title: A new approach to ammonium sulphate feeding for fed-batch Arthrospira (Spirulina) platensis cultivation in tubular photobioreactor.
abstract: Arthrospira platensis was cultivated in tubular photobioreactor using different photosynthetic photon flux densities (PPFD) and protocols of (NH₄)₂SO₄ fed-batch supply. Results were evaluated by variance analysis selecting maximum cell concentration (X(m)), cell productivity (P(x)), nitrogen-to-cell conversion factor (Y(X/N)) and biomass, protein and lipid contents as responses. At PPFD of 120 and 240 μmol-photons/m² s, a parabolic profile of (NH₄)₂SO₄ addition aiming at producing biomass with 7% nitrogen content ensured X(m) values (14.1 and 12.2 g/L, respectively) comparable to those obtained with NaNO₃. At PPFD of 240 μmol-photons/m² s, P(x) (1.69 g/Ld) was 36% higher, although the photosynthetic efficiency (3.0%) was less than one-half that at PPFD of 120 μmol-photons/m² s. Biomass was shown to be constituted by about 35% proteins and 10% lipids, without any dependence on PPFD or kind of nitrogen source. These results highlight the possible use of (NH₄)₂SO₄ as alternative, cheap nitrogen source for A. platensis cultivation in tubular photobioreactors.
authors.affiliation: Dept. of Biochemical and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo 580, B-16, 05508-900, Brazil.
authors.forename: Lívia S
authors.initials: LS
authors.lastname: Ferreira
authors.forename: Mayla S
authors.initials: MS
authors.lastname: Rodrigues
authors.forename: Attilio
authors.initials: A
authors.lastname: Converti
authors.forename: Sunao
authors.initials: S
authors.lastname: Sato
authors.forename: João Carlos M
authors.initials: JC
authors.lastname: Carvalho
mesh_terms: D000645:Ammonium Sulfate / Q000378:metabolism*; D000704:Analysis of Variance; D058433:Photobioreactors / Q000382:microbiology*; D010788:Photosynthesis / Q000502:physiology; D053545:Spirulina / Q000378:metabolism*
chemical_list: D000645:Ammonium Sulfate