title: Global Analysis of Mannitol 2-Dehydrogenase in Lactobacillus reuteri CRL 1101 during Mannitol Production through Enzymatic, Genetic and Proteomic Approaches.
abstract: Several plants, fungi, algae, and certain bacteria produce mannitol, a polyol derived from fructose. Mannitol has multiple industrial applications in the food, pharmaceutical, and medical industries, being mainly used as a non-metabolizable sweetener in foods. Many heterofermentative lactic acid bacteria synthesize mannitol when an alternative electron acceptor such as fructose is present in the medium. In previous work, we reported the ability of Lactobacillus reuteri CRL 1101 to efficiently produce mannitol from sugarcane molasses as carbon source at constant pH of 5.0; the activity of the enzyme mannitol 2-dehydrogenase (MDH) responsible for the fructose conversion into mannitol being highest during the log cell growth phase. Here, a detailed assessment of the MDH activity and relative expression of the mdh gene during the growth of L. reuteri CRL 1101 in the presence of fructose is presented. It was observed that MDH was markedly induced by the presence of fructose. A direct correlation between the maximum MDH enzyme activity and a high level of mdh transcript expression during the log-phase of cells grown in a fructose-containing chemically defined medium was detected. Furthermore, two proteomic approaches (2DE and shotgun proteomics) applied in this study confirmed the inducible expression of MDH in L. reuteri. A global study of the effect of fructose on activity, mdh gene, and protein expressions of MDH in L. reuteri is thus for the first time presented. This work represents a deep insight into the polyol formation by a Lactobacillus strain with biotechnological potential in the nutraceutics and pharmaceutical areas.
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Maria Eugenia
authors.initials: ME
authors.lastname: Ortiz
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Juliana
authors.initials: J
authors.lastname: Bleckwedel
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Silvina
authors.initials: S
authors.lastname: Fadda
authors.affiliation: Istituto di Scienze dell' Alimentazione-CNR, Avellino, Avellino, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Picariello
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Elvira M
authors.initials: EM
authors.lastname: Hebert
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Raúl R
authors.initials: RR
authors.lastname: Raya
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA)-CONICET, Chacabuco 145, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Fernanda
authors.identifier: http://orcid.org/0000-0002-2661-7661
authors.initials: F
authors.lastname: Mozzi
mesh_terms: D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000737:chemistry; D004789:Enzyme Activation; D005632:Fructose / Q000378:metabolism; D023281:Genomics / Q000379:methods; D052200:Limosilactobacillus reuteri / Q000235:genetics* / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism*; D008354:Mannitol Dehydrogenases / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002241:Carbohydrates; D005632:Fructose; D008353:Mannitol; D008354:Mannitol Dehydrogenases