Lipid accumulation and antioxidant activity in the eukaryotic acidophilic microalga Coccomyxa sp. (strain onubensis) under nutrient starvation

The chlorophtye Coccomyxa sp. (strain onubensis)
growing under either inorganic phosphorus or sulfur starvation
showed, unlike other non-extremophile microalgae, the
ability to grow still for a period of 2 weeks with retention of
high activity of photosystem II, due to P and S reserves in the
microalga. Lutein and β-carotene contents slightly increased
for a few days in nitrogen-lacking cultures only, with no major
impact on productivity due to cease of growth. Maximum
fatty acid content of Coccomyxa sp. (strain onubensis) growing
in nutrient-lacking culture media accounted for about
13%of dry biomass and about 50%of the total lipid fraction,
linolenic (C18:3) being the most abundant fatty acid. The lipid
content of this microalga is on the average of nonextremophile
microalgae, but it has the advantage of producing
in highly acidic culture media (pH 2.5, and even lower)
which allow its outdoor production-preserving cultures from
other microalgae contamination. Nutrient-limited cultures
showed a significant increase in the intracellular activity levels
of the enzymes glutathione reductase (GR), ascorbate peroxidase
(APX) and catalase (CAT), indicating a connection