Production of Singl Cell Proteine and Singl Cell Oil from the co- culture of Yarrowia lipolytica yeast and Aspergillus niger fungus in the effluent from Kilka (Stick water) fishmeal production plant

From an environmental point of view, one of the major problems of the fish meal industry is discharges of stickwater (SW), an intermediate product from pressing process of fish meal, which is rich in organic matter and nutrients and can be used as a substrare for Recovery and valorization such as single cell protein and lipid. In this study, Yarrowia lipolytica and Aspergillus niger were used to produce single cell protein (SCP) and single cell oil (SCO) using Kilka stick water as the source of medium. The pattern of the yeast and fungus growth was studied by plate count method. Also the amount of remaining oil and remaining protein was analyzed for values of total protein, and total lipid. Data was analyzed by randomized complete block design and the results showed that yeast, as a fat-storing microorganism, had a higher ability to grow on SW, compared to protein-storing fungus within 120 hrs and produced more microbial biomass in a shorter time. 100% yeast treatment had the highest SW lipid reduction rate (more than 50%, equivalant to 21.7 mg/L) in 120 hrs, while 100% fungus treatment showed the lowest rate. Regarding SW protein reduction, 75% yeast-25% fungus treatment had the highest rate. Overally, Yarrowia lipolytica in single culture had the highest growth and SCO production and 75% yeast-25% fungus mixed culture treatment had the highest SCP production. Based on the results obtained from this study, application of pure Kilka stick water is suitable for production of SCP and SCO and reduction of its organic matter as wastewater.