Intraspecific variations in macronutrient, amino acid, and fatty acid composition of mass-cultured Teleaulax amphioxeia (Cryptophyceae) strains

To compare the nutritional quality of TPG (Teleaulax / Plagioselmis / Geminigera) clade species of cryptomonads with that of RHO (Rhodomonas / Rhinomonas / Storeatula) clade species 6 Teleaulax amphioxeia (TA) and 1 Rhinomonas sp. strains were mass-cultured in newly designed 500-L photobioreactors to the end of exponential growth phase. Intraspecific variations (IVs) in terms of one standard deviation among the 6 TA strains in the compositions of the three macronutrients were 41.5 (protein), 89.8 (lipid), and 15.6% (carbohydrate) of the mean. When harvested from stationary growth phase mean compositions of essential amino acids (EAAs, 47.3%) and non-EAAs (52.7%) of the 2 TA strains, CR-MAL07 and CR-MAL08-2, were similar to those of a Chroomonas strain. The IVs between the 2 TA strains in the composition of EAAs (10.3 and 2.4) and non-EAAs (8.5 and 2.1% of the mean) were rather smaller than those of saturated fatty acids (30.3 and 26.1) and unsaturated fatty acids (UFAs, 12.0 and 12.5% of the mean) in f/2-Si and urea-based compound fertilizer (UCF) culture media, respectively. Mean compositions of eicosapentaenoic acid (EPA, 17.9%) and docosahexaenoic acid (DHA, 12.7%) of total fatty acids of the 2 TA strains were higher than those that of a Chroomonas strain. EPA and DHA compositions exhibited similar level of IVs between the 2 TA strains in f/2-Si (14.6 and 11.0) and UCF media (12.6 and 13.5% of the mean). Thus, the nutritional quality in terms of amino acids, UFAs, EPA, and DHA in a TPG clade species, T. amphioxeia was comparable to those of RHO clade species with notable IVs. Practically, biotechnological targets for TPG clade cryptomonad strains might be subspecies or clone level.