Yan Riming, Zhang Zhibin, Zeng Qinggui, Du Zhu, Chu Ju
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Sheng Wu Gong Cheng Xue Bao. 2010 Sep;26(9):1239-48.
To investigate the energy utilization efficiency of Synechococcus sp. PCC7942 under mixotrophic conditions, we studied its growth characteristics in mixotrophic cultures with glucose and acetic acid respectively and discussed the carbon metabolism and energy utilization based on metabolic flux analysis. Results showed that both glucose and acetate could better enhance the growth of Synechococcus sp. PCC7942, and the latter was more effective. The metabolic flux through glycolytic pathway in mixotrophic cultures was stimulated by glucose whereas depressed by acetate, while the flux through the tricarboxylic acid cycle increased in both cases. Under mixotrophic conditions, glucose makes more significant impact on the diminishment of photochemical efficiency of Synechococcus sp. PCC7942. Although the contribution of light energy was smaller, the cell yields based on total energy in mixotrophic cultures were higher comparing with photoautotrophic culture. The energy conversion efficiencies based on ATP synthesis in photoautotrophic culture, mixotrophic cultures with glucose and with acetate were evaluated to be 6.81%, 7.43% and 8.77%, respectively.
为了研究聚球藻属PCC7942在混合营养条件下的能量利用效率，我们分别研究了其在添加葡萄糖和乙酸的混合营养培养中的生长特性，并基于代谢通量分析讨论了碳代谢和能量利用情况。结果表明，葡萄糖和乙酸盐都能更好地促进聚球藻属PCC7942的生长，且后者更有效。混合营养培养中通过糖酵解途径的代谢通量受葡萄糖刺激而受乙酸盐抑制，而两种情况下通过三羧酸循环的通量均增加。在混合营养条件下，葡萄糖对聚球藻属PCC7942光化学效率的降低影响更大。虽然光能的贡献较小，但与光合自养培养相比，混合营养培养中基于总能量的细胞产量更高。光合自养培养、添加葡萄糖的混合营养培养和添加乙酸盐的混合营养培养基于ATP合成的能量转换效率分别评估为6.81%、7.43%和8.77%。
