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Kuroiwa T, Nakagawa Y, Takayanagi R, Kanazawa A. Chitosanase-immobilized magnetite-agar gel particles as a highly stable and reusable biocatalyst for enhanced production of physiologically active chitosan oligosaccharides. Enzyme Microb Technol 2024; 178:110443. [PMID: 38593516 DOI: 10.1016/j.enzmictec.2024.110443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/11/2024]
Abstract
A novel immobilized chitosanase was developed and utilized to produce chitosan oligosaccharides (COSs) via chitosan hydrolysis. Magnetite-agar gel particles (average particle diameter: 338 μm) were prepared by emulsifying an aqueous agar solution dispersing 200-nm magnetite particles with isooctane containing an emulsifier at 80 °C, followed by cooling the emulsified mixture. The chitosanase from Bacillus pumilus was immobilized on the magnetite-agar gel particles chemically activated by introducing glyoxyl groups with high immobilization yields (>80%), and the observed specific activity of the immobilized chitosanase was 16% of that of the free enzyme. This immobilized chitosanase could be rapidly recovered from aqueous solutions by applying magnetic force. The thermal stability of the immobilized chitosanase improved remarkably compared with that of free chitosanase: the deactivation rate constants at 35 °C of the free and immobilized enzymes were 8.1 × 10-5 and 3.9 × 10-8 s-1, respectively. This immobilized chitosanase could be reused for chitosan hydrolysis at 75 °C and pH 5.6, and 80% of its initial activity was maintained even after 10 cycles of use. COSs with a degree of polymerization (DP) of 2-7 were obtained using this immobilized chitosanase, and the product content of physiologically active COSs (DP ≥ 5) reached approximately 50%.
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Affiliation(s)
- Takashi Kuroiwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya-ku, Tokyo 158-8557, Japan.
| | - Yuta Nakagawa
- Department of Applied Chemistry, Faculty of Science and Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya-ku, Tokyo 158-8557, Japan
| | - Ryuichi Takayanagi
- Department of Applied Chemistry, Faculty of Science and Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya-ku, Tokyo 158-8557, Japan
| | - Akihiko Kanazawa
- Department of Applied Chemistry, Faculty of Science and Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya-ku, Tokyo 158-8557, Japan
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Costa JB, Nascimento LGL, Martins E, De Carvalho AF. Immobilization of the β-galactosidase enzyme by encapsulation in polymeric matrices for application in the dairy industry. J Dairy Sci 2024:S0022-0302(24)01019-1. [PMID: 39033918 DOI: 10.3168/jds.2024-24892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 06/24/2024] [Indexed: 07/23/2024]
Abstract
Lactose intolerance affects approximately 65% of the global adult population, leading to the demand for lactose-free products. The enzyme β-galactosidase (βG) is commonly used in the industry to produce such products, but its recovery after lactose hydrolysis is challenging. In this scenario, the study aims to encapsulate βG within capsules, varying in dimensions and wall materials, to ensure their suitability for efficient industrial recovery. The enzyme βG was encapsulated through ionic gelation using alginate and its blends with pectin, maltodextrin, starch, or whey protein as wall materials. The capsules produced underwent evaluation for encapsulation efficiency, release profiles, activity of the βG enzyme, and the decline in enzyme activity when reused over multiple cycles. Alginate at 5% wt/vol concentrations, alone or combined with polymers such as maltodextrin, starch, or whey protein, achieved encapsulation efficiencies of approximately 98%, 98%, 80%, and 88%, respectively. The corresponding enzyme recovery rates were 34%, 19%, 31%, and 48%. Capsules made with an alginate-pectin blend exhibited no significant hydrolysis and maintained an encapsulation efficiency of 79%. Encapsulation with alginate alone demonstrated on poor retention of enzyme activity, showing a loss of 74% after just 4 cycles of reuse. Conversely, when alginate was mixed with starch or whey protein concentrate, the loss of enzyme activity was less than 40% after 4 reuses. These results highlight the benefits of combining encapsulation materials to improve enzyme recovery and reuse, offering potential economic advantages for the dairy industry.
