聚球藻7942混养培养中碳代谢与能量利用

Carbon metabolism and energetic utilization of Synechococcus sp. PCC7942 under mixotrophic condition

摘要:

为了考察聚球藻7942在混养条件下的能量利用效率，分别以葡萄糖和乙酸为碳源开展了聚球藻7942的混养培养研究，并在此基础上利用代谢通量分析方法对聚球藻7942混养条件下的碳代谢和能量利用进行了探讨。结果表明：葡萄糖和乙酸均能促进藻细胞生长，且乙酸促进藻细胞生长的作用更为明显；葡萄糖利用可明显增加藻细胞糖酵解途径中碳代谢流量，而乙酸利用则导致糖酵解途径中碳代谢流量减小，两种有机碳源均增加了柠檬酸循环中碳代谢流量；有机碳源导致藻细胞光化学效率下降，而葡萄糖较之乙酸降低藻细胞光化学效率更为明显。虽然混养条件下光

Abstract:

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.