Activation of subtilisin Carlsberg in hexane by lyophilization in the presence of fumed silica

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Show simple item record Würges, Kerstin Pfromm, Peter H. Rezac, Mary E. Czermak, Peter 2009-12-04T02:27:24Z 2009-12-04T02:27:24Z 2009-12-04T02:27:24Z
dc.description.abstract Subtilisin Carlsberg (SC) was lyophilized from an aqueous buffer solution containing different amounts of unmodified commercial fumed silica. The activity of the enzyme/fumed silica preparation in hexane was compared to pure freeze-dried enzyme, and to a freeze-dried preparation reported in the literature with potassium chloride as additive. A sharp increase in enzyme activity was found to correlate with an increasing amount of fumed silica added to the enzyme solution prior to freeze-drying. A weight-ratio of 98.5wt% fumed silica relative to the mass of the final enzyme/fumed silica preparation led to about 130 fold increased activity of SC in hexane (when compared to pure lyophilized SC in hexane). This is about twice the activation effect compared to including potassium chloride in the buffer solution before freeze-drying [1]. When freezing at -20ºC instead of in liquid nitrogen, even better activation was observed with fumed silica. We hypothesize that the activation of SC in hexane by immobilization of the enzyme on fumed silica is likely due to the distribution of the enzyme on the large surface area of fumed silica. This alleviates mass transfer limitations. en_US
dc.relation.uri en_US
dc.subject Fumed silica en_US
dc.subject Activation of subtilisin Carlsberg en_US
dc.subject Immobilization en_US
dc.subject Hexane en_US
dc.subject Lyophilization en_US
dc.title Activation of subtilisin Carlsberg in hexane by lyophilization in the presence of fumed silica en_US
dc.type Article (author version) en_US 2005 en_US
dc.citation.doi 10.1016/j.molcatb.2005.04.008 en_US
dc.citation.epage 24 en_US
dc.citation.issn 0376-7388 en_US
dc.citation.issue 1-6 en_US
dc.citation.jtitle Journal of Molecular Catalysis B: Enzymatic en_US
dc.citation.spage 18 en_US
dc.citation.volume 34 en_US
dc.contributor.authoreid Pfromm en_US

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