Extraction pre-treatment
In experiments where dried microalgae was used, the microalgal
paste was dried at 85 C in an oven (Model UNE 500 PA,
Memmert GmbH+Co., Germany) for 16 h. A ring mill was then used
to grind the dried biomass into powder. In experiments involving
wet microalgae, the microalgal paste obtained from bench top centrifugation
was used directly without further treatment. The solid
concentration of the paste was 30 wt%. This was determined by
drying a portion of the paste and comparing its pre-dried mass
to that of the corresponding dried biomass. Both microalgal
powder and paste were stored at 5 C for no longer than
1.5 months before they were used for lipid extraction.