Fed-batch cultivation of Arthrospira (Spirulina) platensis: potassium nitrate and ammonium chloride as simultaneous nitrogen sources.
Arthrospiraplatensis was cultivated in minitanks at 13 klux, using a mixture of KNO(3) and NH(4)Cl as nitrogen source. Fed-batch daily supply of NH(4)Cl at exponentially-increasing feeding rate allowed preventing ammonia toxicity and nitrogen deficiency, providing high maximum cell concentration (X(m)) and high-quality biomass (21.85 mg chlorophyll g cells(-1); 20.5% lipids; 49.8% proteins). A central composite design combined to response surface methodology was utilized to determine the relationships between responses (X(m), cell productivity and nitrogen-to-cell conversion factor) and independent variables (KNO(3) and NH(4)Cl concentrations). Under optimum conditions (15.5mM KNO(3); 14.1mM NH(4)Cl), X(m) was 4327 mg L(-1), a value almost coincident with that obtained with only 25.4mM KNO(3), but more than twice that obtained with 21.5mM NH(4)Cl. A 30%-reduction of culture medium cost can be estimated when compared to KNO(3)-batch runs, thus behaving as a cheap alternative for the commercial production of this cyanobacterium.
Rodrigues
M S
MS
Department of Biochemical and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, B-16, 05508-900 São Paulo, Brazil.
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D000641:Ammonia / Q000032:analysis; D000643:Ammonium Chloride / Q000494:pharmacology*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000494:pharmacology; D002734:Chlorophyll / Q000032:analysis; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008055:Lipids / Q000032:analysis; D015999:Multivariate Analysis; D009566:Nitrates / Q000032:analysis / Q000494:pharmacology*; D009584:Nitrogen / Q000494:pharmacology*; D017680:Potassium Compounds / Q000494:pharmacology*; D011506:Proteins / Q000032:analysis; D012044:Regression Analysis; D053545:Spirulina / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development*; D013997:Time Factors
D008055:Lipids; D009566:Nitrates; D017680:Potassium Compounds; D011506:Proteins; D000643:Ammonium Chloride; D002734:Chlorophyll; D002244:Carbon; D000641:Ammonia; D009584:Nitrogen; C023844:potassium nitrate