Glucansucrases from lactic acid bacteria as biocatalysts for multi-ring catechol glucosylation
| Autor: | Matthias Hochgürtel, Ulrich Schörken, Johannes Nolte, Alexander Kempa |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Catechol biology 010405 organic chemistry Chemistry food and beverages Catechin Green tea Ring (chemistry) biology.organism_classification 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Lactic acid chemistry.chemical_compound 010608 biotechnology Glucansucrase biology.protein Acceptor reaction Bacteria Biotechnology |
| Zdroj: | Biocatalysis and Biotransformation. 39:48-60 |
| ISSN: | 1029-2446 1024-2422 |
| Popis: | Catechins are the major group of bioactive flavanols in green tea and cacao. 17 glucansucrase-active strains were identified from a set of 41 lactic acid bacteria, which were able to glucosylate (+)-catechin in a non-natural acceptor reaction. In total cell free extracts of 12 Leuconostoc and 5 Weissella strains were active on catechin and also 8 cell fractions exhibited catechin glucosylation activity. Six enzymes were selected for further evaluation and enriched up to 37 fold in yields of at least 40%. Glucansucrase of L. citreum DSM 5577 was the most efficient biocatalyst for (+)-catechin transformation with conversions of >40% after 24 h. NMR analysis of the major reaction product confirmed the (+)-catechin-4′-O-α-d-glucoside. Only L. kimchi B-65337 produced a second catechin monoglucoside. Four out of six glucansucrases glucosylated esculetin and all enzymes were active on haematoxylin. Glucansucrases of L. citreum DSM 5577, L. kimchi B-65337 and W. beninensis DSM 22752 were the best suited biocatalysts with conversions of >30% for esculetin and >60% for haematoxylin. W. beninensis DSM 22752 glucansucrase produced 89% haematoxylin glucosides without process optimization. L. kimchi B-65337 and W. beninensis DSM 22752 synthesized >40% diglucosides with the bifunctional haematoxylin. NMR analysis of the purified esculetin products confirmed formation of the 6-O-α-d- and 7-O-α-d-glucosides. Also two haematoxylin monoglucosides were identified as the 9-O-α-d- and 3-O-α-d-glucosides. |
| Databáze: | OpenAIRE |
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