Bioremediation of Domestic Wastewaters Integrated with Enhanced Biodiesel Production Using Novel Oleaginous Microalgae Mutated by Atmospheric and Room Temperature Plasma

This research analyzes the biochemical changes and cultivation feasibility of microalgae Desmodesmus sp. mutated using atmospheric and room temperature plasma (ARTP) in mixed sewage. The mutant strain AT151 was cultivated in different types of pretreated wastewater, achieving the highest biomass of >354 mg/L and increasing by >54% lipid production in wastewater pretreated by sediment. The fatty acid showed C16 and C18 in the majority >86%, and monounsaturated fatty acid content exceeded 18%, benefit for high-quality biodiesel. Besides nutrient removal was obvious in wastewater through cultivating mutant microalgae.The removal rate of TN, TP and TOC for mutant strains cultivated in wastewater was more than 87%, 94% and 47% respectively. Furthermore, the relationship between microalgae and bacteria was studied, resulting in regularity for the bacterial community being significantly different (P<0.05). The obvious phenomenon was the dominant bacteria changes that Brevundimonas balnearis and Synechocystis sp. developed the stable strains in cultivation, becoming a symbiotic relationship with mutant microalgae. The dominant bacteria performed obvious metabolism using functional KEGG prediction, mainly affecting amino acid, carbohydrate, and growth factor metabolism. It is scientifically important and feasible for microalgae in wastewater cultivation to improve microalgae biomass and lipid production.