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Chen T, Wang S, Niu H, Yang G, Wang S, Wang Y, Zhou C, Yu B, Yang P, Sun W, Liu D, Ying H, Chen Y. Biofilm-Based Biocatalysis for Galactooligosaccharides Production by the Surface Display of β-Galactosidase in Pichia pastoris. Int J Mol Sci 2023; 24:ijms24076507. [PMID: 37047479 PMCID: PMC10094928 DOI: 10.3390/ijms24076507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023] Open
Abstract
Galactooligosaccharides (GOS) are one of the most important functional oligosaccharide prebiotics. The surface display of enzymes was considered one of the most excellent strategies to obtain these products. However, a rough industrial environment would affect the biocatalytic process. The catalytic process could be efficiently improved using biofilm-based fermentation with high resistance and activity. Therefore, the combination of the surface display of β-galactosidase and biofilm formation in Pichia pastoris was constructed. The results showed that the catalytic conversion rate of GOS was up to 50.3% with the maximum enzyme activity of 5125 U/g by screening the anchorin, and the number of the continuous catalysis batches was up to 23 times. Thus, surface display based on biofilm-immobilized fermentation integrated catalysis and growth was a co-culture system, such that a dynamic equilibrium in the consolidated integrative process was achieved. This study provides the basis for developing biofilm-based surface display methods in P. pastoris during biochemical production processes.
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Enhanced thermal stability of the β-galactosidase BgaB from Bacillus circulans by cyclization mediated via SpyTag/SpyCatcher interaction and its use in galacto-oligosaccharides synthesis. Int J Biol Macromol 2022; 222:2341-2352. [DOI: 10.1016/j.ijbiomac.2022.10.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/22/2022] [Accepted: 10/04/2022] [Indexed: 11/05/2022]
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3
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A novel salt-tolerant GH42 β-galactosidase with transglycosylation activity from deep-sea metagenome. World J Microbiol Biotechnol 2022; 38:154. [PMID: 35796808 DOI: 10.1007/s11274-022-03348-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/24/2022] [Indexed: 10/17/2022]
Abstract
β-Galactosidase is a widely adopted enzyme in the food and pharmaceutical industries. Metagenome techniques have the advantage of discovering novel functional genes, particularly potential genes from uncultivated microbes. In this study, a novel GH42 β-galactosidase isolated from a deep-sea metagenome was overexpressed in Escherichia coli BL21 (DE3) and purified by affinity chromatography. The optimal temperatures and pH of the enzyme for o-nitrophenyl-β-D-galactopyranoside (oNPG) and lactose were 40 ℃, 6.5 and 50 ℃, 7, respectively. The enzyme was stable at temperatures between 4 and 30 ℃ and within the pH range of 6-9. Moreover, it was highly tolerant to salt and inhibited by Zn2+ and Cu2+. The kinetic values of Km and kcat of the enzyme against oNPG were 1.1 mM and 57.8 s-1, respectively. Furthermore, it showed hydrolysis and transglycosylation activity to lactose and the extra monosaccharides could improve the productivity of oligosaccharides. Overall, this recombinant β-galactosidase is a potential biocatalyst for the hydrolysis of milk lactose and synthesis of functional oligosaccharides.
