title: Sol-gel immobilization as a suitable technique for enhancement of α-amylase activity ofAspergillus oryzaePP.
abstract: Bioencapsulation of microbial cells in silica-based matrices has proved to be a good strategy to enhance the biosynthetic capabilities and viability of bioproducers. In the present study, mycelium and pellet cultures of strainAspergillus oryzaePP were successfully immobilized in sol-gel hybrid matrices composed of tetraethylorthosilicate as an inorganic precursor, 5% (w/v) starch and 10 or 15% (w/v) polyethylene oxide, or 10% (w/v) calcium alginate as organic compounds. Biosynthetic activity of immobilized cultures was investigated by batch and fed-batch cultivation and the obtained results of 3042.04 IU cm-3were comparable with the enzyme activity of the free cell culture. Immobilized cultures retained their viability and biosynthetic capabilities up to the 744th h during fed-batch fermentation processes. Consequently, sol-gel encapsulation in hybrid matrices could be considered as a promising technique for immobilization ofAspergillus oryzaePP in order to increase the α-amylase production.
authors.affiliation: Faculty of Biology, Department of Biotechnology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria.
authors.forename: Yana
authors.initials: Y
authors.lastname: Evstatieva
authors.affiliation: Faculty of Biology, Department of Biotechnology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria.
authors.forename: Mariya
authors.initials: M
authors.lastname: Yordanova
authors.affiliation: Faculty of Metallurgy and Material Sciences, Department of Silicate Technology, University Of Chemical Technology and Metallurgy , Sofia , Bulgaria.
authors.forename: Georgi
authors.initials: G
authors.lastname: Chernev
authors.affiliation: Faculty of Biology, Department of Biotechnology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria.
authors.forename: Yanislava
authors.initials: Y
authors.lastname: Ruseva
authors.affiliation: Faculty of Biology, Department of Biotechnology, Sofia University 'St. Kliment Ohridski' , Sofia , Bulgaria.
authors.forename: Dilyana
authors.initials: D
authors.lastname: Nikolova
keywords: Aspergillus oryzae PP; amylase; immobilization; sol–gel hybrids