Cui Hongwu, Meng Fanping, Li Feng, Wang Yuejie, Duan Weiyan, Lin Yichen
Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, Shandong Province, China.
Department of Environmental Science and Engineering, Ocean University of China, No. 238, Songling Road, Qingdao, 266100, China.
AMB Express. 2017 Oct 10;7(1):187. doi: 10.1186/s13568-017-0488-9.
This study proposes a two-stage mixotrophic process for cultivating Chlorella vulgaris. Heterotrophic growth is the dominant step in Phase I (to increase microalgal biomass) and photoautotrophic growth occurs in Phase II (to improve biomass concentration and lipid production). The results show that the addition of the low-cost antioxidant sodium erythorbate (8 g L) significantly accelerates the growth of microalgae in the first stage with air aeration. Furthermore, a higher CO fixation rate was obtained in the second stage (at least 344.32 mg CO L day) with 10% CO aeration. This approximately corresponds to an increase of 177% over simple photoautotrophic cultivation with 10% CO aeration during the whole period. The two-stage cultivation strategy achieved a maximum C. vulgaris biomass concentration of 3.45 g L and lipid productivity of 43.70 mg L day, which are 1.85 and 1.64 times those arising due to simple photoautotrophy, respectively. Moreover, an analysis of the product's fatty acid profile indicates that C. vulgaris might be an ideal candidate for two-stage mixotrophic cultivation of a renewable biomass for use in biodiesel applications. Another interesting point to note from the study is that it is an insufficiency of N and CO that probably limits the further growth of C. vulgaris.
本研究提出了一种用于培养普通小球藻的两阶段混合营养过程。异养生长是第一阶段的主要步骤（用于增加微藻生物量），而光自养生长发生在第二阶段（用于提高生物量浓度和脂质产量）。结果表明，添加低成本抗氧化剂异抗坏血酸钠（8 g/L）在第一阶段通气的情况下能显著加速微藻生长。此外，在第二阶段，通气10% CO₂时获得了更高的CO₂固定率（至少344.32 mg CO₂/L·天）。这比整个时期通气10% CO₂的简单光自养培养大约提高了177%。两阶段培养策略实现了普通小球藻的最大生物量浓度为3.45 g/L，脂质生产率为43.70 mg/L·天，分别是简单光自养培养产生值的1.85倍和1.64倍。此外，对产物脂肪酸谱的分析表明，普通小球藻可能是用于生物柴油应用的可再生生物质两阶段混合营养培养的理想候选者。该研究另一个值得注意的有趣点是，氮和CO₂的不足可能限制了普通小球藻的进一步生长。
