Lactobacillus delbrueckii subsp. bulgaricus, on the cell surface of different Lactobacillus spp. The β-galactosidases were fused with the LysM domain and the fusion proteins, LysM-LacLMLreu and LysM-LacZLbul, were successfully expressed in Escherichia coli and subsequently displayed on the cell surface of L. plantarum WCFS1. β-Galactosidase activities obtained for L. plantarum displaying cells were 179 and 1153 U per g dry cell weight, or the amounts of active surface-anchored β-galactosidase were 0.99 and 4.61 mg per g dry cell weight for LysM-LacLMLreu and LysM-LacZLbul, respectively. LysM-LacZLbul was also displayed on the cell surface of other Lactobacillus spp. including L. delbrueckii subsp. bulgaricus, L. casei and L. helveticus, however L. plantarum is shown to be the best among Lactobacillus spp. tested for surface display of fusion LysM-LacZLbul, both with respect to the immobilization yield as well as the amount of active surface-anchored enzyme. The immobilized fusion LysM-β-galactosidases are catalytically efficient and can be reused for several repeated rounds of lactose conversion. This approach, with the β-galactosidases being displayed on the cell surface of non-genetically modified food-grade organisms, shows potential for applications of these immobilized enzymes in the synthesis of prebiotic galacto-oligosaccharides.
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Rutkiewicz-Krotewicz, Maria, Agnieszka J. Pietrzyk-Brzezinska, Bartosz Sekula, Hubert Cieśliński, Anna Wierzbicka-Woś, Józef Kur, and Anna Bujacz. "Structural studies of a cold-adapted dimeric β-D-galactosidase fromParacoccussp. 32d." Acta Crystallographica Section D Structural Biology 72, no. 9 (August 31, 2016): 1049–61. http://dx.doi.org/10.1107/s2059798316012535.

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The crystal structure of a novel dimeric β-D-galactosidase fromParacoccussp. 32d (ParβDG) was solved in space groupP212121at a resolution of 2.4 Å by molecular replacement with multiple models using theBALBESsoftware. This enzyme belongs to glycoside hydrolase family 2 (GH2), similar to the tetrameric and hexameric β-D-galactosidases fromEscherichia coliandArthrobactersp. C2-2, respectively. It is the second known structure of a cold-active GH2 β-galactosidase, and the first in the form of a functional dimer, which is also present in the asymmetric unit. Cold-adapted β-D-galactosidases have been the focus of extensive research owing to their utility in a variety of industrial technologies. One of their most appealing applications is in the hydrolysis of lactose, which not only results in the production of lactose-free dairy, but also eliminates the `sandy effect' and increases the sweetness of the product, thus enhancing its quality. The determined crystal structure represents the five-domain architecture of the enzyme, with its active site located in close vicinity to the dimer interface. To identify the amino-acid residues involved in the catalytic reaction and to obtain a better understanding of the mechanism of action of this atypical β-D-galactosidase, the crystal structure in complex with galactose (ParβDG–Gal) was also determined. The catalytic site of the enzyme is created by amino-acid residues from the central domain 3 and from domain 4 of an adjacent monomer. The crystal structure of this dimeric β-D-galactosidase reveals significant differences in comparison to other β-galactosidases. The largest difference is in the fifth domain, named Bgal_windup domain 5 inParβDG, which contributes to stabilization of the functional dimer. The location of this domain 5, which is unique in size and structure, may be one of the factors responsible for the creation of a functional dimer and cold-adaptation of this enzyme.
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Thoma, Julia, David Stenitzer, Reingard Grabherr, and Erika Staudacher. "Identification, Characterization, and Expression of a β-Galactosidase from Arion Species (Mollusca)." Biomolecules 12, no. 11 (October 27, 2022): 1578. http://dx.doi.org/10.3390/biom12111578.

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β-Galactosidases (β-Gal, EC 3.2.1.23) catalyze the cleavage of terminal non-reducing β-D-galactose residues or transglycosylation reactions yielding galacto-oligosaccharides. In this study, we present the isolation and characterization of a β-galactosidase from Arion lusitanicus, and based on this, the cloning and expression of a putative β-galactosidase from Arion vulgaris (A0A0B7AQJ9) in Sf9 cells. The entire gene codes for a protein consisting of 661 amino acids, comprising a putative signal peptide and an active domain. Specificity studies show exo- and endo-cleavage activity for galactose β1,4-linkages. Both enzymes, the recombinant from A. vulgaris and the native from A. lusitanicus, display similar biochemical parameters. Both β-galactosidases are most active in acidic environments ranging from pH 3.5 to 4.5, and do not depend on metal ions. The ideal reaction temperature is 50 °C. Long-term storage is possible at up to +4 °C for the A. vulgaris enzyme, and at up to +20 °C for the A. lusitanicus enzyme. This is the first report of the expression and characterization of a mollusk exoglycosidase.
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Dissertations / Theses on the topic "Β-galactosidases"

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Goulas, Theodoros K. "Biological and biotechnological aspects of β- and α-galactosidases from Bifidobacterium bifidum ncimb41171." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494990.

