Screening β-Fructofuranosidases mutant libraries to enhance the transglycosylation rates of β-(2→6) fructooligosaccharides
β-Fructofuranosidases can divert their hydrolytic activity towards transglycosylation for the synthesis of high value-added products, including prebiotic fructooligosaccharides (FOS). A directed evolution strategy has been employed to enhance the transferase rate of the β-fructofuranosidase (SoINV)...
| Authors: | , , , , |
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2011 |
| Country: | España |
| Institution: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repository: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/191189 |
| Online Access: | http://hdl.handle.net/10261/191189 |
| Access Level: | Open access |
| Keyword: | High-throughput screening Prebiotics Schwanniomyces occidentalis Transglycosylation β-(2→6) fructooligosaccharides Hydrolytic activity Directed evolution PCR Anion-exchange chromatography Amperometric detection Sucrose |
| Summary: | β-Fructofuranosidases can divert their hydrolytic activity towards transglycosylation for the synthesis of high value-added products, including prebiotic fructooligosaccharides (FOS). A directed evolution strategy has been employed to enhance the transferase rate of the β-fructofuranosidase (SoINV) from the Schwanniomyces occidentalis yeast for the production of β-(2→6)-linked FOS. To screen for transferase activity of the SoINV functionally expressed in Saccharomyces cerevisiae, a high-throughput screening protocol based on two colorimetric assays was validated (with coefficient of variance below 11%). Mutagenic libraries were constructed by error-prone PCR and clones showing higher glucose:fructose ratio with respect to the parental type were identified. Further analysis by anion-exchange chromatography coupled with pulsed amperometric detection helped to identify mutants with improved yields for the synthesis of β-(2→6) fructooligosaccharides. Selected mutants displayed transferase initial rates enhanced ∼2-fold over parent type, reaching production levels up to 47 g/L after 48 h of reaction for the formation of 6-kestose. © 2011 Bentham Science Publishers Ltd. |
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