Molecular screening of astaxanthin-producing yeasts of birch sap-flows in Alborz Province of Iran

The carotenoid-producing yeasts have a widespread distribiution  worldwide. However, isolation of carotenoid-producing yeasts with valuable astaxanthin have been only reported from limited areas and specific habitats. The aim of this study was to apply the multiple polymerase chain reaction method for faster molecular screening of isolates for the yeasts in the exudation sap from birch trees (Betula pendula Roth.) in Alborz Province of Iran with astaxanthin production capacity and toevaluate its efficiency.

This cross-sectional study was carried out by sampling in May 2018 from one of the natural habitats of birch trees Batula Pendula in Alborz Province, Iran. After isolation of yeasts using selected media and purification of yeast colonies with various pink to red colors, yeasts genomic nucleic acids were extracted and molecular screening for astaxanthin-producing detection of isolates was performed by multiple polymerase chain reaction (Multiplex-PCR).

Out of 42 pigmented colonies during sampling and isolation in one cross-sectional study, 23 pink to red colonies were evaluated by Multiplex-PCR method. Of these isolates, three were positive and the rest were negative. The results were validated by determining the ribosomal gene sequencing.

The present study demonstrates the specificity of the multiple polymerase chain     reaction method in fast and cost-effective molecular screening of astaxanthin-producing yeast   isolates and the applicability of this method to study other natural habitats of these yeasts.