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In this thesis, the field of the bifidobacteria! physiology in relation to β- and α-galactosidases is described and perspectives of them for oligosaccharides synthesis are discussed- The experimental work focused on the isolation and characterisation of these cell constituents from Bifidobacterium bifidum NCIMB41171. To generate a basis for subsequent work the construction of a genomic DNA library was carried out. This resulted in the isolation of four different β-galactosidases (bbgI, bbgII, bbgIII and bbgIV) and one α-galactosidase (melA) genes. Molecular characterisation of the gene products indicated their putative location, which was subsequently confirmed after expression in an E. coli host. Nucleotide and amino acid sequence comparisons with other known bifidobacterial enzymes revealed aspects of either their evolution or conservation among species.
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Attal, Sandra. "Utilisation des enzymes en chimie organique : application à la synthèse d'esters de dipeptides par la papai͏̈ne et de galactosyl-sérines par les α-et β-galactosidases." Paris 5, 1992. http://www.theses.fr/1992PA05P614.

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Yates, Francesca Jo. "Towards novel luminescent probes for monitoring β- galactosidase activity." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1376/.

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This thesis describes efforts made towards the synthesis of a biologically stable, luminescent molecular probe, which could be used to investigate in vivo the processing of sugars by β-galactosidases. To this end, a lactose-based probe was designed, featuring a Lanthanide held within a chelate and appended to the glucosyl unit, and a proximal naphthyl moiety, attached to the galactose unit, which would function as a sensitiser for luminescence. A β-galactosidase enzyme from B. circulans was chosen to carry out the investigation. A number of novel methyl glucosides, functionalised with a naphthyl moiety at C6 of the sugar, were prepared. These were then used as glycosyl acceptors to make disaccharides (lactose analogues), with the enzyme (functioning in reverse) catalysing the glycosylation. The enzymatic reaction was optimised by varying the amount of enzyme, the reaction pH, the ratio of glycosyl acceptor to donor, the reaction temperature, concentration and solvent mixture. The optimal conditions were found to be a 0.4 M reaction solution at pH 7.0 with 20% acetonitrile, a 7:1 ratio of glycosyl acceptor to donor, 19.6 U of enzyme per mmol of acceptor, and a reaction temperature of 30°C. The resulting disaccharide products exhibited unusual regioselectivity for the β-galactosidase from B. circulans, with unexpected β(1→3) and β(1→2) glycosidic linkages being formed. In an effort to increase the efficiency of the process of identifying suitable substrates for the enzyme, a dynamic combinatorial chemistry approach was also explored. This used disulfide bonds to attach the naphthyl moiety to the methyl glucoside using linkers of different lengths. From this library, the enzyme successfully processed the novel disulfide GlcOMe-S-S-CH\(_2\)Np as a glycosyl acceptor with p-nitrophenyl galactose as the glycosyl donor. This resulted in a novel disaccharide featuring a naphthyl group attached via a disulfide bond to the glucosidic residue.
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Pavel-Licsandru, Ileana-Alexandra. "Silica based materials for the encapsulation of β-Galactosidase." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0322/document.

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L’ingénierie des compléments alimentaires solides offre plusieurs avantages dans la formulation industrielle des produits alimentaires, en termes de production, stockage, et manipulation. Pour ces raisons, l’objectif de cette thèse était d’élaborer des ‘cargos’ bio-réactifs, permettant l’encapsulation d’une enzyme exogène capable de réaliser la réaction d’hydrolyse des molécules de lactose. Aujourd’hui il est établi que les symptômes caractéristiques de l’intolérance au lactose sont associés à une carence en lactase dans le gros intestine. Ainsi, fournir au corps humain de la lactase est l’application ciblée par ce travail, par la conception de matériaux siliciques comme support d’encapsulation. En général, les types de cargos développés doivent surmonter les conditions gastriques pour libérer l’enzyme dans le gros intestine. La silice poreuse amorphe est un matériau inorganique non-toxique qui assure une bonne protection dans des conditions acides et permet une libération contrôlée au pH légèrement basique du colon. L’utilisation de silice amorphe poreuse permet à coût réduit d’obtenir une structure intrinsèque contrôlée (forme, taille particulaire, diamètre du pore) et une chimie de surface modifiable. En accord avec les objectifs principaux, quatre stratégies d’encapsulation bio-adaptées ont été étudiées comme de potentiels voies pour la production de compléments alimentaires solides d’intérêt pour le traitement de l’intolérance au lactose : (i) immobilisation de l’enzyme par adsorption dans des matériaux siliciques meso-macroporeux pré-synthétises, (ii) immobilisation de l’enzyme sur des particules de silice faiblement poreuses recouvertes par des liposomes, (iii) encapsulation de l’enzyme dans des nanoparticules de lipides solides (SLNs), (iv) encapsulation de l’enzyme dans une matrice de biopolymère recouvert d’une coque de silice mésoporeuse
The engineering of solid dietary supplements provides several advantages in the industrial formulation of food products, in terms of its production, storage and handling. Thereby, the goal of this doctoral work is to design bio-responsive carriers for the encapsulation of an exogenous enzyme able to catalyze the hydrolysis of lactose towards simple sugar molecules. In fact, there is a consensus that the onset of symptoms characteristic of lactose intolerance are associated with lactase deficiency in the small intestine. Providing the organism with exogenous lactase is the underlying application targeted by this work through the design of silicabased materials for encapsulation. The different types of bio-carriers developed had to overcome the simulated gastric conditions in order to release active enzyme molecules in the small intestine. Amorphous porous silica is a very good and non-toxic component affording protection versus acidic conditions, while providing controlled release. This inorganic material approved by the US Food and Drug Administration (FDA) has a relatively low cost, and presents a controlled structure (shape, size, pore diameter), as well as tunable surface chemistry. In agreement with the main objectives, four bio-adapted encapsulation strategies were investigated as potential routes to produce solid dietary supplements for lactose intolerance treatment: (i) physical entrapment of the enzyme in pre-synthesized meso-macroporous silica materials, (ii) physical entrapment of the enzyme in low porosity silica particles coated by liposomes, (iii) encapsulation of the enzyme into thermosensitive solid lipid nanoparticles (SLNs) (iv) encapsulation of the enzyme into a biopolymer matrix coated in a mesoporous silica shell
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Belhacene, Kalim. "Conception de BioMEMS assistée par plasma froid : nouvelles approches." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10034/document.

