Biosynthesis of polyunsaturated fatty acids by two newly cold-adapted Egyptian marine yeast

The widespread awareness of polyunsaturated fatty acids (PUFAs) benefits for human health has increased the need for their commercial production. Two oleaginous yeast were isolated from the Mediterranean Sea fish and Red Sea fish Epinephelus aeneus and E. areolatus, respectively. These marine candidates were identified by MALDI-TOF/MS biotyper^® as Lodderomyces elongisporus and Rhodotorula mucilaginosa. The effect of incubation temperature (7, 15, and 26 °C) and glucose concentration (3% and 8%) on their lipids content were investigated using Sulfo-Phospho-Vanillin (SPV) assay. Their intercellular lipids were visualized by fluorescence microscope using Nile-Red dye. L. elongisporus and R. mucilaginosa produced 20.04% and 26.79% of Linoleic acid, respectively, on normal Basal-Defatted Medium (BDM). Linoleic acid (21.4-22.7%) and α-Linolenic acid (7.5-10.8%) were produced by R. mucilaginosa and L. elongisporus, on normal BDM at 15 °C. High-Glucose BDM induced a positive effect on the total lipids production that reached its maximum of 48% and 54% by R. mucilaginosa and L. elongisporus, respectively, grown at 15 °C. Remarkably, 12.12% of long-chain 15-Docosenoic acid (C_22:1) and 21.49% of Tricosanoic acid (C_23:0) were detected in the FAs profile of L. elongisporus, when grown on normal BDM at 26 °C. The present study is the first one reporting the FAs profile of the Egyptian Marine L. elongisporus, and its capability to accumulate high amounts of lipids under appropriate fermentation conditions; thus, it could be considered for scaling up production.

The online version contains supplementary material available at 10.1007/s13205-021-03010-4.