Abstract:Eutrophication wastewater from twice filtered fishponds was used as the culture medium,into which carbon,nitrogen,and phosphorus were added.The influences of different concentrations of inorganic carbon,total nitrogen,and total phosphorus of sewage on biomass,li-pid content,and hydrocarbon content of Botryococcus braunii were studied.The following results were reported: (1) Using NaHCO3 as the carbon source,the biomass and lipid content of B. braunii were the highest at the inorganic carbon concentration of 5-10 mg/L,while the highest hydrocarbon content was at the inorganic carbon concentration of 15 mg/L.(2) Using KNO3 as the nitrogen source,the biomass of B. braunii was the highest at the total nitrogen concentration of 15 mg/L; the highest lipid content was at the total nitrogen concentration of 2 mg/L; the highest hydrocarbon content was at the total nitrogen concentration of 20 mg/L.(3) Using KH2PO4 as the phosphorus source,the biomass of B. braunii was the highest at a total phosphate concentration of 2 mg/L while the highest lipid content and the highest hydrocarbon content were at a total phosphorus concentration of 1.5 mg/L.