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La micro et la nanotechnologie a créé un bouleversement dans beaucoup de domaine tel que l’industrie ou la recherche. Pour la recherche, les enjeux économiques (quantité) et écologiques (déchets, risques chimiques) vont directement dans le sens de cette miniaturisation pour l’obtention de procédé sûr, propre et moins couteux. Cette thèse présente la mise en place d’un nouveau procédé de conception de BioMEMS assistée par plasma froid. L’objectif est le développement d’un microdispositif à partir d’un matériau non toxique, le Tetramethyldisiloxane (TMDSO), grâce à une technologie de dépôt de couche mince assisté par plasma, et intégrant une enzyme, pour la réalisation de réaction catalytique. Pour cela, un protocole d’immobilisation et d’intégration de l’enzyme, la β-galactosidase, a été développé afin de vérifier la capacité du TMDSO à retenir les enzymes et conserver sa fonction biologique. Ensuite, une évaluation de l’activité catalytique de l’enzyme immobilisée a été entreprise par la réalisation de réaction à l’échelle millifluidique, validant l’immobilisation ainsi que la biocompatibilité du ppTMDSO. Ensuite, un microréacteur à enzyme immobilisée a été réalisé, afin d’évaluer l’influence du passage à l’échelle microfluidique et de comprendre les phénomènes liés à la diffusion et la réaction des espèces au sein du dispositif. Enfin, la conception d’un microcanal en ppTMDSO et intégrant l’enzyme, a été réalisée afin de d’étudier la faisabilité d’une méthodologie « bio-integrante » pour la création d’un BioMEMS. L’utilisation d’une méthodologie bio-integrante peut être considérée comme une alternative prometteuse pour le développement de nouveaux outils de recherches
The micro and nanotechnology has created an upheaval in many field such as industry or research. For research, economic issues (quantity) and ecological (waste, chemical hazards) go straight in the direction of this miniaturization process for obtaining safe, clean and less expensive. This thesis presents the development of a new BioMEMS design process assisted by cold plasma. The objective is to develop a micro-device from a non-toxic material, tetramethyldisiloxane (TMDSO), through a plasma enhanced thin film deposition technology, and incorporating an enzyme, for carrying out catalytic reaction. For this, an immobilizer protocol and integration of the enzyme, β-galactosidase, was developed to verify TMDSO's ability to retain enzymes and retain its biological function. Then, an evaluation of the catalytic activity of the immobilized enzyme was carried out by carrying out the reaction millifluidic scale, validating the asset and the biocompatibility of ppTMDSO. Then, an immobilized enzyme microreactor was conducted to assess the influence of the transition to the microfluidic scale and understand the phenomena related to the diffusion and reaction of the species within the device. Finally, the design of a microchannel ppTMDSO and incorporating the enzyme, was conducted to study the feasibility of a "bio-integral 'methodology for establishing a BioMEMS. The use of a bio-integral method may be regarded as a promising alternative for the development of new research tools
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Rafael, Ruan Da Silva. "Imobilização de β-galactosidase através de ligações covalentes multipontuais em suporte contendo grupamentos epoxi." reponame:Repositório Institucional da UNIVATES, 2014. http://hdl.handle.net/10737/604.

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A enzima β – galactosidase é reconhecida por catalisar a hidrólise da lactose e possibilitar a formação de galactooligossacarídeos. O objetivo do presente trabalho foi estudar diferentes condições de imobilização de β – galactosidases de Aspergillus oryzae e Kluyveromyces lactis utilizando suporte comercial Immobead. Ambas as enzimas foram imobilizadas nos suportes tratados e não tratados com etilenodiamina e submetidas a processos de imobilização uni e multipontual. Os derivados também foram avaliados quanto ao bloqueio dos grupamentos epóxi com glicina. As análises de estabilidade ao armazenamento sob refrigeração, estabilidade térmica, ciclos de reuso para hidrólise da lactose, determinação das propriedades cinéticas e determinação de pH e temperatura ótimos foram realizadas nos derivados obtidos. Os resultados de eficiência de imobilização variaram de 30 a 50% e os valores de rendimento variaram entre 80 e 90%. Modificações químicas no suporte foram realizadas utilizando etilenodiamina com o objetivo de gerar modificações químicas no suporte, causando a rápida adsorção de enzimas e favorecendo a formação de ligações covalentes multipontuais em tempo reduzido. Verificou-se que suportes modificados com etilenodiamina imobilizaram a mesma carga de enzimas em menor tempo, quando comparados a suportes sem modificação. Entretanto, a significativa perda de atividade verificada nesses suportes durante os ciclos de reuso sugere que a superfície do suporte possa ter sido modificada em sua totalidade, dificultando a formação de ligações covalentes e permitindo a lixiviação de enzimas para o meio reacional. Derivados não bloqueados apresentaram perda considerável de atividade enzimática durante a armazenagem, indicando a ocorrência de possíveis distorções da enzima, ocasionadas pela interação de grupamentos epóxi livres. Ensaios submetidos à imobilização multipontual apresentaram melhorias em sua estabilidade térmica. Os valores de Km para as enzimas imobilizadas de K. lactis e A. oryzae foram 49,69 e 55,29 mM, valores superiores àqueles verificados para as enzimas livres (19,11 e 17,37 mM, respectivamente), indicando possíveis alterações conformacionais na estrutura da proteína, resultantes do processo de imobilização. Os resultados indicaram que derivados não tratados com etilenodiamina, submetidos à imobilização covalente multipontual e bloqueio com glicina apresentaram os resultados mais expressivos para as condições estudadas de estabilidade ao armazenamento, estabilidade térmica e ciclos de reuso para hidrólise de lactose. Esses derivados não apresentaram distorções em relação às condições ótimas de temperatura e pH quando comparadas com as respectivas enzimas livres. As β – galactosidases de A. oryzae e K. lactis submetidas à imobilização covalente multipontual no suporte Immobead posteriormente bloqueado com glicina apresentaram as melhores propriedades para futura aplicação industrial.
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7

