Fatty acid and metabolomic profiling approaches differentiate heterotrophic and mixotrophic culture conditions in a microalgal food supplement 'Euglena'

Min Zeng, Wenlong Hao, Yongdong Zou, Mengliang Shi, Yongguang Jiang, Peng Xiao, Anping Lei, Zhangli Hu, Weiwen Zhang, Liqing Zhao, Jiangxin Wang

Microalgae have been recognized as a good food source of natural biologically active ingredients. Among them, the green microalga Euglena is a very promising food and nutritional supplements, providing high value-added poly-unsaturated fatty acids, paramylon and proteins. Different culture conditions could affect the chemical composition and food quality of microalgal cells. However, little information is available for distinguishing the different cellular changes especially the active ingredients including poly-saturated fatty acids and other metabolites under different culture conditions, such as light and dark. In this study, together with fatty acid profiling, we applied a gas chromatography-mass spectrometry (GC-MS)-based metabolomics to differentiate hetrotrophic and mixotrophic culture conditions. This study suggests metabolomics can shed light on understanding metabolomic changes under different culture conditions and provides a theoretical basis for industrial applications of microalgae, as food with better high-quality active ingredients.