Dept. of Biochemical and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo 580, B-16, 05508-900, Brazil.
Biotechnol Prog. 2010 Sep-Oct;26(5):1271-7. doi: 10.1002/btpr.457.
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.
钝顶螺旋藻在管式光生物反应器中培养，采用不同的光合光子通量密度 (PPFD) 和 (NH₄)₂SO₄ 补料分批供应方案。通过方差分析选择最大细胞浓度 (X(m))、细胞生产率 (P(x))、氮到细胞的转化率 (Y(X/N)) 和生物量、蛋白质和脂质含量作为响应来评估结果。在 PPFD 为 120 和 240 μmol-photons/m² s 时，添加 (NH₄)₂SO₄ 的抛物线曲线旨在生产含 7%氮的生物质，可确保 X(m) 值 (分别为 14.1 和 12.2 g/L) 与使用 NaNO₃ 获得的值相当。在 PPFD 为 240 μmol-photons/m² s 时，P(x) (1.69 g/Ld) 提高了 36%，尽管光合效率 (3.0%) 不到 PPFD 为 120 μmol-photons/m² s 时的一半。生物质由约 35%的蛋白质和 10%的脂质组成，与 PPFD 或氮源的种类无关。这些结果突出表明，(NH₄)₂SO₄ 可作为替代廉价氮源，用于在管式光生物反应器中培养钝顶螺旋藻。