Martins, André Rosa. "Conversão de lactose e síntese de galactoologossacarídeos por acão de β-galactosidade e de microrganismos probióticos em bioprocessos simultâneos com catálise e fermentação láctica." reponame:Repositório Institucional da FURG, 2009. http://repositorio.furg.br/handle/1/2434.

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Dissertação(mestrado)-Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia e Ciência de Alimentos, Escola de Química e Alimentos, 2009.
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Esse projeto desenvolveu um processo simultâneo de catálise e fermentação láctica visando obter um iogurte com características nutracêuticas. O objetivo principal foi avaliar a conversão da lactose e a síntese de galactooligossacarídeos (GOS) para um substrato específico, comparando biocatálises conduzidas simultaneamente à fermentação com os processos sem adição de enzima. A fermentação foi realizada a partir de cultura láctica liofilizada comercial contendo dois microrganismos probióticos, Bifidobacterium animalis e Lactobacillus acidophilus, associados aos microrganismos característicos do iogurte, Lactobacillus delbruekii subs. bulgaricus e Streptococcus salivarius subs. thermophilus. Foi utilizado um preparado enzimático contendo β- galactosidases obtidas de duas origens distintas: Kluyveromyces lactis e Aspergillus niger. Foram avaliados os efeitos das variações da concentração de lactose no substrato, da concentração de enzima e do tempo de adição da enzima em um planejamento experimental 23. As respostas foram o tempo de processo, a lactose final, a conversão da lactose, a densidade, a viscosidade, a sinérese e a concentração de GOS, comparando os processos enzimáticos e fermentativos simultâneos com a fermentação sem a adição de enzima. Os resultados indicaram um percentual de conversão da lactose entre 97,7 e 99,7% e uma produção de GOS nas condições de maior concentração inicial de lactose no substrato, menor concentração de enzima e maior tempo de defasagem na adição da enzima. Os efeitos sobre os parâmetros de textura foram negativos, indicando a necessidade de um acréscimo de agentes espessantes e estabilizantes nos bioprocessos simultâneos, quando do aumento da concentração de enzima. Observou-se, ainda, um impacto positivo no tempo de processamento quando da comparação entre os bioprocessos simultâneos e os processos de múltiplos estágios, na elaboração de fermentados lácticos com baixa concentração de lactose.
This project developed a simultaneous process of catalysis and lactic fermentation aiming to obtain a yogurt with nutraceuticals characteristics. The main objective was the conversion of lactose and the synthesis of galactooligosaccharides (GOS) for a specific substrate, comparing the biocatalysis conducted simultaneously to the fermentation with the processes without adding enzymes. Fermentation started with a commercial lactic lyophilized containing two probiotics microorganisms, Bifidobacterium animalis and Lactobacillus acidophilus, associated with microorganisms characteristics of yogurts, Lactobacillus delbruekii subs. bulgaricus and Streptococcus salivarius substhermophilus. It was used an enzymatic preparation containing β-galactosidases obtained from two distinct sources: Kluyveromyces lactis and Aspergillus niger. It were evaluated the effects of the variation of lactose concentration on the substrate, the enzyme concentration and the time of enzyme addition in an experimental design 23. The results were the process time, final lactose, lactose conversion, density, viscosity, sineresys and GOS concentration, comparing simultaneous enzymatic and fermentation processes with fermentation without the addition of enzymes. Results indicated a lactose conversion percentage between 97,7% and 99,7%, and a production of GOS in the condition of higher initial concentration of lactose in the substrate, lower enzyme concentration and more time of delayed in the addition of enzyme. The effects on texture parameters were negative, indicating the need for an increase of thickening agents and stabilizers in simultaneous bioprocesses when the increasing the enzyme concentration. It was also observed a positive impact on processing time when it was compared the simultaneous bioprocesses with the multiple stages processes in the elaboration of lactic fermented with low concentration of lactose.
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8

Klein, Manuela Poletto. "Imobilização de β-galactosidase para obtenção de produtos lácteos com baixo teor de lactose." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/24803.

