title: Lactobacillus reuteri CRL1098 produces cobalamin.
abstract: We found that Lactobacillus reuteri CRL1098, a lactic acid bacterium isolated from sourdough, is able to produce cobalamin. The sugar-glycerol cofermentation in vitamin B(12)-free medium showed that this strain was able to reduce glycerol through a well-known cobalamin-dependent reaction with the formation of 1,3-propanediol as a final product. The cell extract of L. reuteri corrected the coenzyme B12 requirement of Lactobacillus delbrueckii subsp. lactis ATCC 7830 and allowed the growth of Salmonella enterica serovar Typhimurium (metE cbiB) and Escherichia coli (metE) in minimal medium. Preliminary genetic studies of cobalamin biosynthesis genes from L. reuteri allowed the identification of cob genes which encode the CobA, CbiJ, and CbiK enzymes involved in the cobalamin pathway. The cobamide produced by L. reuteri, isolated in its cyanide form by using reverse-phase high-pressure liquid chromatography, showed a UV-visible spectrum identical to that of standard cyanocobalamin (vitamin B12).
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA-CONICET) Instituto de Microbiología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Tucumán, Argentina.
authors.forename: María P
authors.initials: MP
authors.lastname: Taranto
authors.forename: José L
authors.initials: JL
authors.lastname: Vera
authors.forename: Jeroen
authors.initials: J
authors.lastname: Hugenholtz
authors.forename: Graciela F
authors.initials: GF
authors.lastname: De Valdez
authors.forename: Fernando
authors.initials: F
authors.lastname: Sesma
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins; D050260:Carbohydrate Metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003486:Cyanides / Q000737:chemistry; D005285:Fermentation; D005798:Genes, Bacterial; D005990:Glycerol / Q000378:metabolism; D007778:Lactobacillus / Q000235:genetics / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D014805:Vitamin B 12 / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D003486:Cyanides; D019883:Alkyl and Aryl Transferases; C082269:ATP-corrinoid adenosyltransferase; D014805:Vitamin B 12; D005990:Glycerol