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de Albuquerque TL, de Sousa M, Gomes E Silva NC, Girão Neto CAC, Gonçalves LRB, Fernandez-Lafuente R, Rocha MVP. β-Galactosidase from Kluyveromyces lactis: Characterization, production, immobilization and applications - A review. Int J Biol Macromol 2021; 191:881-898. [PMID: 34571129 DOI: 10.1016/j.ijbiomac.2021.09.133] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/30/2021] [Accepted: 09/20/2021] [Indexed: 01/06/2023]
Abstract
A review on the enzyme β-galactosidase from Kluyveromyces lactis is presented, from the perspective of its structure and mechanisms of action, the main catalyzed reactions, the key factors influencing its activity, and selectivity, as well as the main techniques used for improving the biocatalyst functionality. Particular attention was given to the discussion of hydrolysis, transglycosylation, and galactosylation reactions, which are commonly mediated by this enzyme. In addition, the products generated from these processes were highlighted. Finally, biocatalyst improvement techniques are also discussed, such as enzyme immobilization and protein engineering. On these topics, the most recent immobilization strategies are presented, emphasizing processes that not only allow the recovery of the biocatalyst but also deliver enzymes that show better resistance to high temperatures, chemicals, and inhibitors. In addition, genetic engineering techniques to improve the catalytic properties of the β-galactosidases were reported. This review gathers information to allow the development of biocatalysts based on the β-galactosidase enzyme from K. lactis, aiming to improve existing bioprocesses or develop new ones.
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Affiliation(s)
- Tiago Lima de Albuquerque
- Federal University of Ceará, Technology Center, Chemical Engineering Department, Campus do Pici, Bloco 709, 60 455 - 760 Fortaleza, Ceará, Brazil
| | - Marylane de Sousa
- Federal University of Ceará, Technology Center, Chemical Engineering Department, Campus do Pici, Bloco 709, 60 455 - 760 Fortaleza, Ceará, Brazil
| | - Natan Câmara Gomes E Silva
- Federal University of Ceará, Technology Center, Chemical Engineering Department, Campus do Pici, Bloco 709, 60 455 - 760 Fortaleza, Ceará, Brazil
| | - Carlos Alberto Chaves Girão Neto
- Federal University of Ceará, Technology Center, Chemical Engineering Department, Campus do Pici, Bloco 709, 60 455 - 760 Fortaleza, Ceará, Brazil
| | - Luciana Rocha Barros Gonçalves
- Federal University of Ceará, Technology Center, Chemical Engineering Department, Campus do Pici, Bloco 709, 60 455 - 760 Fortaleza, Ceará, Brazil
| | - Roberto Fernandez-Lafuente
- Instituto de Catálisis y Petroleoquímica - CSIC, Campus of excellence UAM-CSIC, Cantoblanco, 28049 Madrid, Spain; Center of Excellence in Bionanoscience Research, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Maria Valderez Ponte Rocha
- Federal University of Ceará, Technology Center, Chemical Engineering Department, Campus do Pici, Bloco 709, 60 455 - 760 Fortaleza, Ceará, Brazil.
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Li N, Liu Y, Wang C, Weng P, Wu Z, Zhu Y. Overexpression and characterization of a novel GH4 galactosidase with β-galactosidase activity from Bacillus velezensis SW5. J Dairy Sci 2021; 104:9465-9477. [PMID: 34127264 DOI: 10.3168/jds.2021-20258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022]
Abstract
A novel galactosidase gene (gal3149) was identified from Bacillus velezensis SW5 and heterologously expressed in Escherichia coli BL21 (DE3). The novel galactosidase, Gal3149, encoded by gal3149 in an open reading frame of 1,299 bp, was 433 amino acids in length. Protein sequence analysis showed that Gal3149 belonged to family 4 of glycoside hydrolases (GH4). Gal3149 displayed higher enzyme activity for the substrate 2-nitrophenyl-β-d-galactopyranoside (oNPG) than for 4-nitrophenyl-α-d-galactopyranoside (pNPαG). This is the first time that an enzyme belonging to GH4 has been shown to exhibit β-galactosidase activity. Gal3149 showed optimal activity at pH 8.0 and 50°C, and exhibited excellent thermal stability, with retention of 50% relative activity after incubation at a temperature range of 0 to 50°C for 48 h. Gal3149 activity was significantly improved by K+ and Na+, and was strongly or completely inhibited by Ag+, Zn2+, Tween-80, Cu2+, carboxymethyl cellulose, and oleic acid. The rate of hydrolyzed lactose in 1 mL of milk by 1 U of Gal3149 reached about 50% after incubation for 4 h. These properties lay a solid foundation for Gal3149 in application of the lactose-reduced dairy industry.
