Isolation, Characterization, and Identification of Yeasts Associated with Foods from Assiut City, Egypt
Sadat Mohammad Rezq Khattab *
Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Assiut, Branch, Assiut, 71524, Egypt.
Ahmed Mustafa Abdel-Hadi
Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Assiut, Branch, Assiut, 71524, Egypt and Department of Medical Laboratories, College of Applied Medical Sciences, Majmaah University, 11925, Kingdom of Saudi Arabia.
Nageh Fathy Abo-Dahab
Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Assiut, Branch, Assiut, 71524, Egypt.
Omar Mohammad Atta
Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Assiut, Branch, Assiut, 71524, Egypt.
*Author to whom correspondence should be addressed.
Abstract
The objective of this work was to isolate, characterize physiologically, and identify yeasts associated with foods from Assiut city, Egypt. Fifty-two colonies of yeasts associated with orange, mandarin, tomato, squash, sobia drink, mango juice, sugarcane juice, yogurt and buttermilk samples, collected from Assiut City, Egypt, were isolated. Out of which, Eleven isolates were selected randomly and subjected to morphological, biochemical studies and molecular identification techniques employing sequence of internal transcribed spacer (ITS) regions and partial D1/D2 large-subunit domains of the 26S ribosomal RNA. Identified yeasts were belonged to six genera and species; four species belonged to ascomycetes: Debaryomyces hansenii (five isolates), Saccharomyces cerevisiae (one isolate), Candida tropicalis (one isolate), and Pichia kudriavzevii (one isolate). In addition, two yeasts species belonged to basidiomyces: Rhodotorula mucilaginosa (two isolates), and Trichosporon dulcitum (one isolate). In spite of low frequency of yeasts isolates on the tested food, mango juice and buttermilk showed the higher sources for incidences during this study.
Keywords: Yeasts isolation, Identification, milk products, fruits, juices, Assiut City, Egypt