Open AccessProduction of a Heterologous Nonheme Catalase by Lactobacillus casei : an Efficient Tool for Removal of H 2 O 2 and Protection of Lactobacillus bulgaricus from Oxidative Stress in Milk
Author(s) -
Tatiana Rochat,
Jean-Jacques Gratadoux,
Alexandra Gruss,
Gérard Corthier,
Emmanuelle Maguin,
Philippe Langella,
Maarten van de Guchte
Publication year - 2006
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.00482-06
Subject(s) - lactobacillus casei , lactococcus lactis , lactobacillus plantarum , lactobacillus , biology , microbiology and biotechnology , catalase , lactobacillaceae , heterologous expression , bacteria , lactococcus , heterologous , lactobacillus delbrueckii subsp. bulgaricus , lactic acid , probiotic , enzyme , food science , biochemistry , fermentation , gene , recombinant dna , genetics
Lactic acid bacteria (LAB) are generally sensitive to H2 O2 , a compound that they can paradoxically produce themselves, as is the case forLactobacillus bulgaricus. Lactobacillus plantarum ATCC 14431 is one of the very few LAB strains able to degrade H2 O2 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, andLactococcus lactis MG1363. While the protein could be detected in all heterologous hosts, enzyme activity was observed only inL. casei . This is probably due to the differences in the Mn contents of the cells, which are reportedly similar inL. plantarum andL. casei but at least 10- and 100-fold lower inLactococcus lactis andL. bulgaricus , respectively. The expression of the MnKat gene inL. casei conferred enhanced oxidative stress resistance, as measured by an increase in the survival rate after exposure to H2 O2 , and improved long-term survival in aerated cultures. In mixtures ofL. casei producing MnKat andL. bulgaricus ,L. casei can eliminate H2 O2 from the culture medium, thereby protecting bothL. casei andL. bulgaricus from its deleterious effects.