Binding of Fe(OH)3toLactobacillus delbrueckiissp.bulgaricusandLactobacillus acidophilus:  Apparent Role of Hydrogen Peroxide and Free Radicals

Kot, Eva; Furmanov, Sergey Mikhailovich; Bezkorovainy, Anatoly

doi:10.1021/jf9606058

Cited by 6 publications

(7 citation statements)

References 16 publications

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“…The oxidation of Fe 2+ to Fe 3+ in lactobacilli involves hydrogen peroxide produced by bacterial cells during aerobic incubation; this generates Fe(OH) 3 which binds the bacterial cell ( Kot et al . 1995b, 1996, 1997). Therefore, these micro‐organisms are extremely interesting for a ‘nutritional immunity’ phenomenon.…”

Section: Introductionmentioning

confidence: 99%

Iron requirement of Lactobacillus spp. in completely chemically defined growth media

Elli¹,

et al. 2000

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A completely chemically‐defined growth medium, containing guanine, thymine, cytidine, 2′‐deoxyadenosine and 2′‐deoxyuridine as DNA precursors, was developed for Lactobacillus johnsonii, on the basis of statistically designed techniques suitable for other lactobacilli. Particular focus was given to the nucleotide composition of different defined media, and to the specific nucleotide requirements of Lact. johnsonii. Most of the lactobacilli tested grew in a medium containing five free bases, four ribonucleosides or five deoxyribonucleosides. Adenine and guanine were replaceable by inosine. The requirement for thymine and cytosine was satisfied with uracil. The presence of inosine and uracil was identified as being essential for the growth of different Lactobacillus species, displaying their inability to synthesize purines and pyrimidines de novo. Defined recipes with different nucleotide composition were used to investigate iron requirements of lactobacilli. Only marginal differences in growth were observed in iron‐depleted media supplemented with five free bases, four ribonucleosides or five deoxyribonucleosides; iron depletion had a greater effect on growth when inosine and uracil were supplied as the only nucleotide sources. The results suggest that iron plays a role in the pyrimidine and purine metabolism of lactobacilli. Lactobacillus spp., particularly Lact. johnsonii, require iron under particular environmental conditions with limited or specific nucleotide sources.

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Section: Introductionmentioning

confidence: 99%

Iron requirement of Lactobacillus spp. in completely chemically defined growth media

Elli¹,

et al. 2000

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“…Analytical Procedures and Materials. Hydrogen peroxide was determined colorimetrically using Sigma kit 352 as previously described Kot et al, 1997). Lactate analysis was done using Sigma kit 826 UV as previously described .…”

Section: Methodsmentioning

confidence: 99%

Binding of Ferric Iron to the Cell Walls and Membranes ofBifidobacterium thermophilum: Effect of Free Radicals

Kot

Bezkorovainy

1999

J. Agric. Food Chem.

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Bifidobacterium thermophilum (ATCC 25866) was incubated with 100-120 microM (59)FeSO(4) and 300 microM excess of H(2)O(2) for up to 120 min in the presence and absence of glucose. Samples were withdrawn after 5, 30, 60, and 120 min. These were protoplasted and (59)Fe(III) measured in the supernatant fraction (cell walls) and protoplasts (cell membranes). These experiments were also repeated in the presence of 400 microM Al(III), which, in whole cells, caused an increase in Fe(III) binding. The amount of iron in the cell wall fraction was constant regardless of time of incubation, was unaffected by Al(III), and was reduced by approximately 20% by glucose. On the other hand, the amount of iron on the protoplasts increased with time and was affected by both Al(III) (upward) and glucose (downward). Scatchard plots indicated that the number of Fe(III) binding sites on the cell walls was 37.6 nmol/mg of dry cell weight at zero time, whereas that of cell membranes was (1)/(10) of that. It was concluded that Fe(III) binding by bifidobacterial cell walls was instantaneous and marginally dependent on free radical action. That of the cell membranes was time-dependent and was due to lipid peroxidation initiated by free radicals. Bifidobacteria can therefore function in the intestinal tract as probiotics by making Fe(OH)(3) unavailable to pathogens and by moderating free radical activity in the intestinal tract.

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“…Ferric Hydroxide Solutions and Binding. Ferric hydroxide solutions (more likely, colloidal suspensions) were prepared as previously described (Kot et al, 1997). Excess hydrogen peroxide content of stock Fe(OH) 3 solutions was decreased to undetectable levels by titrating 300 µM H2O2 with 10 mM FeSO4.…”

Section: Microorganismmentioning

confidence: 99%

“…bulgaricus, with which bifidobacteria may coexist in various food products, such as yogurts. L. bulgaricus can produce rather large quantities of hydrogen peroxide when glucose or another fermentable sugar is present in the medium (Kot et al, 1996(Kot et al, , 1997.…”

Section: Introductionmentioning

confidence: 99%

“…Our laboratory has investigated the effects of H 2 O 2iron-generated free radicals on the surface properties of both L. acidophilus and L. bulgaricus by examining the binding of ferric hydroxide to the free radicaldamaged bacterial surfaces (Kot et al, 1997). The action of free radicals was associated with an increased level of Fe(OH) 3 binding by the bacteria; the most likely reason for such surface alteration was peroxidation of the cell membrane lipid or another structure of cell membranes or cell walls.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Hydrogen Peroxide on the Physiology of Bifidobacterium thermophilum

Kot

Bezkorovainy

1998

J. Agric. Food Chem.

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Hydrogen peroxide was used as a source of OH-free radicals to study their effects on the physiology of Bifidobacterium thermophilum (ATCC 25866). H2O2 reduced the production of lactate in the absence of iron at [H2O2] = 250−855 μM; however, lactate production could be fully restored in these cells when they were freed of H2O2. Several potential free radical scavengers were not able to abate the effect of H2O2 on lactate production. Fe(OH)3 binding by the cells, which was used to detect cellular surface damage, was not affected by [H2O2] of up to 830 μM in the absence of exogenous iron. Growth of bifidobacteria could be reduced by [H2O2] as low as 41 μM, but growth resumed as the H2O2 disappeared from the medium. At high initial H2O2 concentrations (600 μM), at which no growth was observed for as long as 48 h, the cells remained viable and resumed growth in the absence of H2O2. It was concluded that H2O2 was bacteriostatic with respect to B. thermophilum at H2O2 concentrations used in this study, but whether this applies to other bifidobacterial species and strains must be determined by further research. Keywords: Bifidobacteria; hydrogen peroxide; free radicals; probiotics

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Binding of Fe(OH)₃toLactobacillus delbrueckiissp.bulgaricusandLactobacillus acidophilus: Apparent Role of Hydrogen Peroxide and Free Radicals

Cited by 6 publications

References 16 publications

Iron requirement of Lactobacillus spp. in completely chemically defined growth media

Iron requirement of Lactobacillus spp. in completely chemically defined growth media

Binding of Ferric Iron to the Cell Walls and Membranes ofBifidobacterium thermophilum: Effect of Free Radicals

Effect of Hydrogen Peroxide on the Physiology of Bifidobacterium thermophilum

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