Isolation and evaluation of probiotic properties of bacteria isolated from the medicinal plants of the Asteraceae family of Tehran and Karaj regions

BACKGROUND AND OBJECTIVESProbiotics are beneficial live microorganisms that promote host health when consumed in sufficient quantities. Medicinal plants, particularly those belonging to the Asteraceae or Compositae family, are a potential source for isolating probiotic bacteria. In addition, the rhizosphere, the ecological niche surrounding plant roots, is an important area for identifying probiotics due to the competition between resident microorganisms for growth factors.MATERIALS AND METHODSA total of ۲۰۴ Gram-positive bacteria strains were isolated from the aerial parts and soil surrounding the rhizosphere of genera belonging to Achillea, Artemisia, Cichorieae, Echinops, Onopordum, Centaurea, Gundelia, Carduus, Jurinea, Tanacetum, Cichorium, Echinacea, and Grindelia. These strains were cultured on MRS and TSA. In vitro assessments were conducted to determine the probiotic potential of the isolated bacteria, including hemolytic activity, resistance to gastric acid, resistance to bile salts, and resistance to pepsin and trypsin enzymes. Finally, ۱۶S rRNA analysis was performed using primers ۲۷ F and ۱۴۹۲ R for identification.RESULTS AND DISCUSSIONBased on the tests, a strain isolated on TSA medium from the rhizosphere soil of Tanacetum vulgare was subjected to molecular analysis and identified as Bacillus licheniformis through BLAST analysis. The strain exhibited characteristics such as non-hemolytic activity, ability to survive at pH ۲.۵ and ۴, growth in a medium containing ۰.۳% bile salt, and growth in media containing ۰.۲% pepsin and trypsin.CONCLUSION Medicinal plants and rhizosphere soil are among the resources that have been less considered for the isolation of probiotic bacteria. Therefore, the investigation, isolation, and identification of probiotic strains from the Asteraceae family have great importance in various industries.

کلیدواژه ها:

Probiotic bacteria ، Bacillus ، Medicinal plants ، rhizosphere soil ، Asteraceae