Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media
Three microbial galactosidases, Aspergillus oryzae, Escherichia coli and Kluyveromyces marxianus β-galactosidase, were used as catalysts for transgalactosylation synthesis of alkyl-β-galactosides in single-phased alcohol media. Their selectivity towards different alcohol nucleophiles was quantified...
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| Format: | Article |
| Language: | English |
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University of Zagreb Faculty of Food Technology and Biotechnology
2008-01-01
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| Series: | Food Technology and Biotechnology |
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| Online Access: | http://hrcak.srce.hr/file/41735 |
| _version_ | 1827611030783524864 |
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| author | Eleonora Winkelhausen Slobodanka Kuzmanova Irina Mladenoska |
| author_facet | Eleonora Winkelhausen Slobodanka Kuzmanova Irina Mladenoska |
| author_sort | Eleonora Winkelhausen |
| collection | DOAJ |
| description | Three microbial galactosidases, Aspergillus oryzae, Escherichia coli and Kluyveromyces marxianus β-galactosidase, were used as catalysts for transgalactosylation synthesis of alkyl-β-galactosides in single-phased alcohol media. Their selectivity towards different alcohol nucleophiles was quantified by determining the transgalactosylation/hydrolysis ratio in the water/alcohol mixtures containing water in concentrations below the level of saturation. p-Nitrophenyl-β-galactoside was used as a glycosyl donor at a concentration of 10 mM. Both the total reaction rate (transgalactosylation+hydrolysis) and the ratio between the transgalactosylation (alcoholysis) and hydrolysis increased with the increase of water activity. Although the A. oryzae β-galactosidase showed relatively low total activity (3.13 μmol/(min·mg protein)), it exhibited the highest selectivity towards the hexanol nucleophile among the examined enzymes (0.65). The selectivity values in all the examined cases were below one, which implies that the hydrolysis, and not the synthesis, was the dominating reaction. The total reaction rate (transgalactosylation+hydrolysis) was strongly affected by the water activity, and for the specific water activity in the different alcohols, it increased in the following order: n-octanol, n-hexanol, n-butanol. |
| first_indexed | 2024-03-09T07:59:19Z |
| format | Article |
| id | doaj.art-190066104a414fd5b210391003f8e434 |
| institution | Directory Open Access Journal |
| issn | 1330-9862 1334-2606 |
| language | English |
| last_indexed | 2024-03-09T07:59:19Z |
| publishDate | 2008-01-01 |
| publisher | University of Zagreb Faculty of Food Technology and Biotechnology |
| record_format | Article |
| series | Food Technology and Biotechnology |
| spelling | doaj.art-190066104a414fd5b210391003f8e4342023-12-03T00:48:07ZengUniversity of Zagreb Faculty of Food Technology and BiotechnologyFood Technology and Biotechnology1330-98621334-26062008-01-01463311316Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol MediaEleonora Winkelhausen0Slobodanka Kuzmanova1Irina Mladenoska2Ss. Cyril and Methodius University, Faculty of Technology and Metallurgy, Department of Biotechnology and Food Technology, Rudjer Boskovic 16,MK-1000 Skopje, Republic of MacedoniaSs. Cyril and Methodius University, Faculty of Technology and Metallurgy, Department of Biotechnology and Food Technology, Rudjer Boskovic 16,MK-1000 Skopje, Republic of MacedoniaSs. Cyril and Methodius University, Faculty of Technology and Metallurgy, Department of Biotechnology and Food Technology, Rudjer Boskovic 16,MK-1000 Skopje, Republic of MacedoniaThree microbial galactosidases, Aspergillus oryzae, Escherichia coli and Kluyveromyces marxianus β-galactosidase, were used as catalysts for transgalactosylation synthesis of alkyl-β-galactosides in single-phased alcohol media. Their selectivity towards different alcohol nucleophiles was quantified by determining the transgalactosylation/hydrolysis ratio in the water/alcohol mixtures containing water in concentrations below the level of saturation. p-Nitrophenyl-β-galactoside was used as a glycosyl donor at a concentration of 10 mM. Both the total reaction rate (transgalactosylation+hydrolysis) and the ratio between the transgalactosylation (alcoholysis) and hydrolysis increased with the increase of water activity. Although the A. oryzae β-galactosidase showed relatively low total activity (3.13 μmol/(min·mg protein)), it exhibited the highest selectivity towards the hexanol nucleophile among the examined enzymes (0.65). The selectivity values in all the examined cases were below one, which implies that the hydrolysis, and not the synthesis, was the dominating reaction. The total reaction rate (transgalactosylation+hydrolysis) was strongly affected by the water activity, and for the specific water activity in the different alcohols, it increased in the following order: n-octanol, n-hexanol, n-butanol.http://hrcak.srce.hr/file/41735transgalactosylation/hydrolysis ratiosβ-galactosidasesalkyl-β-galactoside synthesissingle-phased mediaselectivity factors |
| spellingShingle | Eleonora Winkelhausen Slobodanka Kuzmanova Irina Mladenoska Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media Food Technology and Biotechnology transgalactosylation/hydrolysis ratios β-galactosidases alkyl-β-galactoside synthesis single-phased media selectivity factors |
| title | Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media |
| title_full | Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media |
| title_fullStr | Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media |
| title_full_unstemmed | Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media |
| title_short | Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media |
| title_sort | transgalactosylation hydrolysis ratios of various β galactosidases catalyzing alkyl β galactoside synthesis in single phased alcohol media |
| topic | transgalactosylation/hydrolysis ratios β-galactosidases alkyl-β-galactoside synthesis single-phased media selectivity factors |
| url | http://hrcak.srce.hr/file/41735 |
| work_keys_str_mv | AT eleonorawinkelhausen transgalactosylationhydrolysisratiosofvariousbgalactosidasescatalyzingalkylbgalactosidesynthesisinsinglephasedalcoholmedia AT slobodankakuzmanova transgalactosylationhydrolysisratiosofvariousbgalactosidasescatalyzingalkylbgalactosidesynthesisinsinglephasedalcoholmedia AT irinamladenoska transgalactosylationhydrolysisratiosofvariousbgalactosidasescatalyzingalkylbgalactosidesynthesisinsinglephasedalcoholmedia |