Bioremediation of minkery wastewater and astaxanthin production by Haematococcus pluvialis

A two-stage system was designed for culturing and induction processes of H. pluvialis. H. pluvialis was cultivated in minkery wastewater and compared with the conventional Bold's basal medium, and grew better in diluted (1.5%) minkery wastewater, yielding a biomass production of 906.3 ± 34.0 mg L−1. Total nitrogen and total phosphorus were also removed successfully. In the following induction stage, nitrogen-deprived vegetative cells were exposed to high light intensity for astaxanthin production, and the resultant production was 39.72 ± 1.69 mg L−1. Employing the diluted wastewater, a mixotrophic induction strategy was also tested by using a series of acetate and NaCl concentrations. The findings indicated that the optimal combination for astaxanthin production was 38.14 mM acetate and 0.58% (w/v) NaCl. And the optimal astaxanthin concentration was 67.95 ± 3.93 mg L−1 after a 12-day induction period. This study concludes that H. pluvialis offers a potential opportunity for treating minkery wastewater and producing high-value astaxanthin.