Lactococcus lactis SpOx spontaneous mutants: a family of oxidative-stress-resistant dairy strains.
Numerous industrial bacteria generate hydrogen peroxide (H(2)O(2)), which may inhibit the growth of other bacteria in mixed ecosystems. We isolated spontaneous oxidative-stress-resistant (SpOx) Lactococcus lactis mutants by using a natural selection method with milk-adapted strains on dairy culture medium containing H(2)O(2). Three SpOx mutants displayed greater H(2)O(2) resistance. One of them, SpOx3, demonstrated better behavior in different oxidative-stress situations: (i) higher long-term survival upon aeration in LM17 and milk and (ii) the ability to grow with H(2)O(2)-producing Lactobacillus delbrueckii subsp. delbrueckii strains. Furthermore, the transit kinetics of the SpOx3 mutant in the digestive tract of a human flora-associated mouse model was not affected.
Rochat
Tatiana
T
Unité de Recherches Laitières et de Génetique, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France.
Gratadoux
Jean-Jacques
JJ
Corthier
Gérard
G
Coqueran
Bérard
B
Nader-Macias
Maria-Elena
ME
Gruss
Alexandra
A
Langella
Philippe
P
D000818:Animals; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D013294:Lactococcus lactis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D051379:Mice; D008892:Milk / Q000382:microbiology; D009154:Mutation; D018384:Oxidative Stress
D006861:Hydrogen Peroxide