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Extended Abstract

Isolation and Characterization of Kefiran Exopolysaccharides from Romanian Kefir Grains †

National Institute of Research and Development for Biological Sciences-INCDSB, 296 Spl. Independenței, 060031 Bucharest, Romania
National Institute of Research and Development for Food Bioresources-IBA, Street Ancuța Băneasa 5, 020323 Bucharest, Romania
Author to whom correspondence should be addressed.
Presented at the 15th International Symposium “Priorities of Chemistry for a Sustainable Development” PRIOCHEM, Bucharest, Romania, 30th October–1st November 2019.
Proceedings 2019, 29(1), 125;
Published: 22 October 2019
(This article belongs to the Proceedings of Priorities of Chemistry for a Sustainable Development-PRIOCHEM)
Kefiran is the water-soluble branched glucogalactan from kefir grains and it contains D-galactose and D-glucose units in approximately equal quantities [1]. These bacterial exopolysaccharides, because of their status as probiotics for the bacteria that generated them, will become a category of biopolymers that offer new perspectives in the development of products with health and safety benefits [2]. The aim of our study was to obtain kefiran from a Romanian kefir artisanal culture and to characterize it physicochemically and biologically, in order to evaluate its potential as a nutraceutical.
The extraction of kefiran was performed by alcohol precipitation and the evaluation of the total carbohydrates and hexoses content was done by spectrophotometric methods, while the major carbohydrates were identified by 1H-NMR, and glucose and galactose were quantified by HPLC methods. Structural observations on kefiran extract were performed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cytotoxicity and anti-tumoral activity were tested with normal fibroblasts (NCTC clone L929) and epithelial tumoral (HT-29) cell cultures, cultivated in the presence of kefiran, in standard conditions, for 24 and 72 h.
Structural analyses revealed that the kefiran is composed of a hexasaccharide repeating unit, sugar composition analysis confirmed the previously reported values [3]. Ultrastructural and morphological analysis showed a fibrillar structure of kefiran (by TEM) and a compact structure with a homogenous matrix and smooth surface (by SEM), specific to polymeric materials. In the presence of kefiran concentrations ranging from 50 to 2700 mg/L, an antitumoral effect was observed at 72 h, while the cytotoxic effect was registered for concentrations that exceeded 500 mg/L.
These results demonstrated that kefiran extract presented valuable properties and confirmed its potential use in nutraceutical and biological applications.


This work was supported by a grant of the Romanian Ministry of Research and Innovation, CCCDI-UEFISCDI, project no. PN-III-P3-3.5-EUK-2017-02-0026, contract no. 62/2018.


  1. Wang, Y.; Ahmed, Z.; Feng, W.; Li, C.; Song, S. Physicochemical properties of exopolysaccharide produced by Lactobacillus kefiranofaciens ZW3 isolated from Tibet kefir. Int. J. Biol. Macromol. 2008, 43, 283–288. [Google Scholar] [CrossRef] [PubMed]
  2. Badel, S.; Bernardi, T.; Michaud, P. New perspectives for Lactobacilli exopolysaccharides. Biotechnol. Adv. 2011, 29, 54–66. [Google Scholar] [CrossRef] [PubMed]
  3. Micheli, L.; Uccelletti, D.; Palleschi, C.; Crescenzi, V. Isolation and characterisation of a ropy Lactobacillus strain producing the exopolysaccharide kefiran. Appl. Microbiol. Biot. 1999, 56, 69–76. [Google Scholar] [CrossRef] [PubMed]
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MDPI and ACS Style

Uţoiu, E.; Iosăgeanu, A.; Toma, A.; Mănoiu, S.; Uţoiu, C.; Oancea, A. Isolation and Characterization of Kefiran Exopolysaccharides from Romanian Kefir Grains. Proceedings 2019, 29, 125.

AMA Style

Uţoiu E, Iosăgeanu A, Toma A, Mănoiu S, Uţoiu C, Oancea A. Isolation and Characterization of Kefiran Exopolysaccharides from Romanian Kefir Grains. Proceedings. 2019; 29(1):125.

Chicago/Turabian Style

Uţoiu, Elena, Andreea Iosăgeanu, Agnes Toma, Sorin Mănoiu, Claudiu Uţoiu, and Anca Oancea. 2019. "Isolation and Characterization of Kefiran Exopolysaccharides from Romanian Kefir Grains" Proceedings 29, no. 1: 125.

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