The potential use of stickwater from a kilka fishmeal plant in Dunaliella salina cultivation.

In this study, the possibility of culturing Dunaliella salina in stickwater (SW) as the main effluent of fishmeal plants was evaluated. D. salina was grown in different media obtained by replacing standard Guillard medium (F/2) with SW at 0% (control), 10%, 25%, 50%, 75%, and 100% ratios. The cell density, pigment contents, proximate composition, saponification value, and fatty acids (FAs) profiles were measured for 14 days. SW was collected from a kilka fishmeal factory in northern Iran, and the characteristics indicated high concentrations of nitrate (242.00 mg L-1) and phosphate (11.13 mg L-1). A significant increase in the cell density was observed in 14 days when 75% SW was used. Moreover, SW significantly affected the pigment contents. The highest contents of chlorophylls, total carotenoids, and β-carotene (3.64 μg mL-1) were calculated in 75% SW. According to the algal proximate composition, the highest and lowest contents of lipid were accumulated in 75% and 100% SW, respectively (p < 0.05). The highest level of saturated FAs was observed in 75% SW compared with the others (p < 0.05). In conclusion, replacing F/2 with SW indicated the capability of D. salina to grow in a treated medium with 75% SW substitution as a bioremediator.