Molecular Identification of Yeast Strains in Dried Flowers of Woodfordia fruticosa

Abstract

Dried flowers of Woodfordia fruticosa (Sinhala: Malitha) are used in the preparation of Arishta. It has been recorded that these flowers facilitate the fermentation process of Arishta. The main objective of the present study was to identify the yeast strains contained in dry W. fruticosa flowers. These yeast strains are not only responsible for the fermentation but also in biotransformation processes. However, yeast strains contained in dry W. fruticosa flowers have not yet been identified at the molecular level. In the present study we used dry W fruticosa flowers imported from India available in the open market. In total 33 yeast strains were isolated from W. fruticosa flowers and colony characters of all isolated yeast lines found to be similar. The molecular identification of yeast species was carried out by using RAPD-M13 PCR profiles and analysis of amplified ITS1-5.8S-ITS2 region of these yeast lines. Saccharomyces cerevisiae, a type strain, was used to determine whether S. cerevisiae is present or not. According to the results of ITS region analysis, the yeast strains isolated from dry W. fruticosa flowers were not S. cerevisiae. The species level identification of one of these yeast strains was carried out by sequencing of ITS1-5.8S-ITS2 region and comparison with the sequences in NCBI database. According to the sequence analysis the yeast strains in dry W. fruticosa flowers were identified as Candida tropicalis.