Microalgae cultivation and harvest
Tetraselmis striata M8, which is a marine algae with high lipid
accumulation ability, was cultured in 40 L airlift photobioreactors
at the University of Queensland. F/2 medium was used as the
growth media. Culture pH was kept constant at 8.5 ± 0.2 by CO2
injection with an electronic controller, and the depletion of nutrients
(NO3
and PO4
3) was tested using seawater aquaria nutrients
kits (DAPI Aquarium Pharmaceuticals for NO3
and Nutrafin for
PO4
3). Nitrogen starvation strategy was used to accumulate lipids
in the algal cells. After 5 days cultivation for algae growth and
3 days for lipid accumulation, 90 L algal culture was concentrated
to a paste by centrifugation in a Beckman Coulter, Allegra™ X-12
at 3750 rpm for 3 min in 800 ml batches. Centrifugation was conducted
for a short time to avoid mechanical cell disruption.