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Affiliation(s)
- Jessiele Barbosa Costa
- Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa (UFV), 36570-900 Viçosa, Minas Gerais, Brazil
| | - Luis Gustavo Lima Nascimento
- Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa (UFV), 36570-900 Viçosa, Minas Gerais, Brazil
| | - Evandro Martins
- Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa (UFV), 36570-900 Viçosa, Minas Gerais, Brazil
| | - Antônio Fernandes De Carvalho
- Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa (UFV), 36570-900 Viçosa, Minas Gerais, Brazil..
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Chalella Mazzocato M, Jacquier JC. Recent Advances and Perspectives on Food-Grade Immobilisation Systems for Enzymes. Foods 2024; 13:2127. [PMID: 38998633 PMCID: PMC11241248 DOI: 10.3390/foods13132127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/27/2024] [Accepted: 07/01/2024] [Indexed: 07/14/2024] Open
Abstract
The use of enzyme immobilisation is becoming increasingly popular in beverage processing, as this method offers significant advantages, such as enhanced enzyme performance and expanded applications, while allowing for easy process termination via simple filtration. This literature review analysed approximately 120 articles, published on the Web of Science between 2000 and 2023, focused on enzyme immobilisation systems for beverage processing applications. The impact of immobilisation on enzymatic activity, including the effects on the chemical and kinetic properties, recyclability, and feasibility in continuous processes, was evaluated. Applications of these systems to beverage production, such as wine, beer, fruit juices, milk, and plant-based beverages, were examined. The immobilisation process effectively enhanced the pH and thermal stability but caused negative impacts on the kinetic properties by reducing the maximum velocity and Michaelis-Menten constant. However, it allowed for multiple reuses and facilitated continuous flow processes. The encapsulation also allowed for easy process control by simplifying the removal of the enzymes from the beverages via simple filtration, negating the need for expensive heat treatments, which could result in product quality losses.
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Affiliation(s)
- Marcella Chalella Mazzocato
- School of Agriculture and Food Science, Institute of Food and Health, University College Dublin (UCD), Belfield, D04 V1W8 Dublin, Ireland
| | - Jean-Christophe Jacquier
- School of Agriculture and Food Science, Institute of Food and Health, University College Dublin (UCD), Belfield, D04 V1W8 Dublin, Ireland
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Belkova M, Janegova T, Hrabarova E, Nahalka J. Physiologically Aggregated LacZ Applied in Trehalose Galactosylation in a Recycled Batch Mode. Life (Basel) 2023; 13:1619. [PMID: 37629477 PMCID: PMC10455999 DOI: 10.3390/life13081619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/17/2023] [Accepted: 07/22/2023] [Indexed: 08/27/2023] Open
Abstract
Galactooligosaccharides obtained via β-galactosidase transgalactosylation have health-promoting properties and are widely recognized as effective prebiotics. Trehalose-based galactooligosaccharides could be introduced into food and pharmaceutical industries similarly to trehalose. In light of this, new technological approaches are needed. Recently, in vivo enzyme immobilizations for recombinant proteins have been introduced, and physiological aggregation into active inclusion bodies (aIBs) has emerged as one such method of in vivo immobilization. To prepare LacZ β-galactosidase in the form of aIBs, we used a short 10 amino acid aggregation-prone tag. These native protein particles were simply washed from the cell lysate and applied in trehalose galactosylation in a recycled batch mode. In this study, aIBs entrapped in alginate beads, encapsulated in alginate/cellulose sulfate/poly(methylene-co-guanidine) capsules and magnetized were compared with free aIBs. Alginate/cellulose sulfate/PMCG capsules showed more suitable properties and applicability for biotransformation of trehalose at its high concentration (25%, w/v) and elevated temperature (50 °C).
