Free radical formation by Lactobacillus acidophilus NCFM is enhanced by antioxidants and decreased by catalase

TY - JOUR

T1 - Free radical formation by Lactobacillus acidophilus NCFM is enhanced by antioxidants and decreased by catalase

AU - Hougaard, Anni Bygvrå

AU - Kristensen, Helene Pindstrup

AU - Arneborg, Nils

AU - Andersen, Mogens Larsen

AU - Skibsted, Leif Horsfelt

PY - 2016/1/1

Y1 - 2016/1/1

N2 - Lactobacillus acidophilus NCFM was found to increase the production of transient radicals during growth in a 1:1 mixture of brain heart infusion broth and de Man-Rogosa-Sharpe broth as detected by electron spin resonance (ESR) spectroscopy using spin trapping. During growth of L. acidophilus NCFM addition of quercetin, rutin or a whey protein hydrolysate, normally all with antioxidant activity, further increased formation of transient radicals. Such increase in the level of radicals in the growth medium did not have an adverse effect on the viability of L. acidophilus NCFM, but may be involved in inhibition of pathogenic bacteria by L. acidophilus. Catalase decreased the production of radicals without effect on the growth of the catalase-negative L. acidophilus NCFM, whereas superoxide dismutase had no effect on radical production, but hampered bacterial growth. The effect of catalase may be explained by non-radical removal of hydrogen peroxide otherwise being a precursor for hydroxyl radicals formed by transition metal catalysis. Metal ion concentrations decreased in the medium during bacterial growth, which may be the result of transport across bacterial membranes of redox active metal ions like iron and copper chelated by the antioxidant competing with reductive cleavage of hydrogen peroxide forming hydroxyl radicals. Antioxidants may accordingly promote probiotic effect of catalase-negative bacteria through increased formation of reactive oxygen species.

AB - Lactobacillus acidophilus NCFM was found to increase the production of transient radicals during growth in a 1:1 mixture of brain heart infusion broth and de Man-Rogosa-Sharpe broth as detected by electron spin resonance (ESR) spectroscopy using spin trapping. During growth of L. acidophilus NCFM addition of quercetin, rutin or a whey protein hydrolysate, normally all with antioxidant activity, further increased formation of transient radicals. Such increase in the level of radicals in the growth medium did not have an adverse effect on the viability of L. acidophilus NCFM, but may be involved in inhibition of pathogenic bacteria by L. acidophilus. Catalase decreased the production of radicals without effect on the growth of the catalase-negative L. acidophilus NCFM, whereas superoxide dismutase had no effect on radical production, but hampered bacterial growth. The effect of catalase may be explained by non-radical removal of hydrogen peroxide otherwise being a precursor for hydroxyl radicals formed by transition metal catalysis. Metal ion concentrations decreased in the medium during bacterial growth, which may be the result of transport across bacterial membranes of redox active metal ions like iron and copper chelated by the antioxidant competing with reductive cleavage of hydrogen peroxide forming hydroxyl radicals. Antioxidants may accordingly promote probiotic effect of catalase-negative bacteria through increased formation of reactive oxygen species.

U2 - 10.1016/j.foodres.2015.12.003

DO - 10.1016/j.foodres.2015.12.003

M3 - Journal article

SN - 0963-9969

VL - 79

SP - 81

EP - 87

JO - Food Research International

JF - Food Research International

ER -