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A β-galactosidase (E.C 3.2.1.23) é uma das enzimas mais empregadas na indústria de alimentos sendo utilizada na hidrólise da lactose. Neste trabalho foram utilizadas duas metodologias para imobilização desta enzima. Na primeira delas foi empregado como suporte um material híbrido à base de sílica que possui um grupo orgânico catiônico covalentemente ligado. A adsorção da enzima a este material apresentou eficiência que variou de 74 a 53% com o aumento da quantidade de enzima aplicada ao suporte. A baixa estabilidade térmica da enzima imobilizada obtida e as prováveis fracas interações envolvidas na sua adsorção a este suporte podem explicar o decréscimo de atividade observada durante as sucessivas bateladas de hidrólise da lactose. Na primeira batelada o grau de hidrólise foi de 90,9% e no final da última batelada (4ª), a enzima foi capaz de converter apenas 13% do substrato. A segunda metodologia utilizada foi imobilização covalente da enzima em um filme de celulose/líquido iônico modificado com uma poliamina e ativado com glutaraldeído. A presença da poliamina foi confirmada por análises de infravermelho. Após a imobilização, a enzima reteve 60% de sua atividade inicial. Bons resultados de hidrólise da lactose em batelada foram obtidos tanto a 7ºC como a 35ºC e foi possível reutilizar a enzima imobilizada por 16 ciclos consecutivos, a 7ºC, sem mudanças significativas na atividade enzimática. O valor de Km para a enzima imobilizada no material híbrido à base de sílica foi de 9,17 mM e para a enzima imobilizada nos filmes de celulose foi de 11,22 mM, ambos apresentaram um acréscimo quando comparados ao Km enzima livre (1,25 mM), devido à dificuldade de acesso do substrato ao sítio ativo da enzima. Não houve mudança no pH e temperatura ótimos da enzima imobilizada em relação à enzima livre em nenhum dos métodos testados.
β-galactosidase (E.C 3.2.1.23) is the most widely used enzymes in the food industry and its employed in the lactose hydrolysis process. In this study, two methodologies were used to test their immobilization. In the first, the enzyme was immobilized by adsorption in one silica based hybrid material that contains a cationic organic group covalently linked. The efficiency of immobilization showed a decrease of 74 to 53% by increasing the protein load applied to the support. The low thermo stability of the immobilized enzyme and the probable weak interactions involved in their adsorption, could explain the decrease in enzyme activity observed in the successive batch hydrolysis of lactose. In the first run, the degree of lactose hydrolysis was 90.9% and, at the end of the last run (4th), the enzyme was able to convert only 13% of the substrate. The second methodology used was the covalent immobilization of the enzyme on a cellulose/ionic liquid film, modified with a polyamine and activated using glutaraldehyde. The presence of a polyamine was confirmed by infrared analysis. After immobilization, the enzyme retained 60% of its initial activity. Highly efficient lactose conversion was achieved in a batch process at 7ºC and 35ºC and was possible to reuse the immobilized enzyme in 16 repeated cycles, at 7ºC, without any drastic decrease in enzyme activity. Km value for the immobilized enzyme in silica based hybrid material was 9.17 mM and for the enzyme immobilized in the film of cellulose/ionic liquid was 11.22 mM, both showing an increase compared with the Km value for free enzyme (1.25 mM), due to the difficulty of access of the substrate to the active sites of the enzyme. The immobilized enzyme did not show any changes in the optimal pH and temperature when compared to the free enzyme in both methods tested.
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Bezerra, Camilla Salviano. "Imobilização de β-galactosidase de Kluyveromyces lactis em diferentes suportes e protocolos de ativação." reponame:Repositório Institucional da UFC, 2012. http://www.repositorio.ufc.br/handle/riufc/10788.

