Prebiotic oligosaccharides and their fermentation products in a novel putative probiotic strain from the genus Weissella.

Sammanfattning: Our large intestine is like a large metabolic organ colonised by microorganisms. Beneficial probiotic bacteria are of interest since they might metabolise certain prebiotic carbohydrates and produce metabolites that are suggested to promote health and prevent diseases.   Strains of Weissella have proven probiotic properties since they, for example, show ability to metabolise prebiotic oligosaccharides, are resistant to a low pH (pH 2-3) and bile salt. In a previous project, six new strains of Weissella were isolated from Indian fermented food and vegetables, and four of them, including strain 92, were able to ferment xylooligosaccharides and form short chain fatty acids (SCFA), especially acetic acid. This strengthened the probiotic potential of these strains.   The aim of this project was to see if previously untested oligosaccharides (arabinooligosaccharides (AOS), laminarioligosaccharides (LOS) and chitooligosaccharides (COS)) could be metabolised by Weissella strain 92.   This study includes the following steps; cell growth in MRS (De Man, Rogosa and Sharpe) medium on different carbohydrates measured with spectrophotometer, pH measurement (analysing the difference of MRS medium (pH 6.42) pre and post cell growth, where reduced pH indicates acid production), and analysis of fermentation products (including SCFA (short chain fatty acids, e.g. acetic acid, butyric acid, propionic acid), lactic acid and ethanol) with an HPLC (high-performance liquid chromatography) instrument.   This research study has shown that Weissella strain 92 produces acetic and butyric acid as a consequence of use of AOS, LOS and COS, this indicates that the oligosaccharides are prebiotic and emphasizes the probiotic potential of Weissella strain 92.