Earticle

초록

영어

A simple and convenient method of immobilizing dextransucrase via an affinity interaction is described, along with the use of this system to synthesize leucrose. Dextransucrase was produced in sucrose-free medium by fermenting a constitutive mutant of Leuconostoc mesenteroides NRRL B-512F and was separated using an ultrafiltration membrane. The purified enzyme was free of dextran polymer, which previously was always found with the sucrose-induced enzyme. Therefore, it was possible to immobilize the enzyme on dextran-based resins using an affinity interaction. Sephadex G-200 was the best resin for immobilizing the dextransucrase and gave a fast flow rate through the packed column. The immobilized dextransucrase retained more than 80% of its specific activity after immobilization (Km = 18.1 and mM and kcal = 450 sec-1 vs. 13.1 mM and 640 sec-1, respectively, for the free enzyme). The immobilized dextransucrase showed improved stability over a pH range of 4.0 to 6.5 and at moderately high temperatures over 40℃. When immobilized dextransucrase was used to synthesize leucrose via the transfer reaction with sucrose and fructose, about 74% of the sucrose was converted into leucrose after one day, and the half-life of the enzyme activity was 15 days. Regeneration of the resin by supplementation with dextransucrase enabled the recovery of the initial activity of the system, but both the reaction and the flow rate were lower, probably owing to the accumulation of dextran inside the resin.

목차

Abstract
 Introduction
 Materials and Methods
 Results and Discussion
 Acknowledgments
 References

키워드

저자

• Han, Nam-Soo [ epartment of Food Science and Technology, Research Center for Bioresource and Health, Chungbuk National University ] Corresponding author
• Kang, Seung-Yeon [ Department of Food Science and Technology, Research Center for Bioresource and Health, Chungbuk National University ]
• Lee, Soo-Bok [ Department of Food Nutrition, Yonsei University ]
• Robyt, John F. [ Department of Biochemistry and Biophysics, Iowa State University ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  Food Science and Biotechnology

• 간기

  격월간

• pISSN

  1226-7708

• 수록기간

  1992~2009

• 십진분류

  KDC 574 DDC 664