Monogalactosyldiacylglycerols (MGDGs) from microalgae containing a high proportion of polyunsaturated fatty acids (PUFAs) have enormous potential applications in various industries. In this study, the productivity and fatty acid composition of MGDGs from three microalgae in commercialized production, Chlorella sorokiniana GT, Nannochloropsis oceanica IMET1, and Arthrospira platensis, were evaluated under nitrogen-sufficient (+N) and nitrogen-deficient (-N) conditions. Under +N conditions, higher productivities of MGDGs from C. sorokiniana GT1, N. oceanica IMET1, and A. platensis were obtained with 16.3, 4.3, and 1.3 mg/L/day, respectively. In agreement with a high ratio of PUFAs in MGDGs, they accounted for 56%, 66%, and 47% of the total fatty acids in MGDG correspondingly. α-linoleic acid (ALA), eicosapentaenoic acid (EPA), and γ-linoleic acid (GLA) were the specific PUFAs of the three microalgae. The proportions of the specific PUFAs in MGDG accounted for 26%, 44%, and 63% of total specific PUFAs, respectively. Considering the production, cost of microalgae biomass and price of MGDG, the commercialized microalgae C. sorokiniana GT1 and A. platensis showed great potential to produce MGDGs with a high content of PUFAs, in contrast to N. oceanica IMET1, with its high biomass cost and low production. This study provides basic data for the extraction and separation of microalgae lipids from commercialized microalgae, which is helpful to promote the commercialization of microalgae.
Keywords: ALA; EPA; GLA; MGDG; Microalgae; PUFAs.