title: An optical-density-based feedback feeding method for ammonium concentration control in Spirulina platensis cultivation.
abstract: Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium- N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l·d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4 mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.
authors.affiliation: Collage of Light Industry and Food Science, South China University of Technology, Guangzhou 510640, P. R. China.
authors.forename: Yilu
authors.initials: Y
authors.lastname: Bao
authors.forename: Shumei
authors.initials: S
authors.lastname: Wen
authors.forename: Wei
authors.initials: W
authors.lastname: Cong
authors.forename: Xia
authors.initials: X
authors.lastname: Wu
authors.forename: Zhengxiang
authors.initials: Z
authors.lastname: Ning
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D001431:Bacteriological Techniques / Q000379:methods*; D001639:Bicarbonates / Q000378:metabolism*; D018533:Biomass; D001709:Biotechnology / Q000379:methods; D002734:Chlorophyll / Q000032:analysis; D003470:Culture Media / Q000737:chemistry*; D005246:Feedback; D009584:Nitrogen / Q000378:metabolism; D013053:Spectrophotometry / Q000379:methods*; D053545:Spirulina / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001639:Bicarbonates; D003470:Culture Media; D002734:Chlorophyll; C027043:ammonium bicarbonate; D009584:Nitrogen