Enhanced production of microalgal lipids using a heterotrophic marine microalga Thraustochytrium sp. BM2

In this study, the potential of Thraustochytrium sp. BM2 for cost-effective lipid production was investigated. Lipid content and productivity of BM2 reached 76% and 37 mg/L/h when corn steep liquor (12.5 g/L) and glycerol (10 g/L) was used as nitrogen and carbon source respectively. Supplementing an optimal amount of sea salt (2% w/v) further enhanced the lipid content to 79%. The inoculum size and age were also evaluated for their effect on lipid accumulation. A 48-h pre-culture at 0.15 g/L loading further improved the lipid productivity to 43.86 mg/L/h (or 1.052 g/L/d), which is a 340% increase when compared with the control test. Thus, Thraustochytrium sp. BM2 strain could serve as a low-cost and high-lipid-yield heterotrophic lipid producer using glycerol (a by-product of biodiesel manufacturing process) as carbon source and an inexpensive nitrogen source (i.e., corn steep liquor).