Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
Department of Microbial and Nano Materials, Mokwon University, 88 Doanbuk-ro, Yuseong-gu, Daejeon, 35349, Republic of Korea.
Sci Rep. 2019 May 2;9(1):6830. doi: 10.1038/s41598-019-43366-5.
The culture conditions and media composition for the heterotrophic culture of an axenic strain of Ettlia sp. YC001 were firstly optimized using the Plackett-Burman design (PBD) and response surface methodology (RSM). The strain successfully showed higher productivity in the basal media without any light illumination at 32.2 to 33.3 °C. The PBD results showed that the most effective components for biomass productivity of Ettlia sp. were fructose and yeast extract for sources of C and N, respectively. The RSM results showed an optimal level of 72.2 g/L for fructose and 21.5 g/L for yeast extract, resulting in 46.1 g/L biomass with a lipid content of 13.8% over a course of 9 days. Using a 5 L scaled-up fermentation system for 6 days, the production of biomass and lipids was 7.21 g/L/day and 1.18 g/L/day, respectively. Consequently, heterotrophic cultivation of Ettlia sp. YC001 provided much higher production of biomass and lipids than those of autotrophic cultivation. As further research, the use of substitute substrates instead of fructose and yeast extract should be developed to reduce production costs.
首先采用 Plackett-Burman 设计（PBD）和响应面法（RSM）优化了无菌菌株 Ettlia sp. YC001 的异养培养的条件和培养基组成。该菌株在 32.2 至 33.3°C 、无任何光照的基础培养基中成功表现出更高的生产力。PBD 结果表明，对 Ettlia sp. 的生物量生产力最有效的成分分别是果糖和酵母提取物，作为 C 和 N 的来源。RSM 结果表明，果糖的最佳水平为 72.2g/L，酵母提取物为 21.5g/L，在 9 天的过程中产生 46.1g/L 的生物质，脂质含量为 13.8%。使用 5L 放大发酵系统进行 6 天，生物质和脂质的产量分别为 7.21g/L/天和 1.18g/L/天。因此，与自养培养相比，Ettlia sp. YC001 的异养培养提供了更高的生物质和脂质产量。作为进一步的研究，应该开发替代底物而不是果糖和酵母提取物的使用，以降低生产成本。