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Affiliation(s)
- Martina Belkova
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
| | - Tatiana Janegova
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
| | - Eva Hrabarova
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
| | - Jozef Nahalka
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
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Kalathinathan P, Sain A, Pulicherla K, Kodiveri Muthukaliannan G. A Review on the Various Sources of β-Galactosidase and Its Lactose Hydrolysis Property. Curr Microbiol 2023; 80:122. [PMID: 36862237 DOI: 10.1007/s00284-023-03220-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 02/10/2023] [Indexed: 03/03/2023]
Abstract
β-Galactosidase is a glycoside hydrolase enzyme that possesses both hydrolytic and transgalactosylation properties and has several benefits and advantages in the food and dairy industries. The catalytic process of β-galactosidase involves the transfer of a sugar residue from a glycosyl donor to an acceptor via a double-displacement mechanism. Hydrolysis prevails when water acts as an acceptor, resulting in the production of lactose-free products. Transgalactosylation prevails when lactose acts as an acceptor, resulting in the production of prebiotic oligosaccharides. β-Galactosidase is also obtained from many sources including bacteria, yeast, fungi, plants, and animals. However, depending on the origin of the β-galactosidase, the monomer composition and their bonds may differ, thereby influencing their properties and prebiotic efficacy. Thus, the increasing demand for prebiotics in the food industry and the search for new oligosaccharides have compelled researchers to search for novel sources of β-galactosidase with diverse properties. In this review, we discuss the properties, catalytic mechanisms, various sources and lactose hydrolysis properties of β-galactosidase.
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Affiliation(s)
- Pooja Kalathinathan
- School of BioSciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Avtar Sain
- Centre for Bio-Separation Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
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Investigation of the immobilized methyl parathion hydrolase from Azohydromonas australica onto metal-organic frameworks (MOFs) MIL-88A. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Nickel-Functionalized Chitosan for the Oriented Immobilization of Histidine-Tagged Enzymes: A Promising Support for Food Bioprocess Applications. Catal Letters 2022. [DOI: 10.1007/s10562-021-03912-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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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9
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Schulz P, Rizvi SS. Hydrolysis of Lactose in Milk: Current Status and Future Products. FOOD REVIEWS INTERNATIONAL 2021. [DOI: 10.1080/87559129.2021.1983590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Patrick Schulz
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Syed S.H. Rizvi
- Department of Food Science, Cornell University, Ithaca, New York, USA
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10
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Hackenhaar CR, Spolidoro LS, Flores EEE, Klein MP, Hertz PF. Batch synthesis of galactooligosaccharides from co-products of milk processing using immobilized β-galactosidase from Bacillus circulans. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.102136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Hutchins DA, Noh J, Kenealey JD. Activity, stability, and binding capacity of β-galactosidase immobilized on electrospun nylon-6 fiber membrane. J Dairy Sci 2021; 104:3888-3898. [PMID: 33589258 DOI: 10.3168/jds.2020-19453] [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: 08/11/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022]
Abstract
In this research, we explored various immobilized enzyme support materials, including the novel nylon-6 fiber membrane (NFM), and evaluated the increase in surface area and its effect on enzyme binding potential. We also manipulated incubation and reaction conditions and assessed the subsequent effects on activity and stability of β-galactosidase, with comparisons between various solid support materials and free (dissolved) enzyme. Nylon-6 fiber membranes were created by electrospinning and were compared with other materials as solid supports for enzyme binding. The other materials included polyvinylidene fluoride 5-kDa nanofiltration dairy membranes, nylon-6 pellets, and silica glass beads. Scanning electron microscopy revealed the large surface area of NFM, which correlated with greater enzyme activity compared with the relatively flatter surfaces of the other solid support materials. Enzyme activity was measured spectrophotometrically with the color-changing substrate o-nitrophenyl-β-d-galactopyranoside. Compared with the other solid supports, NFM had greater maximum enzyme binding potential. Across pH conditions ranging from 3.5 to 6.0 (including the optimal pH of 4.0-5.0), enzyme activity was maintained on the membrane-immobilized samples, whereas free enzyme did not maintain activity. Altering the storage temperature (4, 22, and 50°C) affected enzyme stability (i.e., the ability of the enzyme to maintain activity over time) of free and polyvinylidene fluoride membrane samples. However, NFM samples maintained stability across the varying storage temperatures. Increasing the immobilization solution enzyme concentration above the maximum enzyme binding capacity had no significant effect on enzyme stability for membrane-immobilized samples; however, both had lower mean stability than free enzyme by approximately 74%. With further development, β-galactosidase immobilized on NFM or other membranes could be used in continuous processing in the dairy industry for a combination of filtration and lactose hydrolysis-creating products that are reduced in lactose and increased in sweetness, with no requirement for "added sugars" on the nutrition label and no enzyme listed as final product ingredient.
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Affiliation(s)
- D A Hutchins
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602
| | - J Noh
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602
| | - J D Kenealey
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602.