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BEZERRA, C. S. Imobilização de β-galactosidase de Kluyveromyces lactis em diferentes suportes e protocolos de ativação. 2012. 115 f. Dissertação (Mestrado em Engenharia Química) - Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2012.
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β-galactosidase immobilization was studied seeking to add value to cheese whey trough lactose hydrolyze producing galactose and glucose. This work aimed to develop biocatalysts using different organic supports and activation protocols. Firstly, some supports were prepared as chitosan 2.5% (w/v) (with and without pretreatment with dimethylformamide) and 2.0% (w/v), chitosan-alginate-epoxide (QAE), cashew bagasse (BC) and coconut shell fiber (CV), which were activated in different ways with glutaraldehyde, epichlorohydrin or glycidol. Initially, it was determined the immobilization yield, couple yield and apparent activity from obtained catalysts, being chosen six derivatives according to better results parameters: 2.5% chitosan (w/v) glutaraldehyde activated (QUITGLU1), 2.0% chitosan (w/v) KOH coagulated at 50°C glutaraldehyde activated (QUITGLU2) and epichlorohydrin (QUITEPI) or glycidol (QUITGLI), chitosan 2.5% (w/v) dimethylformamide treated with epichlorohydrin (QUIT-DMFEPI) or glycidol (QUIT-DMFGLI). Thus, catalysts (QUITGLU1, QUITGLU2, QUITEPI, QUITGLI) were studied as operational stability by using a continuous reactor, as well as, maximum enzyme loading and effectiveness assays. Then, it was determined QUITGLU2 as the best biocatalyst and following studies were carried out: immobilization time, enzyme optimum temperature and pH, kinetic parameters using lactose as substrate at 37°C, storage at 10°C and operational stability using high load enzyme and cheese whey as substrate. CV and BC supports did not present good results for β-Kluyveromyces lactis galactosidase immobilization, as well as, QAE support. Supports treated with dimethylformamide presented low immobilization yields. The results for QUITGLU2 derivative presented maximum loading of 75 mgProtein.g-1support and higher effectiveness than others. The operational stability for this derivative remained stable, with constant glucose production for 10 h of reaction. Immobilization time of 3h proved enough for the process. The Km and Vmáx values were respectively: free enzyme (46.79 mM and 7,142.86 μmol.(mL.min)-1) and catalyst (69.56 mM and 113.25 μmol.(g.min)-1). During 120 days of storage at 10°C, no decrease derivative hydrolitic activity was noted, demonstrating satisfactory storage stability. Finally, the biocatalyst showed good results as operational stability when used high offered enzyme load (theoretically immobilized load 255.9 mgProtein.g-1chitosan) for cheese whey hydrolysis
A imobilização de β-galactosidase para hidrólise de lactose é uma proposta para agregar valor ao soro de leite com conseqüente produção de galactose e glicose. O objetivo deste trabalho foi desenvolver biocatalisadores a partir de diferentes suportes orgânicos e protocolos de ativação visando à hidrólise de lactose proveniente do soro de leite. Inicialmente, prepararam-se os suportes a serem aplicados no estudo como quitosana 2,5% (m/v) (sem e com pré-tratamento com dimetilformamida) e 2,0% (m/v), quitosana-alginato-epoxilado (QAE), bagaço de caju (BC) e fibra de casca de coco verde (CV), os quais foram ativados de diferentes formas, com glutaraldeído, epicloridrina ou glicidol. Na primeira etapa, determinaram-se o rendimento de imobilização, atividade recuperada e atividade aparente dos diferentes derivados obtidos para assim determinar os seis melhores – quitosana 2,5% (m/v) ativada com glutaraldeído (QUITGLU1), quitosana 2,0% (m/v) coagulada com KOH a 50°C ativada com glutaraldeído (QUITGLU2) ou epicloridrina (QUITEPI) ou glicidol (QUITGLI), quitosana 2,5% (m/v) tratada com dimetilformamida ativada com epicloridrina (QUIT-DMFEPI) ou glicidol (QUIT-DMFGLI). Para segunda fase, os catalisadores (QUITGLU1, QUITGLU2, QUITEPI, QUITGLI) foram estudados quanto à estabilidade operacional com o uso de reator contínuo, assim como ensaios de carga máxima e efetividade. Baseado nestes ensaios determinou-se QUITGLU2 como melhor biocatalisador e realizaram-se os seguintes estudos: variação do tempo de imobilização, determinação da melhor temperatura e pH para atividade enzimática, determinação de parâmetros cinéticos, estocagem sob 10°C e estabilidade operacional com o uso de alta carga enzimática usando soro de leite como substrato. Suportes como CV e BC não apresentaram boa adequação para imobilização de β-galactosidase de Kluyveromyces lactis, assim como o suporte QAE. Suportes com tratamento com dimetilformamida apresentaram baixos rendimentos de imobilização. Os resultados para o derivado QUITGLU2 apresentaram carga máxima de 75 mgProteína.g-1 de suporte e efetividade superiores aos demais. A estabilidade operacional para este derivado apresentou-se estável, visto sua produção de glicose constante por 10 h de reação. O tempo 3 h mostrou-se suficiente para imobilização. Os valores de Km e Vmáx tanto para enzima solúvel (46,79 mM e 7.142,86 μmol.(mL.min)-1) quanto para o derivado (69,56 mM e 113,25 μmol.(g.min)-1). Durante os 120 dias de armazenamento sob 10°C, não houve decréscimo da atividade hidrolítica do derivado, demonstrando ótima estabilidade à estocagem. Por fim, o biocatalisador mostrou bons resultados de estabilidade operacional quando utilizado em alta carga oferecida (255,9 mgProteína.g-1 de quitosana de carga teoricamente imobilizada) para hidrólise de soro de leite
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Lima, Micael de Andrade. "Recuperação e purificação de β-galactosidase de Kluyveromyces lactis utilizando cromatografia de modo misto." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/10781.

