Antimicrobial activity of broth fermented with kefir grains

Appl Biochem Biotechnol. 2009 Feb;152(2):316-25. doi: 10.1007/s12010-008-8303-3. Epub 2008 Jul 29.


Kefir grains originate from the Caucasus region and are used for preparing beverages using sugar solution, milk, and fruit juice. As long as they are formed by a microbial consortium useful in the intestine, the produced drinks can be called probiotics. The aim of this study was to determine the antimicrobial activity during kefir fermentation in sugar broth. Fermentations with three kinds of carbohydrates (molasses, demerara sugar, and brown sugar) as carbon source were carried out. Brown sugar promoted the greatest antimicrobial activities, producing inhibition halos corresponding to 35, 14, 12, 14, and 14 mm for Candida albicans, Salmonella typhi, Shigella sonnei, Staphylococcus aureus, and Escherichia coli, respectively. Different carbon source concentrations and the time of fermentation influenced the size of the inhibition halos of the pathogenic microorganisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / metabolism*
  • Anti-Infective Agents / pharmacology*
  • Bacteria / drug effects
  • Candidiasis, Oral / microbiology
  • Culture Media / chemistry*
  • Cultured Milk Products / metabolism*
  • Fermentation*
  • Fungi / drug effects
  • Gastrointestinal Diseases / microbiology
  • Hydrogen-Ion Concentration
  • Molasses
  • Time Factors


  • Anti-Infective Agents
  • Culture Media