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Glycerol and Acetate Additions to Maximize Lipid Content in High‐Density Cultures of Phagotrophic Alga Ochromonas danica
Author(s) -
Lin Zhongye,
Li Cong,
Ju LuKwang
Publication year - 2019
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1002/aocs.12183
Subject(s) - glycerol , food science , acetic acid , chemistry , lipid accumulation , biochemistry , sodium acetate , chromatography
Waste organics conversion to algal lipid is environmentally friendly and it promotes sustainability. Achieving high‐lipid content in cells is crucial to the economic feasibility of algal lipid production and collection. Here, a phagotrophic microalga Ochromonas danica was grown on waste ketchup and then stimulated to accumulate high‐lipid content using glycerol and acetate. Individually, glycerol and acetate could increase lipid synthesis. Sequential glycerol‐then‐acetate addition was more effective; for an O. danica culture with 0.25 g L −1 cells, the intracellular lipid content was increased to 70–80% (w/w) in 6–12 hours. However, acetate added at >1 g L −1 damaged cells. For high‐density (25 g L −1 ) fermentations, glycerol and acetate addition strategies were evaluated to overcome this inhibition. Results indicated that glycerol could be added in batches or continuously as long as the amount was sufficient to satisfy the glycerol consumption rate of 6 mg (g cells‐hour) −1 while acetic acid needed to be added continuously, optimal at a rate of 0.27–0.30 g hour −1 or 12–14 mg (g cells‐hour) −1 . Intracellular lipid content could reach 70–80% after 2‐day supplementation of glycerol and acetic acid. The methods of glycerol/acetate additions developed here enhance algal lipid production and enable effective conversion of organic wastes to algal lipids as sustainable bioproducts.