This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Swindell, S. R. Articles by Gasson, M. J. Search for Related Content PubMed PubMed Citation Articles by Swindell, S. R. Articles by Gasson, M. J. Agricola Articles by Swindell, S. R. Articles by Gasson, M. J.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol., 07 1996, 2641-2643, Vol 62, No. 7
Copyright © 1996, American Society for Microbiology

Genetic manipulation of the pathway for diacetyl metabolism in Lactococcus lactis

SR Swindell, KH Benson, HG Griffin, P Renault, SD Ehrlich and MJ Gasson
Institute of Food Research, Colney, United Kingdom.

Diacetyl is an important food flavor compound produced by certain strains of citrate-metabolizing lactic acid bacteria. Citrate is converted to pyruvate, from which diacetyl is produced via intermediate alpha-acetolactate. This paper reports the cloning and analysis of the gene (aldB) encoding alpha-acetolactate decarboxylase from Lactococcus lactis MG1363. Deletion of the MG1363 chromosomal aldB gene was achieved by double crossover homologous recombination. The mutant strain was found to produce diacetyl; alpha-acetolactate decarboxylase activity was eliminated. Overexpression of the cloned ilvBN genes (encoding an alpha-acetolactate synthase) in the aldB deletion strain produced even higher levels of alpha-acetolactate, acetoin, and diacetyl.