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LIMA, M. A. Recuperação e purificação de β-galactosidase de Kluyveromyces lactis utilizando cromatografia de modo misto. 2014. 98 f. Dissertação (Mestrado em Engenharia Química) - Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2014.
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The most important lactases, as far as biotechnological interest is concerned, are those produced by Kluyveromyces yeasts, which are intracellular and currently obtained mostly by submerged-state fermentation. This technique, just as the mainstream biotechnological processes, involves a need for protein and peptide purification from a variety of sources. In this context, one of the most promising notable techniques that can be highlighted is Mixed Mode Chromatography, which allows simultaneous ionic and hydrophobic interactions between the adsorbent and the adsorbate. Thus, the aim of this work was to assess the feasibility of recovery and purification of a Kluyveromyces lactis β-galactosidase, produced via fermentation process, by employing Mixed Mode Chromatography. Unit operations, such as protein precipitation and dialysis were also performed in order to concentrate the enzyme of interest and eliminate cell debris and other interferences inherent in the fermentation medium, something that would result in a decrease in the process yield. The production showed satisfactory results, with mean values for total enzyme concentration of 0.45 mg/mL, enzymatic activity of 77 U/mL and specific activity of 167,9 U/mg. The Purification Factor obtained was 1.17. A precipitation step, followed by a dialysis process, was performed and the later chromatographic run carried out in fixed bed with this material yielded recovery values of 41.0 and 48.2% of total protein and activity, respectively. SDS-PAGE Electrophoresis confirmed the purification evolution throughout the unit operations employed, confirming the viability of the employment of the techniques used to obtain an enzyme of considerable degree of purity and possessing high-added value.
As mais importantes lactases, em termos de interesse biotecnológico, são aquelas produzidas por leveduras do gênero Kluyveromyces, que são intracelulares e, em sua maioria, são obtidas por fermentação em cultura submersa. Esta técnica, assim como a maioria dos processos biotecnológicos, envolve a necessidade de purificação de proteínas e peptídeos a partir de uma variedade de fontes. Neste contexto, uma das técnicas mais notavelmente promissoras é a cromatografia de modo misto, que permite interações iônicas e hidrofóbicas simultaneamente entre o adsorvente e o adsorbato. O objetivo do presente trabalho foi estudar a viabilidade da recuperação e purificação da enzima β-galactosidase, produzida por meio de processo fermentativo e utilizando o micro-organismo Kluyveromyces lactis, por técnica de cromatografia de modo misto. Operações unitárias de precipitação proteica e diálise foram também realizadas com o intuito de concentrar a enzima de interesse e eliminar detritos celulares e outros interferentes advindos do meio de fermentação, o que ocasionaria uma diminuição do rendimento do processo. A produção se apresentou satisfatória, com uma média de valores de concentração de enzimas totais de 0,45 mg/mL, atividade enzimática de 67 U/mL, atividade específica de 167,9 U/mg. O Fator de Purificação obtido foi de 1,17. Uma precipitação seguida de diálise foi realizada e a posterior corrida cromatográfica em leito fixo com esse material rendeu valores de recuperação de 41,0 e 48,2% de proteína total e atividade total, respectivamente. A análise de eletroforese SDS-PAGE confirmou a evolução do processo de purificação no decorrer das operações unitárias, atestando a viabilidade do emprego das técnicas utilizadas para obtenção de enzimas com considerável grau de pureza com alto valor comercial agregado.
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Books on the topic "Β-galactosidases"

1

Gonawan, Fadzil Noor. Immobilized β-Galactosidase-Mediated Conversion of Lactose: Process, Kinetics and Modeling Studies. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-3468-9.

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Gonawan, Fadzil Noor. Immobilized β-Galactosidase-Mediated Conversion of Lactose: Process, Kinetics and Modeling Studies. Springer, 2019.

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Book chapters on the topic "Β-galactosidases"

1

Harju, M. "Hydrolysis of Lactulose and Lactitol with β-Galactosidases." In MILK the vital force, 232. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-3733-8_191.

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Plou, Francisco J., Julio Polaina, Julia Sanz-Aparicio, and María Fernández-Lobato. "β-Galactosidases for Lactose Hydrolysis and Galactooligosaccharide Synthesis." In Microbial Enzyme Technology in Food Applications, 121–44. Boca Raton, FL : CRC Press, [2016] | Series: Food biology series | “A science publishers book.”: CRC Press, 2017. http://dx.doi.org/10.1201/9781315368405-9.

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Cieśliński, Hubert, Marta Wanarska, Anna Pawlak-Szukalska, Ewelina Krajewska, Monika Wicka, and Józef Kur. "Cold-Active β-Galactosidases: Sources, Biochemical Properties and Their Biotechnological Potential." In Biotechnology of Extremophiles:, 445–69. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-13521-2_15.

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Isobe, Kimiyasu, and Miwa Yamada. "β-Galactosidases from an Acidophilic Fungus, Teratosphaeria acidotherma AIU BGA-1." In Fungi in Extreme Environments: Ecological Role and Biotechnological Significance, 419–40. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-19030-9_21.

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Rubens, P., P. Degraeve, P. Lemay, and K. Heremans. "Pressure and Temperature Stability of β-Galactosidases: A Structural and Functional Study." In Advances in High Pressure Bioscience and Biotechnology, 227–30. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-60196-5_50.

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Zabin, Irving. "From Acetylase to β-Galactosidase." In Origins of Molecular Biology, 189–98. Washington, DC, USA: ASM Press, 2014. http://dx.doi.org/10.1128/9781555817763.ch20.

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Wisdom, G. Brian. "β-Galactosidase Labeling of IgG Antibody." In Springer Protocols Handbooks, 677–79. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-59745-198-7_65.

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Monroe, Dan. "A Novel Homogeneous β-Galactosidase Immunoassay System." In Reviews on Immunoassay Technology, 70–76. London: Palgrave Macmillan UK, 1989. http://dx.doi.org/10.1007/978-1-349-11009-4_5.

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Wisdom, G. Brian. "β-Galactosidase Labeling of Antibody Using MBS." In Springer Protocols Handbooks, 271–72. Totowa, NJ: Humana Press, 1996. http://dx.doi.org/10.1007/978-1-60327-259-9_42.

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Itahana, Koji, Yoko Itahana, and Goberdhan P. Dimri. "Colorimetric Detection of Senescence-Associated β Galactosidase." In Methods in Molecular Biology, 143–56. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-239-1_8.

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Conference papers on the topic "Β-galactosidases"

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Zolnere, Kristine, and Inga Ciprovica. "The comparison of commercially available β-galactosidases for dairy industry : review." In Research for Rural Development, 2017. Latvia University of Agriculture, 2017. http://dx.doi.org/10.22616/rrd.23.2017.032.

