Cyclodextrin glucanotransferase production by cell biocatalysts of alkaliphilic bacilli
Autor: | Nikolina Atanasova, Miroslava Safarikova, Tsvetina Kitayska, D. Yankov, Alexandra Tonkova |
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Rok vydání: | 2009 |
Předmět: |
chemistry.chemical_classification
Bacilli Environmental Engineering Chromatography Cyclodextrin biology Starch Biomedical Engineering Bioengineering biology.organism_classification Enzyme assay chemistry.chemical_compound Membrane Enzyme chemistry Yield (chemistry) biology.protein Biotechnology Cyclomaltodextrin glucanotransferase |
Zdroj: | Biochemical Engineering Journal. 46:278-285 |
ISSN: | 1369-703X |
DOI: | 10.1016/j.bej.2009.05.020 |
Popis: | Cells of obligated alkaliphiles Bacillus pseudalcaliphilus 20RF and Bacillus pseudalcaliphilus 8SB isolated from Bulgarian habitats, producers of cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19), were immobilized by three different techniques: on two types of polysulphone membranes; entrapped in agar-gel beads containing magnetite and by nano-particles of silanized magnetite covalently bound on the cell surface. The biocatalysts obtained demonstrated the opportunity for a significantly enhanced CGTase production compared to free cells for a long period of time (10 days semicontinuous cultivation) without impact on their mechanical stability. The cell membrane-biocatalysts exhibited the highest enzyme activity after 240 h repeated batch cultivation and retained 1.3–2.3-fold increase of the CGTase yield compared to free cells at the end of the process. Membrane biocatalysts were applied for a direct cyclodextrin (CD) production. The results obtained demonstrated the possibility of starch conversion into cyclodextrins by immobilized cells without using of crude or purified enzyme. The membrane biocatalysts of both obligated alkaliphiles formed mainly β- and γ-CDs after 6 h enzyme reaction at pH 9.0 of the reaction mixture. Under these conditions, the quantity of γ-CDs was a relative high, to 35–37% of the total CD amount. |
Databáze: | OpenAIRE |
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