title: A general method for selection of riboflavin-overproducing food grade micro-organisms.
abstract: BACKGROUND
  This study describes a strategy to select and isolate spontaneous riboflavin-overproducing strains of Lactobacillus (Lb.) plantarum, Leuconostoc (Lc.) mesenteroides and Propionibacterium (P.) freudenreichii.
  
  
  RESULTS
  The toxic riboflavin analogue roseoflavin was used to isolate natural riboflavin-overproducing variants of the food grade micro-organisms Lb. plantarum, Lc. mesenteroides and P. freudenreichii strains. The method was successfully employed for strains of all three species. The mutation(s) responsible for the observed overproduction of riboflavin were identified for isolates of two species.
  
  
  CONCLUSIONS
  Selection for spontaneous roseoflavin-resistant mutants was found to be a reliable method to obtain natural riboflavin-overproducing strains of a number of species commonly used in the food industry. This study presents a convenient method for deriving riboflavin-overproducing strains of bacterial starter cultures, which are currently used in the food industry, by a non-recombinant methodology. Use of such starter strains can be exploited to increase the vitamin content in certain food products.
authors.affiliation: Department of Microbiology and Biosciences Institute, National University of Ireland Cork, Western Road, Cork, Ireland. kaye.burgess@teagasc.ie
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Burgess
authors.forename: Eddy J
authors.initials: EJ
authors.lastname: Smid
authors.forename: Ger
authors.initials: G
authors.lastname: Rutten
authors.forename: Douwe
authors.initials: D
authors.lastname: van Sinderen