Revalorization of Neochloris oleoabundans biomass as source of biodiesel by concurrent production of lipids and carotenoids

The production of valuable co-products is considered a suitable pathway to reduce the cost of biofuel production from microalgae. With that purpose, we studied the effect of different culture factors on the production of triacylglycerides (TAG) and carotenoids by Neochloris oleoabundans. The highest TAG productivity (up to 154 mg L− 1 d− 1) was achieved in cultures supplemented with 3 mM nitrate, and after six days of nitrogen starvation. Increasing the nitrate concentration led to a decrease in TAG productivity caused by a sharp reduction in the cell TAG content. Lack of carbon hampered TAG accumulation, thus decreasing its productivity to 20 mg L− 1d− 1, and light intensity did not affect the TAG productivity. Under culture conditions leading to maximum TAG productivity, carotenoids comprised 2% of dry biomass achieving productivities close to 9 mg L− 1 d− 1. High-value carotenoids (lutein and astaxanthin) accounted for up to 60% of total carotenoids. Although the optimal culture conditions for the production of carotenoids did not match with those for the optimized generation of TAG, data herein reported show the potential of N. oleoabundans for the production of both products and support the co-production of carotenoids as a possible way to pay off the cost of biodiesel production from this strain.