title: Multivitamin production in Lactococcus lactis using metabolic engineering.
abstract: The dairy starter bacterium Lactococcus lactis has the potential to synthesize both folate (vitamin B11) and riboflavin (vitamin B2). By directed mutagenesis followed by selection and metabolic engineering we have modified two complicated biosynthetic pathways in L. lactis resulting in simultaneous overproduction of both folate and riboflavin: Following exposure to the riboflavin analogue roseoflavin we have isolated a spontaneous mutant of L. lactis strain NZ9000 that was changed from a riboflavin consumer into a riboflavin producer. This mutant contained a single base change in the regulatory region upstream of the riboflavin biosynthetic genes. By the constitutive overproduction of GTP cyclohydrolase I in this riboflavin-producing strain, the production of folate was increased as well. Novel foods, enriched through fermentation using these multivitamin-producing starters, could compensate the B-vitamin-deficiencies that are common even in highly developed countries and could specifically be used in dietary foods for the large fraction of the Caucasian people (10-15%) with mutations in the methylene tetrahydrofolate reductase (MTHFR).
authors.affiliation: Department of Flavor, Nutrition and Natural Ingredients, Wageningen Centre for Food Sciences, NIZO food research, Kernhemseweg 2, P.O. Box 20, 6710 BA Ede, The Netherlands.
authors.forename: Wilbert
authors.initials: W
authors.lastname: Sybesma
authors.forename: Catherine
authors.initials: C
authors.lastname: Burgess
authors.forename: Marjo
authors.initials: M
authors.lastname: Starrenburg
authors.forename: Douwe
authors.initials: D
authors.lastname: van Sinderen
authors.forename: Jeroen
authors.initials: J
authors.lastname: Hugenholtz
mesh_terms: D005492:Folic Acid / Q000096:biosynthesis* / Q000235:genetics*; D024861:Genetic Enhancement / Q000379:methods; D013294:Lactococcus lactis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000378:metabolism; D012256:Riboflavin / Q000096:biosynthesis* / Q000235:genetics*; D014815:Vitamins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D014815:Vitamins; D005492:Folic Acid; D012256:Riboflavin