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Affiliation(s)
- Na Li
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, People's Republic of China
| | - Yang Liu
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, People's Republic of China; Institute of Quality Standards and Testing Technology for Agro-Products, Fujian Academy of Agricultural Sciences, Fuzhou 350003, People's Republic of China
| | - Changyu Wang
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, People's Republic of China
| | - Peifang Weng
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, People's Republic of China
| | - Zufang Wu
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, People's Republic of China.
| | - Yazhu Zhu
- Zhejiang International Maritime College, Zhoushan 316021, People's Republic of China
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A novel β-galactosidase from Klebsiella oxytoca ZJUH1705 for efficient production of galacto-oligosaccharides from lactose. Appl Microbiol Biotechnol 2020; 104:6161-6172. [DOI: 10.1007/s00253-020-10679-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/04/2020] [Accepted: 05/10/2020] [Indexed: 12/28/2022]
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Liu P, Xie J, Liu J, Ouyang J. A novel thermostable β-galactosidase from Bacillus coagulans with excellent hydrolysis ability for lactose in whey. J Dairy Sci 2019; 102:9740-9748. [DOI: 10.3168/jds.2019-16654] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 07/08/2019] [Indexed: 01/19/2023]
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Aburto C, Castillo C, Cornejo F, Arenas-Salinas M, Vásquez C, Guerrero C, Arenas F, Illanes A, Vera C. β-Galactosidase from Exiguobacterium acetylicum: Cloning, expression, purification and characterization. BIORESOURCE TECHNOLOGY 2019; 277:211-215. [PMID: 30639092 DOI: 10.1016/j.biortech.2019.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 12/31/2018] [Accepted: 01/02/2019] [Indexed: 06/09/2023]
Abstract
The main goal of this work was to evaluate the performance of β-galactosidase from Exiguobacterium acetylicum MF03 in both hydrolysis and transgalactosylation reactions from different substrates. The enzyme gene was expressed in Escherichia coli BL21 (DE3), sequenced, and subjected to bioinformatic and kinetic assessment. Results showed that the enzyme was able to hydrolyze lactulose and o-nitrophenyl-β-d-galactopyranoside, but unable to hydrolyze lactose, o-nitrophenyl-β-d-glucopyranoside, butyl- and pentyl-β-d-galactosides. This unique and novel substrate specificity converts the E. acetylicum MF03 β-galactosidase into an ideal catalyst for the formulation of an enzymatic kit for lactulose quantification in thermally processed milk. This is because costly steps to eliminate glucose (resulting from hydrolysis of lactose when a customary β-galactosidase is used) can be avoided.
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Affiliation(s)
- Carla Aburto
- School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso (PUCV), Valparaíso, Chile
| | - Carlos Castillo
- Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH), Santiago, Chile
| | - Fabián Cornejo
- Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH), Santiago, Chile
| | - Mauricio Arenas-Salinas
- Center of Bioinformatic and Molecular Simulation, Faculty of Engineering, Universidad de Talca (UTALCA), Talca, Chile
| | - Claudio Vásquez
- Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH), Santiago, Chile
| | - Cecilia Guerrero
- School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso (PUCV), Valparaíso, Chile
| | - Felipe Arenas
- Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH), Santiago, Chile
| | - Andrés Illanes
- School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso (PUCV), Valparaíso, Chile
| | - Carlos Vera
- Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH), Santiago, Chile.
