Thraustochytrids from the Red Sea mangroves in Egypt and their abilities to produce Omega-3 fatty acids

Abstract Forty-one isolates of the genus Aurantiochytrium were cultured from 32 samples collected from the Red Sea mangroves, Egypt. Cultured thraustochytrids isolated from: decaying leaves of Avicennia marina (34 isolates), decaying pneumatophores of A . marina (3 isolates), and decaying leaves of Zostera marina (4 isolates). Of the 41 strains, three strains (SUMCC 21014, SUMCC 21015, and SUMCC 21016) were selected based on both their high biomass production and high lipid content. Phylogenetic analyses based on 18 S rDNA placed the three strains within the Aurantiochytrium clade with high statistical support. The three strains were cultured on GYP broth (glucose, yeast extract, peptone) and exhibited different dry cell weights and lipid contents. Lipid profiles were determined using GC-FID analysis. Among the three studied strains, SUMCC 21016 produced the highest biomass of 2.04 g/L, the highest lipid content (0.991 g/L), and a good docosahexaenoic acid percentage (0.217 g/L). Among the three studied strains, SUMCC 21014 produced the highest percentages of DHA (30.3%) and EPA (5.45%) of the total fatty acids but its dry weight is lower than SUMCC 21016.