title: Effects of different nitrogen and phosphorus concentrations on the growth, nutrient uptake, and lipid accumulation of a freshwater microalga Scenedesmus sp.
abstract: Microalgae have high potential to remove inorganic nutrients from wastewater and to produce biodiesel. Effects of nitrogen and phosphorus concentrations on growth, nutrient uptake, and lipid accumulation of a freshwater microalga Scenedesmus sp. LX1 were studied. Scenedesmus sp. LX1's growth was in accordance with the Monod model. The following Monod parameters were obtained: the N- and P-saturated maximum growth rate was 2.21 x 10(6) cells m L(-1)d(-1), and the half-saturation constants of N and P uptake were 12.1 mg L(-1) and 0.27 mg L(-1), respectively. In the nitrogen/phosphorus ratio of 5:1-12:1, 83-99% nitrogen and 99% phosphorus could be removed. In conditions of nitrogen (2.5 mg L(-1)) or phosphorus (0.1 mg L(-1)) limitation, Scenedesmus sp. LX1 could accumulate lipids to as high as 30% and 53%, respectively, of its algal biomass. The lipid productivity/unit volume of culture, however, was not enhanced. Further research should be made on how to enhance both lipid content and lipid productivity.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xin
authors.forename: Hong-ying
authors.initials: HY
authors.lastname: Hu
authors.forename: Gan
authors.initials: G
authors.lastname: Ke
authors.forename: Ying-xue
authors.initials: YX
authors.lastname: Sun
mesh_terms: D018533:Biomass; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D003470:Culture Media / Q000737:chemistry; D056890:Eukaryota / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D052756:Nutritional Sciences; D010758:Phosphorus / Q000737:chemistry*; D012044:Regression Analysis; D044444:Scenedesmus / Q000378:metabolism*; D013997:Time Factors
chemical_list: D003470:Culture Media; D008055:Lipids; D010758:Phosphorus; D009584:Nitrogen