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Zhao L, Zhou Y, Qin S, Qin P, Chu J, He B. β-Galactosidase BMG without galactose and glucose inhibition: Secretory expression in Bacillus subtilis and for synthesis of oligosaccharide. Int J Biol Macromol 2018; 120:274-278. [DOI: 10.1016/j.ijbiomac.2018.07.148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 07/22/2018] [Accepted: 07/23/2018] [Indexed: 10/28/2022]
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10
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Katrolia P, Liu X, Li G, Kopparapu NK. Enhanced Properties and Lactose Hydrolysis Efficiencies of Food-Grade β-Galactosidases Immobilized on Various Supports: a Comparative Approach. Appl Biochem Biotechnol 2018; 188:410-423. [DOI: 10.1007/s12010-018-2927-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/19/2018] [Indexed: 12/30/2022]
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Xavier JR, Ramana KV, Sharma RK. β-galactosidase: Biotechnological applications in food processing. J Food Biochem 2018. [DOI: 10.1111/jfbc.12564] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Janifer Raj Xavier
- Food Biotechnology Division, Defence Food Research Laboratory; Defence Research and Development Organization; Mysore Karnataka India
| | - Karna Venkata Ramana
- Food Biotechnology Division, Defence Food Research Laboratory; Defence Research and Development Organization; Mysore Karnataka India
| | - Rakesh Kumar Sharma
- Defence Food Research Laboratory; Defence Research and Development Organization; Mysore Karnataka India
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Xia Y, He L, Mao J, Fang P, Ma X, Wang Z. Purification, characterization, and gene cloning of a new cold-adapted β-galactosidase from Erwinia sp. E602 isolated in northeast China. J Dairy Sci 2018; 101:6946-6954. [DOI: 10.3168/jds.2018-14605] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 04/15/2018] [Indexed: 12/22/2022]
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13
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Biochemical characterization of a novel β-galactosidase from Paenibacillus barengoltzii suitable for lactose hydrolysis and galactooligosaccharides synthesis. Int J Biol Macromol 2017; 104:1055-1063. [PMID: 28652150 DOI: 10.1016/j.ijbiomac.2017.06.073] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 06/03/2017] [Accepted: 06/15/2017] [Indexed: 11/23/2022]
Abstract
A β-galactosidase gene (PbBGal2A) was cloned from Paenibacillus barengoltzii and expressed in Escherichia coli. The in silico analysis of the deduced amino acid sequences revealed that PbBGal2A shared the highest identity of 40% with the characterized glycoside hydrolase (GH) family 2 β-galactosidase from Actinobacillus pleuropneumoniae. The recombinant β-galactosidase (PbBGal2A) was purified with a molecular mass of 124.2kDa on SDS-PAGE. The optimal pH and temperature of PbBGal2A were determined to be pH 7.5 and 45°C, respectively. PbBGal2A was stable within pH 6.0-8.0 and up to 45°C. It completely hydrolyzed the lactose in milk and whey powder solution. In addition, PbBGal2A exhibited high transglycosylation activity and a maximum yield of 47.9% (w/w) for galactooligosaccharides (GOS) production was obtained in 8h at a lactose concentration of 350g/L. These properties make PbBGal2A an ideal candidate for commercial use in the production of lactose-free milk and GOS.
