Investigation of new exopolysaccharides produced by strains of donkey milk

Arevik Israyelyan; Tsovinar Balabekyan; Lara Aleksanyan; Inesa Sahakyan; Anna Gasparyan; Flora Тkhrun

doi:10.18502/ijm.v17i1.17808

Arevik Israyelyan Scientific and Production Center “Armbiotechnology” NSPO, National Academy of Science, Probiotics Production Sector, Yerevan, Republic of Armenia
Tsovinar Balabekyan Scientific and Production Center “Armbiotechnology” NSPO, National Academy of Science, Probiotics Production Sector, Yerevan, Republic of Armenia
Lara Aleksanyan Scientific and Production Center “Armbiotechnology” NSPO, National Academy of Science, Probiotics Production Sector, Yerevan, Republic of Armenia
Inesa Sahakyan Department Histochemistry and Functional Morphology, Buniatyan Institute of Biochemistry National Academy of Science, Yerevan, Republic of Armenia
Anna Gasparyan Scientific and Production Center “Armbiotechnology” NSPO, National Academy of Science, Probiotics Production Sector, Yerevan, Republic of Armenia
Flora Тkhrun Scientific and Production Center “Armbiotechnology” NSPO, National Academy of Science, Probiotics Production Sector, Yerevan, Republic of Armenia

DOI: https://doi.org/10.18502/ijm.v17i1.17808

Keywords: Exopolysaccharides; Protein-like fractions; Interaction; Donkey milk; Antimicrobial activity

Abstract

Background and Objectives: It has been shown that strains of the genus Enterococcus isolated from donkey milk from different regions of the Republic of Armenia have antimicrobial activity, synthesize different polysaccharides and produce disaccharide polymers (glucose and galactose). The quantitative synthesis of polysaccharides (8-15%) depends on the com- position of the nutrient medium, temperature and growing time.

Materials and Methods:Species identification of LAB strains was confirmed by 16S rDNA gene sequencing method using universal primers LAB strains. The methods used for extraction, purification and detection of exopolysaccharides are based on the method of Sørensen et al. (2022). The antibacterial activity of EPS was investigated by agar diffusion assay. Determi- nation of the immunostimulating property was carried out using the ELISA method.

Results: The antimicrobial activity of the polysaccharide and antimicrobial protein-like fractions of the genus Enterococcus strains depends on its concentration, time of interaction with the test culture, and the species of the pathogenic bacteria.

Conclusion: The obtained results were shown that strains isolated from fermented donkey milk that are capable of synthesiz- ing two substances of different nature with high antimicrobial properties during the growth process are promising for further research and application for their use as probiotics and biopreparations in pharmaceuticals.