A general method for selection of riboflavin-overproducing food grade micro-organisms
1 Department of Microbiology and Biosciences Institute, National University of Ireland Cork, Western Road, Cork, Ireland
2 NIZO Food Research, PO Box 20, 6710 BA Ede, The Netherlands
3 Alimentary Pharmabiotic Centre, Biosciences Institute, National University of Ireland Cork, Western Road, Cork, Ireland
4 current address: Dept of Food Safety, Teagasc-Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland
Microbial Cell Factories 2006, 5:24 doi:10.1186/1475-2859-5-24Published: 18 July 2006
This study describes a strategy to select and isolate spontaneous riboflavin-overproducing strains of Lactobacillus (Lb.) plantarum, Leuconostoc (Lc.) mesenteroides and Propionibacterium (P.) freudenreichii.
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.
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.