Identification of yeast strains in three different “Arishta” using molecular techniques

Abstract

In Sri Lanka“Arishta” is prepared from medicinal plant materials and it is well known as “Herbal wine”. Arishta isparticularly interesting because of its medicinal value. Dry Woodfordia Fruticosa flowers are used in order to provideyeast strains needed for fermentation and biotransformation processes in Arishta. However, yeast strains involved in preparation in local arishta have not been identified at the molecular level until this investigation. The Saccharomyces cerevisiae is the well known yeast species which is used in many industries. Therefore the main objective of the present study was to determine whether Saccharomyces cerevisiae is involved in fermentation in Arishta. Hence the identification of yeast strains present in Arishta was carried out during its fermentation process. In the present study three different Arishta was used i.e. Ashwagandha, Nimba and Dasamula. In total, 33 yeast isolates were isolated from three different Arishta and dry Woodfordia fruticosa flowers. The molecular identification of yeast species was carried out by RAPD-M13 PCR profiles and analysis of amplified ITS1-5.8S-ITS2 region of selected yeast lines. Saccharomyces cerevisiae, a type strain, was used to determine whether Saccharomyces cerevisiae is present in the fermentation process. According to results of ITS region analysis, the yeast strains isolated from Arishta were not Saccharomyces cerevisiae. Therefore, the species level identification of this yeast strain in Arishta was carried out by sequence of ITS1-5.8S-ITS2 region and comparison with the sequences in NCBI database. According to the sequence analysis the yeast strains in “Arishta” were identified as Candida Guilliermondii which is the vegetative stahe of pichia ohmeri.