Evaluation of the operational conditions in the production and morphology of Chlorella sp.

Abstract It was evaluated the effect of operational conditions in the production of Chlorella sp. after its selection from genus Chlorella sp., Scenedesmus sp., Nannochloris sp., Tetraselmis sp. and Dunaliella salina. Microalgae were inoculated in drinking water with addition of NPK fertilizer (N 24%, P 24%, K 18%), at a concentration of 0.5 g/L, agitation of 150 rpm, temperature 25 °C, light intensity of 1680 lumens at a color temperature of 6400K, without pH control for 8 days. The cellular concentrations obtained were 3.72x107 (Chlorella sp.), 1.36x107 (Scenedesmus sp.), 3.55x107 (Tetraselmis sp.), 5.74x107 (Nannochloris sp.) and 3.45x106 (Dunaliella salina), where the microalgae Chlorella sp., shows invasive capacity in drinking water cultivations. Applying the 2n-p fractional factorial design concept for the elemental composition of the microalgae and the cellular morphology, it was obtained 44.33% of C, 7.09% of H, 8.53% of N and 0.84% of S for the Chlorella sp.摘要：本研究从小球藻属（Chlorella sp.）、栅藻属（Scenedesmus sp.）、拟小球藻属（Nannochloris sp.）、四鞭藻属（Tetraselmis sp.）以及盐生杜氏藻（Dunaliella salina）中筛选目标藻株后，评估了培养条件对小球藻（Chlorella sp.）规模化生产的影响。将微藻接种于添加了NPK肥料（氮含量24%、磷含量24%、钾含量18%）的饮用水中，肥料浓度设置为0.5 g/L，搅拌速率150 rpm，培养温度25 ℃，光照强度1680流明、色温6400K，且不调控pH值，连续培养8天。最终测得的细胞浓度分别为：小球藻（Chlorella sp.）3.72×10^7、栅藻（Scenedesmus sp.）1.36×10^7、四鞭藻（Tetraselmis sp.）3.55×10^7、拟小球藻（Nannochloris sp.）5.74×10^7，以及盐生杜氏藻（Dunaliella salina）3.45×10^6，其中小球藻（Chlorella sp.）在饮用水培养体系中展现出较强的入侵增殖能力。针对微藻的元素组成与细胞形态，采用2^n-p部分析因设计方案开展分析，测得小球藻（Chlorella sp.）的元素占比分别为：碳（C）44.33%、氢（H）7.09%、氮（N）8.53%以及硫（S）0.84%。