title: Production of a heterologous nonheme catalase by Lactobacillus casei: an efficient tool for removal of H2O2 and protection of Lactobacillus bulgaricus from oxidative stress in milk.
abstract: Lactic acid bacteria (LAB) are generally sensitive to H2O2, a compound that they can paradoxically produce themselves, as is the case for Lactobacillus bulgaricus. Lactobacillus plantarum ATCC 14431 is one of the very few LAB strains able to degrade H2O2 through the action of a nonheme, manganese-dependent catalase (hereafter called MnKat). The MnKat gene was expressed in three catalase-deficient LAB species: L. bulgaricus ATCC 11842, Lactobacillus casei BL23, and Lactococcus lactis MG1363. While the protein could be detected in all heterologous hosts, enzyme activity was observed only in L. casei. This is probably due to the differences in the Mn contents of the cells, which are reportedly similar in L. plantarum and L. casei but at least 10- and 100-fold lower in Lactococcus lactis and L. bulgaricus, respectively. The expression of the MnKat gene in L. casei conferred enhanced oxidative stress resistance, as measured by an increase in the survival rate after exposure to H2O2, and improved long-term survival in aerated cultures. In mixtures of L. casei producing MnKat and L. bulgaricus, L. casei can eliminate H2O2 from the culture medium, thereby protecting both L. casei and L. bulgaricus from its deleterious effects.
authors.affiliation: Unité d'Ecologie et de Physiologie du Système Digestif, INRA, Domaine de Vilvert, 78352 Jouy en Josas Cedex, France.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Rochat
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Gratadoux
authors.forename: Alexandra
authors.initials: A
authors.lastname: Gruss
authors.forename: Gérard
authors.initials: G
authors.lastname: Corthier
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Maguin
authors.forename: Philippe
authors.initials: P
authors.lastname: Langella
authors.forename: Maarten
authors.initials: M
authors.lastname: van de Guchte
mesh_terms: D000818:Animals; D002374:Catalase / Q000235:genetics* / Q000378:metabolism*; D003470:Culture Media; D005285:Fermentation; D005516:Food Microbiology; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007778:Lactobacillus / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D007780:Lacticaseibacillus casei / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008345:Manganese / Q000378:metabolism; D008892:Milk / Q000382:microbiology*; D018384:Oxidative Stress; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins; D008345:Manganese; D006861:Hydrogen Peroxide; D002374:Catalase