Journal of Microbiology and Biotechnology

The Korean Society for Microbiology and Biotechnology (한국미생물·생명공학회)
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Cloning of the Endoglucanase Gene from Actinomyces sp. 40 in Escherichia coli and Some Properties of the Gene Products

  • Min, Hae-Ki (Department of Animal Science and Technology, College of Agriculture and Life Sciences, Seoul National University) ;
  • Choi, Yun-Jaie (Department of Animal Science and Technology, College of Agriculture and Life Sciences, Seoul National University) ;
  • Cho, Kwang-Keun (Department of Animal Science and Technology, College of Agriculture and Life Sciences, Seoul National University) ;
  • Ha, Jong-Kyu (Department of Animal Science and Technology, College of Agriculture and Life Sciences, Seoul National University) ;
  • Woo, Jung-Hee (Department of Animal Science and Technology, College of Agriculture and Life Sciences, Seoul National University)
  • Published : 1994.06.01
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Abstract

The $\beta$-1,4-endoglucanase gene from Actinomyces sp. 40 was cloned into Escherichia coli DH5$\alpha$ with pUC19. Chromosomal DNA from Actinomyces sp. 40 was cleaved with the restriction enzyme Sau3AI and ligated into pUC19 for the transformation of Escherichia coli DH5$\alpha$. Positive clones of $\beta$-1,4-endoglucanase gene were detected as the clear zones on a medium supplemented with carboxymethylcellulose (CMC). This transformant possessed a single plasmid, designated pDS1, which contained the vector DNA and a 3.5 kilobase (kb) Sau3AI insertion fragment encoding endoglucanase. The size of the cloned fragment was reduced to 2.0 kb. The endoglucanase activity produced by the E. coli DH5$\alpha$ (pDS6) was higher than that of Actinomyces sp. 40 strain. The optimum pH and temperature of the cloned enzyme were pH 4.0$\sim$5.0 and 55$^{\circ}C$, respectively. The cloned enzyme was stable at 55$^{\circ}C$ or below and in buffer ranging from pH 4.0 to 7.0. The enzyme degraded CMC but did not degrade xylan, cellobiose, and methyl-umbelliferylcellobiopyranoside (MUC).

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