Mulder M M, Teixeira de Mattos M J, Postma P W, van Dam K
Biochim Biophys Acta. 1986 Sep 10;851(2):223-8. doi: 10.1016/0005-2728(86)90129-5.
The energetics of growth of Escherichia coli FRAG 1 under potassium-limited growth conditions and with glucose as sole carbon and energy source were studied in the chemostat and compared with those of a mutant, FRAG 5, defective in the high-affinity potassium uptake system. The steady-state concentration of biomass decreased with increasing growth rate and was the same in both parent and mutant. For each growth rate, the rate of production of ATP was higher in the parent than the mutant strain. Under potassium-limited conditions, FRAG 1 has at least two potassium uptake systems, an inducible high-affinity uptake system and a constitutive low-affinity uptake system (Rhoads, D.B., Waters, F.B. and Epstein, W. (1976) J. Gen. Physiol. 67, 325-341). Apparently, the presence of the high-affinity uptake system in the parent leads to an energy drain. We suggest that this energy drain is due to futile cycling of potassium ions. On the basis of a mosaic non-equilibrium thermodynamic description of bacterial growth, it is concluded that the growth behaviour under potassium limitation corresponds to that expected for a catabolite limitation.
在恒化器中研究了大肠杆菌FRAG 1在钾限制生长条件下以葡萄糖作为唯一碳源和能源时的生长能量学，并与高亲和力钾摄取系统有缺陷的突变体FRAG 5进行了比较。生物量的稳态浓度随生长速率的增加而降低，亲本菌株和突变体中的浓度相同。对于每种生长速率，亲本菌株中ATP的产生速率高于突变体菌株。在钾限制条件下，FRAG 1至少有两种钾摄取系统，一种是可诱导的高亲和力摄取系统，另一种是组成型低亲和力摄取系统（Rhoads, D.B., Waters, F.B. 和 Epstein, W. (1976) J. Gen. Physiol. 67, 325 - 341）。显然，亲本菌株中高亲和力摄取系统的存在导致了能量消耗。我们认为这种能量消耗是由于钾离子的无效循环所致。基于细菌生长的镶嵌非平衡热力学描述，得出结论：钾限制下的生长行为与分解代谢物限制时预期的行为一致。
