Czech Journal of Food Sciences (Oct 2004)

biosynthesis of folates by lactic acid bacteria and propionibacteria in fermented milk

  • M. Holasová,
  • V. Fiedlerová,
  • P. Roubal,
  • M. Pechačová

DOI
https://doi.org/10.17221/3421-CJFS
Journal volume & issue
Vol. 22, no. 5
pp. 175 – 181

Abstract

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Folate producing ability of several strains of Bifidobacterium longum, Bifidobacterium bifidum, Streptococcus thermophilus and Propionibacterium freudenreichii subsp. shermanii was evaluated. As substrate, UHT milk with 1.5% fat content treated with additional laboratory sterilisation was used. Fermentation was conducted at 37°C and 30°C in the case of Propionibacterium. 5-Methyltetrahydrofolate (5-MTHF) concentrations were determined using HPLC method. All strains of Streptococcus thermophilus tested showed 5-MTHF production. More than six-fold increase was found in the 5-MTHF content in comparison with control (increase = 3.69 µg 5-MTHF/100 g) after 12 h fermentation. Bifidobacterium longum strains were recognised as mild folate producers with max. 73% increase in the 5-MTHF content (increase = 0.48 µg 5-MTHF/100 g) after 12 h fermentation. The Propionibacterium freudenreichii subsp. shermanii strains tested did not basically influence the 5-MTHF levels during milk fermentation. In all cases, maximum 5-MTHF concentration was reached between 6 and 12 hours of fermentation. Large differences in the 5-MTHF production were found among individual strains within species. By a careful testing of the folate production ability of microbial strains used in the production of fermented milk, an enhancement of the natural folate content can be achieved.

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