Riboflavin Production in Lactococcus lactis : Potential for In Situ Production of Vitamin-Enriched Foods

• DOI: 10.1128/aem.70.10.5769-5777.2004
• Publication Date: 2004-10-04T20:41:07Z
• Authors: Catherine Burgess; Mary O'Connell-Mo...; Wilbert Sybesma; Jeroen Hugenholtz; Douwe van Sinderen
• Keywords: DNA, Bacterial; 0301 basic medicine; 2. Zero hunger; Base Sequence; Riboflavin; Genetic Complementation Test; Molecular Sequence Data; Gene Expression; Lactococcus lactis; 03 medical and health sciences; Genes, Bacterial; Drug Resistance, Bacterial; Fermentation; Food, Fortified; Mutation; Operon; Escherichia coli; Genetic Engineering; Gene Deletion

ABSTRACT

This study describes the genetic analysis of the riboflavin (vitamin B 2 ) biosynthetic ( rib ) operon in the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NZ9000. Functional analysis of the genes of the L. lactis rib operon was performed by using complementation studies, as well as by deletion analysis. In addition, gene-specific genetic engineering was used to examine which genes of the rib operon need to be overexpressed in order to effect riboflavin overproduction. Transcriptional regulation of the L. lactis riboflavin biosynthetic process was investigated by using Northern hybridization and primer extension, as well as the analysis of roseoflavin-induced riboflavin-overproducing L. lactis isolates. The latter analysis revealed the presence of both nucleotide replacements and deletions in the regulatory region of the rib operon. The results presented here are an important step toward the development of fermented foods containing increased levels of riboflavin, produced in situ, thus negating the need for vitamin fortification.