Sun Xiao-Man, Ren Lu-Jing, Ji Xiao-Jun, Huang He
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China.
Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, People's Republic of China.
AMB Express. 2018 Sep 21;8(1):150. doi: 10.1186/s13568-018-0681-5.
Enhancing lipid productivity and reducing oxidative damage is essential for lipid overproduction in microalgae. In this study, addition of 20 mg/L fulvic acid (FA) resulted a 34.4% increase of lipid yield in Schizochytrium sp. Furthermore, the cooperative effect of FA and EDTA on cell growth and lipid production was investigated. The combined addition of 20 mg/L FA and 1.0 g/L EDTA yielded a maximal cell dry weight of 130.7 g/L and lipid productivity of 1.16 g/L/h, representing 36.4% and threefold increase over the non-supplemented group, respectively. Moreover, compared with the non-supplemented group, the combined addition strategy exhibited overall lower levels of reactive oxygen species and malondialdehyde, which accompanied with 66.7% and 81.9% higher superoxide dismutase and catalase activity, respectively. Furthermore, a 24.1-37.1% increase of malic enzyme and 19.4-25.2% decrease of phosphoenolpyruvate carboxylase activity was observed during the entire fermentation stage (0-108 h). Results suggested that the combined addition strategy not only enhanced lipid accumulation, but also prevented the lipid peroxidation.
提高脂质生产力并减少氧化损伤对于微藻中脂质的过量生产至关重要。在本研究中，添加20mg/L富里酸（FA）使裂殖壶菌属的脂质产量提高了34.4%。此外，还研究了FA和EDTA对细胞生长和脂质生产的协同作用。联合添加20mg/L FA和1.0g/L EDTA时，细胞干重最高可达130.7g/L，脂质生产力为1.16g/L/h，分别比未添加组提高了36.4%和增加了两倍。此外，与未添加组相比，联合添加策略表现出较低的活性氧和丙二醛水平，同时超氧化物歧化酶和过氧化氢酶活性分别提高了66.7%和81.9%。此外，在整个发酵阶段（0-108小时），苹果酸酶活性提高了24.1-37.1%，磷酸烯醇式丙酮酸羧化酶活性降低了19.4-25.2%。结果表明，联合添加策略不仅提高了脂质积累，还防止了脂质过氧化。
