Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose
The use of ketohexose isomerases is a powerful tool in lactose whey processing, but these enzymes can be very sensitive and expensive. Development of immobilized/stabilized biocatalysts could be a further option to improve the process. In this work, β-galactosidase from Bacillus circulans, l-arabino...
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| Format: | Article |
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MDPI AG
2017-02-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/22/2/284 |
| _version_ | 1818256706296086528 |
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| author | Pedro Torres Francisco Batista-Viera |
| author_facet | Pedro Torres Francisco Batista-Viera |
| author_sort | Pedro Torres |
| collection | DOAJ |
| description | The use of ketohexose isomerases is a powerful tool in lactose whey processing, but these enzymes can be very sensitive and expensive. Development of immobilized/stabilized biocatalysts could be a further option to improve the process. In this work, β-galactosidase from Bacillus circulans, l-arabinose (d-galactose) isomerase from Enterococcus faecium, and d-xylose (d-glucose) isomerase from Streptomyces rubiginosus were immobilized individually onto Eupergit C and Eupergit C 250 L. Immobilized activity yields were over 90% in all cases. With the purpose of increasing thermostability of derivatives, two post-immobilization treatments were performed: alkaline incubation to favor the formation of additional covalent linkages, and blocking of excess oxirane groups by reacting with glycine. The greatest thermostability was achieved when alkaline incubation was carried out for 24 h, producing l-arabinose isomerase-Eupergit C derivatives with a half-life of 379 h and d-xylose isomerase-Eupergit C derivatives with a half-life of 554 h at 50 °C. Preliminary assays using immobilized and stabilized biocatalysts sequentially to biotransform lactose at pH 7.0 and 50 °C demonstrated improved performances as compared with soluble enzymes. Further improvements in ketohexose productivities were achieved when the three single-immobilizates were incubated simultaneously with lactose in a mono-reactor system. |
| first_indexed | 2024-12-12T17:32:01Z |
| format | Article |
| id | doaj.art-c3e7a0337d9c4e3f9903134157e23e50 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-12T17:32:01Z |
| publishDate | 2017-02-01 |
| publisher | MDPI AG |
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| series | Molecules |
| spelling | doaj.art-c3e7a0337d9c4e3f9903134157e23e502022-12-22T00:17:21ZengMDPI AGMolecules1420-30492017-02-0122228410.3390/molecules22020284molecules22020284Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of LactosePedro Torres0Francisco Batista-Viera1Cátedra de Bioquímica, Departamento de Biociencias, Facultad de Química, Universidad de la República, Gral Flores 2124, 11800 Montevideo, UruguayCátedra de Bioquímica, Departamento de Biociencias, Facultad de Química, Universidad de la República, Gral Flores 2124, 11800 Montevideo, UruguayThe use of ketohexose isomerases is a powerful tool in lactose whey processing, but these enzymes can be very sensitive and expensive. Development of immobilized/stabilized biocatalysts could be a further option to improve the process. In this work, β-galactosidase from Bacillus circulans, l-arabinose (d-galactose) isomerase from Enterococcus faecium, and d-xylose (d-glucose) isomerase from Streptomyces rubiginosus were immobilized individually onto Eupergit C and Eupergit C 250 L. Immobilized activity yields were over 90% in all cases. With the purpose of increasing thermostability of derivatives, two post-immobilization treatments were performed: alkaline incubation to favor the formation of additional covalent linkages, and blocking of excess oxirane groups by reacting with glycine. The greatest thermostability was achieved when alkaline incubation was carried out for 24 h, producing l-arabinose isomerase-Eupergit C derivatives with a half-life of 379 h and d-xylose isomerase-Eupergit C derivatives with a half-life of 554 h at 50 °C. Preliminary assays using immobilized and stabilized biocatalysts sequentially to biotransform lactose at pH 7.0 and 50 °C demonstrated improved performances as compared with soluble enzymes. Further improvements in ketohexose productivities were achieved when the three single-immobilizates were incubated simultaneously with lactose in a mono-reactor system.http://www.mdpi.com/1420-3049/22/2/284β-galactosidase">l-arabinose isomerase">d-glucose isomeraseenzyme immobilization">d-tagatose">d-fructose |
| spellingShingle | Pedro Torres Francisco Batista-Viera Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose Molecules β-galactosidase ">l-arabinose isomerase ">d-glucose isomerase enzyme immobilization ">d-tagatose ">d-fructose |
| title | Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose |
| title_full | Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose |
| title_fullStr | Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose |
| title_full_unstemmed | Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose |
| title_short | Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose |
| title_sort | immobilized trienzymatic system with enhanced stabilization for the biotransformation of lactose |
| topic | β-galactosidase ">l-arabinose isomerase ">d-glucose isomerase enzyme immobilization ">d-tagatose ">d-fructose |
| url | http://www.mdpi.com/1420-3049/22/2/284 |
| work_keys_str_mv | AT pedrotorres immobilizedtrienzymaticsystemwithenhancedstabilizationforthebiotransformationoflactose AT franciscobatistaviera immobilizedtrienzymaticsystemwithenhancedstabilizationforthebiotransformationoflactose |