Lipid production combined with biosorption and bioaccumulation of cadmium, copper, manganese and zinc by oleaginous microalgae Chlorella minutissima UTEX2341

•Algae lipid production combined with heavy metal removal was practicable.•Heavy metals were removed mainly by intracellular accumulation.•Cd and Cu contributed to algae lipid productivity.•Heavy metal residue in lipid was within μg range and met the commercial demands.

Algae lipid production combined with heavy metal removal is a cost-effective and environment-friendly method for algae biofuel production and hazardous waste treatment. Chlorella minutissima UTEX 2341 had strong resistance to cadmium, copper, manganese and zinc ions under heterotrophic culture condition and could efficiently remove them through intracellular accumulation and extracellular immobilization. Meanwhile, lipid accumulation was not inhibited by heavy metals. Instead, the algae lipid content significantly increased by 21.07% and 93.90%, respectively with the addition of cadmium and copper. Furthermore, the heavy metal residue in lipid was within μg range and satisfied the commercial standard. This artificial wastewater-algae biofuel-heavy-metal integrated utilization technology offered a new alternative solution to the problems of energy shortage and environmental pollution.

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