Ruming Z, Yi L, Zhixiong X, Ping S, Songsheng Q
College of Life Sciences, Wuhan University, 430072, Wuhan, PR China.
J Biochem Biophys Methods. 2000 Nov 20;46(1-2):1-9. doi: 10.1016/s0165-022x(00)00124-x.
A microcalorimetric technique based on the bacterial heat-output was explored to evaluate the stimulatory effect of La(3+) on Escherichia coli. The power-time curves of the growth metabolism of E. coli and the effect of La(3+) on it were studied using an LKB-2277 BioActivity Monitor, stopped-flow method, at 37 degrees C. For evaluation of the results, the maximum power (P(max)), the growth rate constants (k) and the heat effects (Q(LOG), Q(STAT)) for the log phase, the stationary phase and the total heat effect (Q(T)) for E. coli were determined. The microcalorimetric method agreed with the conventional methods, such as cell numbers and biomass. La(3+) in the concentration ranges of 0-400 microg/ml has stimulatory effects on E. coli, while La(3+) ion of higher concentrations (>400 microg/ml) can inhibit the growth. This phenomenon is very similar to those observed from the in vitro cells and tissues from animals, plants and some microorganisms by other methods.
探索了一种基于细菌产热的微量热技术来评估La(3+)对大肠杆菌的刺激作用。使用LKB - 2277生物活性监测仪的停流法，在37℃下研究了大肠杆菌生长代谢的功率 - 时间曲线以及La(3+)对其的影响。为了评估结果，测定了大肠杆菌对数期的最大功率（P(max)）、生长速率常数（k）和热效应（Q(LOG)、Q(STAT)）、稳定期的热效应以及总热效应（Q(T)）。微量热法与传统方法（如细胞数量和生物量）结果一致。浓度范围在0 - 400μg/ml的La(3+)对大肠杆菌有刺激作用，而更高浓度（>400μg/ml）的La(3+)离子会抑制其生长。这种现象与通过其他方法在动物、植物和一些微生物的体外细胞及组织中观察到的现象非常相似。
