In: Sydowia 76, (2024): 201-212; ISSN 0082-0598, DOI 10.12905/0380.sydowia76-2024-0201, Published online on May 06, 2024

Molecular characterization of marine yeasts isolated from the Red Sea coast of Saudi Arabia

Ahmed E. Al-Sabri* & Mansour K. Gatasheh

1 Department of Botany and Microbiology, College of Sciences, King Saud University, P.O. Box 2455, Riyadh 11451,
Saudi Arabia
2 Department of Biochemistry, College of Sciences, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia

* e-mail: aalsabri@ksu.edu.sa

Al-Sabri A.E. & Gatasheh M. K. (2024) Molecular characterization of marine yeasts isolated from the Red Sea coast of Saudi
Arabia. – Sydowia 76: 201–212.

Marine yeasts are a diverse group of eukaryotic microorganisms that play important roles in marine ecosystems. Little is
known about the biodiversity of marine yeasts from the Red Sea. The occurrence of cultivable yeasts was investigated along the
water column (0–10 meter depth) of six off-shore locations at two discrete sites in the Red Sea. An unexpectedly high abundance
of yeasts, accompanied by scarce biodiversity, was observed up to 10-meter depth. The yeast isolates belonged to the five genera:
Rhodotorula, Candida, Pichia, Cryptococcus, and Hortaea. Phylogenetic analyses based on 28S rRNA gene sequences allowed us
to establish the precise taxonomic position of each of the isolates and thereby investigate the intraspecific relationships among
them. Eight strains of black yeast were identified as members of Hortaea, which showed a wide distribution in the deep-sea, and
shallow areas. This is the first report on the isolation of marine yeasts from Red Sea water. The occurrence of Candida dubliniensis
is also being reported for the first time in marine environments.

Keywords: rRNA, microbiota, black yeasts, Candida dubliniensis, Al-Qunfudhah