Production, characterization and (co-)immobilization of dextranase from Penicillium aculeatum
Fermentation kinetics of Penicillium aculeatum ATCC 10409 demonstrated that fungal growth and dextranase release are decoupled. Inoculation by conidia or mycelia resulted in identical kinetics. Two new isoenzymes of the dextranase were characterized regarding their kinetic constants, pI, MW, activation energy and stabilities. The larger enzyme was 3-fold more active (turnover number: 2,230 ± 97 s−1). Pre-treatment of bentonite with H2O2 did not affect adsorption characteristics of dextranase. Enzyme to bentonite ratios above 0.5:1 (w/w) resulted in a high conservation of activity upon adsorption. Furthermore, dextranase could be used in co-immobilizates for the direct conversion of sucrose into isomalto-oligosaccharides (e.g. isomaltose). Yields of co-immobilizates were 2–20 times that of basic immobilizates, which consist of dextransucrase without dextranase.
KeywordsAdsorption Bentonite Co-immobilization Dextranase Penicillium aculeatum
The authors would like to thank the German Research Foundation DFG that supported this project via a grant to the collaborative research centre SFB 578 “From gene to product”.
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