Expression of a β-galactosidase gene fromLactobacillus sakeinEscherichia coli

✍ Scribed by Maria J. Torres; Byong H. Lee

• Publisher: Springer Netherlands
• Year: 1995
• Tongue: English
• Weight: 415 KB
• Volume: 17
• Category: Article
• ISSN: 0141-5492
• DOI: 10.1007/bf00130352

✦ Synopsis

A B-galactosidase gene from Lactobacillus sake coding for lactose hydrolysis was cloned and expressed in Escherichia coli. Chromosomal DNA from L. 'sa& was partially digested with the restriction enzyme SaDAI, and the 3-6 Kb fragment was ligated to the cloning vector pSP72 digested with BarnHI. One E. coli transformant expressing B-galactosidase was isolated on X-gal plates. It contained a plasmid with an insertion of approx. 4 Kb. The restriction map of the recombinant plasmid was constructed. The characteristics of the recombinant B-galactosidase were compared with those of the wild type. The optima pH and temperature for both enzymes was 6.5 and 5O"C, respectively. Stability of the enzymes at different temperatures and activity on lactose were determined.