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Lima PC, Gazoni I, de Carvalho AMG, Bresolin D, Cavalheiro D, de Oliveira D, Rigo E. β-galactosidase from Kluyveromyces lactis in genipin-activated chitosan: An investigation on immobilization, stability, and application in diluted UHT milk. Food Chem 2021; 349:129050. [PMID: 33556730 DOI: 10.1016/j.foodchem.2021.129050] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 12/19/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023]
Abstract
The objective of this research was to evaluate the immobilization of the enzyme β-galactosidase in a genipin-activated chitosan support. The influence of the number of spheres and substrate concentration on immobilization yield (IY) and enzyme activity (EA) was analyzed using experimental design. Thermal, operational and storage stabilities were assessed, and the enzymatic derivatives were characterized by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The TGA showed that the enzymatic derivatives kept their thermal behavior, and the SEM images revealed smooth surfaces in all the spheres. The optimized conditions for the immobilization process were 4.57 mg·mL-1 of spheres and a substrate concentration of 10 mM (IY = 84.13%; EA = 24.97 U·g-1). Thermal stability was enhanced at 10 and 37 °C, enabling four successive cycles of lactose hydrolysis in diluted UHT milk. Therefore, the immobilized enzyme in genipin-activated chitosan has potential for lactose hydrolysis and applications in the food industry.
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Affiliation(s)
- Pâmela Cristina Lima
- Department of Food and Chemical Engineering, Santa Catarina State University, Pinhalzinho, SC 89870-000, Brazil
| | - Isadora Gazoni
- Department of Food and Chemical Engineering, Santa Catarina State University, Pinhalzinho, SC 89870-000, Brazil
| | | | - Daniela Bresolin
- Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC 88040-900, Brazil
| | - Darlene Cavalheiro
- Department of Food and Chemical Engineering, Santa Catarina State University, Pinhalzinho, SC 89870-000, Brazil.
| | - Débora de Oliveira
- Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC 88040-900, Brazil.
| | - Elisandra Rigo
- Department of Food and Chemical Engineering, Santa Catarina State University, Pinhalzinho, SC 89870-000, Brazil.
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Guerrero C, Aburto C, Súarez S, Vera C, Illanes A. Improvements in the production of Aspergillus oryzae β-galactosidase crosslinked aggregates and their use in repeated-batch synthesis of lactulose. Int J Biol Macromol 2019; 142:452-462. [PMID: 31676297 DOI: 10.1016/j.ijbiomac.2019.09.117] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/16/2019] [Accepted: 09/16/2019] [Indexed: 01/15/2023]
Abstract
Aspergillus oryzae β-galactosidase was immobilized by aggregation and crosslinking, obtaining catalysts (CLAGs) well-endowed for lactulose synthesis. Type and concentration of the precipitating agent were determinants of immobilization yield, specific activity and thermal stability. CLAGs with specific activities of 64,007, 48,374 and 44,560 IUH g-1 were obtained using 50% v/v methanol, ethanol and propanol as precipitating agents respectively, with immobilization yields over 90%. Lactulose synthesis was conducted at 50 °C, pH 4.5, 50% w/w total sugars, 200 IUH g-1 of enzyme and fructose/lactose molar ratio of 8 in batch and repeated-batch operation. Lactulose yields were 0.19 g g-1 and 0.24 g g-1 for fructose to lactose molar ratios of 4 mol mol-1 and 8 mol mol-1 while selectivities were 3.3 mol mol-1 and 6.6 mol mol-1 respectively for CLAGs obtained by ethanol and propanol precipitation. Based on these results, both CLAGs were selected for the synthesis in repeated-batch mode. The cumulative mass of lactulose in repeated-batch was higher with CLAGs produced by ethanol and propanol precipitation than with the free enzyme. 86 and 93 repeated-batches could have been respectively performed with those CLAGs considering a catalyst replacement criterion of 50% of residual activity, as determined by simulation.
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Affiliation(s)
- Cecilia Guerrero
- School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso (PUCV), Valparaíso, Chile.
| | - Carla Aburto
- School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso (PUCV), Valparaíso, Chile
| | - Sebastián Súarez
- 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
| | - Andrés Illanes
- School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso (PUCV), Valparaíso, Chile
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