Curdulana na imobilização de enzimas

Carbohydrate Polymers 56 (2004) 483–488 www.elsevier.com/locate/carbpol

Curdlan as a support matrix for immobilization of enzyme
Parag S. Saudagar*, Rekha S. Singhal
Food and Fermentation Technology Department, Institute of Chemical Technology, University of Mumbai, Matunga, Mumbai 400 019, India Received 1 August 2003; revised 21 February 2004; accepted 25 March 2004 Available online 10 May 2004

Abstract Curdlan, a high molecular weight extracellular b(1 ! 3) glucan produced by pure culture fermentation by Agrobacterium radiobacter NCIM 2443 contains large number of free hydroxyl groups. The reaction of hydroxyl containing supports with epichlorohydrin results in activated epoxy groups that can covalently link with available amino, hydroxyl, or sulfhydryl groups of enzymes, thereby immobilizing it. The present work reports on preparation of epoxy-activated matrix for immobilization of a model enzyme, porcine pancreatic lipase. The binding capacity of the matrix prepared by extraction of epoxy-activated curdlan by isopropyl alcohol was found to be 58.7% with about 0.6% loss of the enzyme activity during immobilization. Further, the specific activity of the enzyme increased marginally from 9.37 to 10.2. The corresponding value was 10.15 for a commercial sample of curdlan, epoxy-activated as for laboratory-isolated curdlan. Sepharose, the most widely used support matrix for the immobilization of enzymes was used for comparison in this study. q 2004 Elsevier Ltd. All rights reserved.
Keywords: Curdlan; Sepharose; Epoxy activation; Porcine pancreatic lipase; Support matrix; Immobilization

1. Introduction Curdlan, a high molecular weight polymer of glucose, b(1 ! 3)-glucan produced by pure culture fermentation from a nonpathogenic and nontoxicogenic strain of Agrobacterium biobar1 (identified as Alacligenes faecalis var. myxogenes) or Agrobacterium radiobacter (Nishinari & Zhanf, 2000) has recently been approved for food use by US FDA (Pszczola, 1997). Its