Biomass production of a Scenedesmus sp. under phosphorous-starvation cultivation condition.

Microalgae-based bioenergy has gained extensive attention, but the consumption of non-renewable resource such as phosphorous is inevitable in the production of its feedstock. In this work, the minimal phosphorous consumption for algal biomass production of Scenedesmus sp. LX1 was investigated by monitoring the growth and nutrient uptake under two different cultivation modes: phosphorous-starvation and luxury-nutrient. The results showed that continuous nitrogen and phosphorous feeding in luxury-nutrient mode had no stimulating effect on biomass productivity at the nutrient level in this study, TN: 245 mg L(-1), TP: 5.4 mg L(-1). However, the sustained growth of biomass after the exhaust of phosphate in phosphorous-starvation mode led to significant increase in the biomass yield of phosphorous up to 160 g biomass/g -P, which was nearly six times more than that with nutrient feeding. To minimize phosphorous resource consumption in production of algal biomass, a phosphorous-starvation cultivation mode is proposed.