Isolation and Molecular Identification of Yeasts in Different Food Stuff and Determine Their Abilities for Phenols and Flavonoids Productivity by HPLC Analysis

Abstract

This investigation was isolated forty-three spoilage yeasts from twelve different spoilage food sources included (guava, tomato, strawberry, pickled carrot, orange juice, grape, date, cheese, potato, okra, onion and dough) by used three kinds of media (PDA, MYEA and MEA) and three isolation techniques (touch, direct and dilution plate methods). The result recorded that the guava represent the richest sources with 15 yeasts isolated. The MYEA medium represented the most suitable medium for isolation of yeast from these sources and recorded 35 yeasts isolates, and also the result show that 28 yeasts isolates were isolated by direct plate method which represented the most suitable techniques for yeast isolation from the previous sources. The isolated yeast was classified according to their colony colors into four categories includes white, off-white, creamy and red colors. The total numbers of isolated yeast and its kinds are affected by the source, techniques, and media used in isolations. The ability of all isolated yeasts was screened for phenol and flavonoid productivity. The highest productive phenol and flavonoid yeasts were selected for identifying by molecular techniques, performed by phenotypic characteristics and ITS region. Also, those highest phenols and flavonoid producers strains were confirmed their productivity by using HPLC analysis.