Interaction of phosphorus and iron on growth and lipid production of green microalga, Desmodesmus quadricauda

Abstract

The interaction of phosphorus (P) and iron (Fe) on growth and lipid production of microalga,Desmodesmus quadricauda was studied. The experiments were performed as factorial design (5x5) with 5 concentrations of phosphorus 28, 142, 285, 427 and 569 mg P/l and iron 15 ,10 ,5 ,1 and 02 mg Fe/l. The concentration of P and Fe in Chlorella medium was used as the control (285 mg P/l and 10 mg Fe/l). The result showed the interaction of phosphorus and iron on specific growth rate (p = 0.01), biomass (p = 4.00x10-13), lipid content (p = 8.13x10-5) and lipid yield (p = 0.009) of alga. The maximum specificgrowth rate (0.23±0.06 /d) and biomass (1.91±0.09 g/l) of alga were obtained with cultivated in P:Fe 142:10 and 427:2 mg/l, respectively. The alga cultivated in P:Fe 569:1 mg/l showed the maximum lipid content,lipid yield and lipid productivity of 24.98±5.03%, 0.41±0.06 g/l and 45.06±5.23 mg/l/d, respectively. The present study showed that P:Fe 569:1 mg/l was the optimum ratio for cultivation of D. quadricaudabecause this alga gave the highest lipid yield. The result indicated that this alga could be used as an alternatively potential source for biodiesel production.