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Letsididi R, Hassanin HA, Koko MY, Ndayishimiye JB, Zhang T, Jiang B, Stressler T, Fischer L, Mu W. Characterization of a thermostable glycoside hydrolase (CMbg0408) from the hyperthermophilic archaeon Caldivirga maquilingensis IC-167. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:2132-2140. [PMID: 27582034 DOI: 10.1002/jsfa.8019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 08/17/2016] [Accepted: 08/27/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Hyperthermophilic archaea capable of functioning optimally at very high temperatures are a good source of unique and industrially important thermostable enzymes. RESULTS A glycoside hydrolase family 1 β-galactosidase gene (BglB) from a hyperthermophilic archaeon Caldivirga maquilingensis IC-167 was cloned and expressed in Escherichia coli. The recombinant enzyme (CMbg0408) displayed optimum activity at 110 °C and pH 5.0. It also retained 92% and 70% of its maximal activity at 115 and 120 °C, respectively. The enzyme was completely thermostable and active after 120 min of incubation at 80 and 90 °C. It also showed broad substrate specificity with activities of 8876 ± 185 U mg-1 for p-nitrophenyl-β-d-galactopyranoside, 4464 ± 172 U mg-1 for p-nitrophenyl-β-d-glucopyranoside, 1486 ± 68 U mg-1 for o-nitrophenyl-β-d-galactopyranoside, 2250 ± 86 U mg-1 for o-nitrophenyl-β-d-xylopyranoside and 175 ± 4 U mg-1 for lactose. A catalytic efficiency (kcat /Km ) of 3059 ± 122 mmol L-1 s-1 and Km value of 8.1 ± 0.08 mmol L-1 were displayed towards p-nitrophenyl-β-d-galactopyranoside. CONCLUSION As a result of its remarkable thermostability and high activity at high temperatures, this novel β-galactosidase may be useful for food and pharmaceutical applications. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Rebaone Letsididi
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
- National Food Technology Research Centre, Private Bag 008, Kanye, Botswana
| | - Hinawi Am Hassanin
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Marwa Yf Koko
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Jean B Ndayishimiye
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Tao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, 214122, China
| | - Bo Jiang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, 214122, China
| | - Timo Stressler
- University of Hohenheim, Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, Garbenstrasse 25, 70599, Stuttgart, Germany
| | - Lutz Fischer
- University of Hohenheim, Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, Garbenstrasse 25, 70599, Stuttgart, Germany
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, 214122, China
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Yang J, Di X, Wang M, Gao R. Gene clone and characterization of a novel thermostable β-galactosidase with transglycosylation activity from Thermotoga naphthophila RUK-10. Chem Res Chin Univ 2015. [DOI: 10.1007/s40242-015-5032-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Liu Z, Zhao C, Deng Y, Huang Y, Liu B. Characterization of a thermostable recombinant β-galactosidase from a thermophilic anaerobic bacterial consortium YTY-70. BIOTECHNOL BIOTEC EQ 2015. [DOI: 10.1080/13102818.2015.1015244] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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18
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Kong F, Wang Y, Cao S, Gao R, Xie G. Cloning, purification and characterization of a thermostable β-galactosidase from Thermotoga naphthophila RUK-10. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.02.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Tribst AAL, Augusto PED, Cristianini M. The effect of high pressure homogenization on the activity of a commercial β-galactosidase. J Ind Microbiol Biotechnol 2012; 39:1587-96. [PMID: 22911236 DOI: 10.1007/s10295-012-1179-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 07/19/2012] [Indexed: 11/29/2022]
Abstract
High pressure homogenization (HPH) has been proposed as a promising method for changing the activity and stability of enzymes. Therefore, this research studied the activity of β-galactosidase before and after HPH. The enzyme solution at pH values of 6.4, 7.0, and 8.0 was processed at pressures of up to 150 MPa, and the effects of HPH were determined from the residual enzyme activity measured at 5, 30, and 45 °C immediately after homogenization and after 1 day of refrigerated storage. The results indicated that at neutral pH the enzyme remained active at 30 °C (optimum temperature) even after homogenization at pressures of up to 150 MPa. On the contrary, when the β-galactosidase was homogenized at pH 6.4 and 8.0, a gradual loss of activity was observed, reaching a minimum activity (around 30 %) after HPH at 150 MPa and pH 8.0. After storage, only β-galactosidase that underwent HPH at pH 7.0 retained similar activity to the native sample. Thus, HPH did not affect the activity and stability of β-galactosidase only when the process was carried out at neutral pH; for the other conditions, HPH resulted in partial inactivation of the enzyme. Considering the use of β-galactosidase to produce low lactose milk, it was concluded that HPH can be applied with no deleterious effects on enzyme activity.
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Affiliation(s)
- Alline A L Tribst
- Department of Food Technology, School of Food Engineering, University of Campinas, Monteiro Lobato, 80, Campinas, SP 13083-862, Brazil.
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