Expression of dar gene in lactic acid bacteria and effect on metabolite formation in feta-type cheese quality

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Date

2012

Journal Title

Journal ISSN

Volume Title

Publisher

Taylor & Francis

Abstract

The dar gene from Lactococcus lactis subsp. cremoris MG1363, encoding the enzyme diacetyl reductase (DAR) was cloned into the expression vector pMG36e under the control of the P32 promoter, and Lc. lactis MG1363 was transformed with this recombinant plasmid by electroporation. Metabolic end products (e. g., pyruvate, lactate, formate, acetoin) of this strain grown in glucose medium were analyzed by HPLC. The overexpression of the plasmid-encoded dar gene in Lc. lactis MG1363 led to the shift from homolactic to mixed acid fermentation and the production of a high level of acetoin, confirming the overexpression of the diacetyl reductase. In addition, the strains overexpressing dar gene and wild type were used as starter cultures in cheese. Different levels of metabolic end products were detected in cheese during the two weeks of ripening compared to the wild type strain.

Description

Keywords

Biotechnology & applied microbiology, Food science & technology, Dar gene, Diacetyl reductase, Lactic acid bacteria, Metaboic engineering, Acetoin, Lactococcus-lactis, Dna, Pathway, Cloning, Streptococci, Sequence, Bacteria (microorganisms), Lactococcus lactis, Lactococcus lactis subsp. cremoris, Bacteria, Cheeses, Cloning, Dna, Glucose, Lactic acid, Metabolic engineering, Metabolism, Cheese quality, Diacetyl, Electroporation, Expression vectors, Glucose medium, Metabolic end products, Mixed acid fermentation, Over-expression, Pyruvates, Recombinant plasmid, Starter cultures, Wild types, Wild-type strain, Gene expression

Citation

Karakaş A. Ş. ve Akyol, İ. (2012). "Expression of dar gene in lactic acid bacteria and effect on metabolite formation in feta-type cheese quality". Food Biotechnology, 26(1), 45-57.