微生物代谢的唯象关系和趋优行为

从非平衡态热力学出发 ,探讨了微生物细胞在追求最高生长速率的优化模式下的动力学行为 .将微生物的生长过程分成分解代谢和合成代谢两个过程 (黑箱模型 ) ,通过唯象关系优化生长速率 ,得到了最优的合成代谢和分解代谢速率与自由能变化的关系 .计算表明 ,该关系式可以描述实际体系的生长过程 .进一步将微生物的生长过程划分为分解代谢、合成代谢、ATP的生成与消耗 3个反应 ,得到了与黑箱模型同样的优化结果 ,并且探讨了总偶合度与单步反应偶合度的关系 .所用的方法可以用来分析细胞的趋优行为 .

PHENOMENOLOGICAL RELATIONSHIP AND OPTIMIZATION OF MICROBIAL METABOLISM

Based on non-equilibrium thermodynamics, the dynamic behaviour of microbial cells trying to achieve maximal growth rate was studied. The growth process was divided into anabolic and catabolic reactions. By optimizing the anabolic flow through the phenomenological relationship, the optimal growth rate and catabolic flow were deduced. Calculations with regard to practical cultivation systems proved that the equations held good for real microbial cells. Futhermore, the metabolic process was divided into three reactions: anabolism , catabolism and the synthesis and utilization of ATP. The same equations as those deduced in black box model were obtained and the relationship of the total coupling degree and the coupling degree of a single step was presented.