Single Amino Acids as Sole Nitrogen Source for the Production of Lipids and Coenzyme Q by Thraustochytrium sp. RT2316-16

This work analyzes the production of total lipids and the content of CoQ₉ and CoQ₁₀ in the biomass of Thraustochytrium sp. RT2316-16 grown in media containing a single amino acid at a concentration of 1 g L⁻¹ as the sole nitrogen source; glucose (5 g L⁻¹) was used as the carbon source. Biomass concentration and the content of total lipids and CoQ were determined as a function of the incubation time; ten amino acids were evaluated. The final concentration of the total biomass was found to be between 2.2 ± 0.1 (aspartate) and 3.9 ± 0.1 g L⁻¹ (glutamate). The biomass grown in media containing glutamate, serine or phenylalanine reached a content of total lipids higher than 20% of the cell dry weight (DW) after 72, 60 and 72 h of incubation, respectively. The highest contents of CoQ₉ (39.0 ± 0.7 µg g⁻¹ DW) and CoQ₁₀ (167.4 ± 3.4 mg g⁻¹ DW) in the biomass of the thraustochytrid were obtained when glutamate and cysteine were used as the nitrogen source, respectively. Fatty acid oxidation, which decreased the total lipid content during the first 12 h of incubation, and the oxidation of hydrogen sulfide when cysteine was the nitrogen source, might be related to the content of CoQ₁₀ in the biomass of the thraustochytrid.