Belaich J P, Senez J C, Murgier M
J Bacteriol. 1968 May;95(5):1750-7. doi: 10.1128/jb.95.5.1750-1757.1968.
A microcalorimetric method for measuring the influence of extracellular glucose concentration on the rate of catabolism is described. This method has been applied to anaerobically growing cultures of Zymomonas mobilis and of a respiratory-deficient ("petite") mutant of Saccharomyces cerevisiae (strain YFa). The Michaelian kinetics recorded with both organisms were apparently related to glucose transport. With Z. mobilis, it was found that, in the range of glucose concentrations at which this organism was growing exponentially, cell activity was limited by the maximal rate of the catabolic enzymes; at lower concentrations, glucose transport was the rate controlling step. The metabolic activity of yeast always depended on external glucose concentration; when this was lowered under a threshold, a change of kinetics took place. The microcalorimetric method described seems to be widely applicable to kinetic studies of the permeation of metabolizable substrates in microorganisms.
本文描述了一种用于测量细胞外葡萄糖浓度对分解代谢速率影响的微量量热法。该方法已应用于运动发酵单胞菌和酿酒酵母呼吸缺陷型(“小菌落”)突变体(YFa菌株)的厌氧培养物。两种生物体记录的米氏动力学显然与葡萄糖转运有关。对于运动发酵单胞菌,发现在该生物体指数生长的葡萄糖浓度范围内,细胞活性受分解代谢酶的最大速率限制;在较低浓度下,葡萄糖转运是速率控制步骤。酵母的代谢活性始终取决于外部葡萄糖浓度;当葡萄糖浓度降至阈值以下时,动力学发生变化。所描述的微量量热法似乎广泛适用于微生物中可代谢底物渗透的动力学研究。