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Tian, Jing, Ping Zhao, Longquan Xu, Xu Fei, and Yi Wang. "Purification of soyasaponin -β-galactosidase fromAspergillussp.39." In Third International Conference on Photonics and Image in Agriculture Engineering (PIAGENG 2013), edited by Honghua Tan. SPIE, 2013. http://dx.doi.org/10.1117/12.2019642.

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Gennari, Adriano, Francielle Herrmann Mobayed, Giandra Volpato, and Claucia Fernanda Volken de Souza. "Caracterização da β-Galactosidase Imobilizada em Immobead 150." In Simpósio de Bioquímica e Biotecnologia. Londrina - PR, Brazil: Galoa, 2017. http://dx.doi.org/10.17648/simbbtec-2017-80818.

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Braga, Anna Rafaela Cavalcante, and Veridiana Vera de Rosso. "ATIVIDADE DAS ENZIMAS β-GALACTOSIDASE, β-GLUCOSIDASE E α-GALACTOSIDASE DURANTE A FERMENTAÇÃO DA POLPA DE JUÇARA (Euterpe edulis Mart.)." In Simpósio Nacional de Bioprocessos e Simpósio de Hidrólise Enzimática de Biomassa. Campinas - SP, Brazil: Galoá, 2015. http://dx.doi.org/10.17648/sinaferm-2015-31918.

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Athayde, C. M., and M. C. Scrutton. "ROLE OF GUANINE NUCLEOTIDES IN Ca2+ - DEPENDENT LYSOSOMAL SECRETION FROM ELECTROPERMEABILISED PLATELETS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644513.

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Abstract:
Previous studies have shown that the maximal extent of Ca2+ dependent secretion of β-N-acetylglucosaminidase (B-N-AcGlc) from electropermeabilised human platelets can be enhanced by addition of thrombin or of 1-oleyl-2-acetylglycerol or 12-0-tetradecanoyl phorbol-13-acetate without a significant alteration in the EC^q for Ca2+. (Knight et al. Europ. J. Biochem.,143337 (1984)). We have found a similar Ca2+ dependent increase in the maximal extent of β-N-AcGlc and β-galactosidase secretion on addition of metabolically stable analogues of GTP (GTPγS and GppNHp) in the absence of thrombin or of GTP added in the presence of a nonsaturating concentration of thrombin. The EC50 values for GTP and GppNHp do not differ significantly for β-N-AcGlc and 3H-5HT secretion, but GTPγS is significantly more effective for 3H-5HT secretion.The time course of β-N-AcGlc secretion induced by GTPγS shows a significant delay as compared with that induced by thrombin + Ca2+. No significant differences could be detected between the properties of β-N-AcGlc or β-galactosidase secretion in this system. The results are consistent with involvement of a GTP binding protein (Np) in receptor-phospholipase C coupling mediating lysosomal secretion, but provide no indication that an additional protein of this type (Ne) is involved as has been proposed for lysosomal secretion from neutrophils. We have thus far failed to find evidence for heterogeneity in lysosomal secretion in this system (supported by SERC and Ciba-Geigy).
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Zolnere, Kristine, Janis Liepins, and Inga Ciprovica. "The impact of calcium ions on commercially available β-galactosidase." In Baltic Conference on Food Science and Technology FOODBALT “Food for consumer well-being”. Latvia University of Agriculture. Faculty of Food Technology., 2017. http://dx.doi.org/10.22616/foodbalt.2017.017.

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Breger, Joyce C., Anthony P. Malanoski, Carl W. Brown, Jeffrey R. Deschamps, Kimhiro Susumu, Eunkeu Oh, George P. Anderson, Scott A. Walper, and Igor L. Medintz. "Probing kinetic enhancement of β-galactosidase-nanoparticle complexes (Conference Presentation)." In Colloidal Nanoparticles for Biomedical Applications XIII, edited by Xing-Jie Liang, Wolfgang J. Parak, and Marek Osiński. SPIE, 2018. http://dx.doi.org/10.1117/12.2289988.

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Jiang, Jian-Xing, and Yu-kaung Chang. "Process Design for Production of β-Galactosidase from Pichia Pastoris." In 14th Asia Pacific Confederation of Chemical Engineering Congress. Singapore: Research Publishing Services, 2012. http://dx.doi.org/10.3850/978-981-07-1445-1_707.

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Yuki Grafulin, Vanessa, Bruna Coelho Andrade, Rafaela Rubim, Claucia Fernanda Volken de Souza, Jocelei Maria Chies, Diógenes Santiago Santos, Gaby Renard, and Giandra Volpato. "CLONAGEM DO GENE QUE CODIFICA A β-GALACTOSIDASE DE Kluyveromyces sp." In Simpósio Nacional de Bioprocessos e Simpósio de Hidrólise Enzimática de Biomassa. Campinas - SP, Brazil: Galoá, 2015. http://dx.doi.org/10.17648/sinaferm-2015-33641.

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SILVA, E. C. da, P. D. SANTOS, G. A. A. FERNANDES, A. M. O. MOTA, A. L. F. PORTO, and M. T. H. CAVALCANTI. "PRODUÇÃO DE β-GALACTOSIDASE POR BACTÉRIAS ÁCIDO LÁTICAS UTILIZANDO SORO DE LEITE." In XX Congresso Brasileiro de Engenharia Química. São Paulo: Editora Edgard Blücher, 2015. http://dx.doi.org/10.5151/chemeng-cobeq2014-0533-25073-142946.

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Reports on the topic "Β-galactosidases"

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Olson, Joan. Repression of β-galactosidase synthesis in Escherichia coli by salicylates. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.1125.

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