Hondzo Miki, Wüest Alfred
St. Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota 55414-2196, USA.
Environ Sci Technol. 2009 Feb 1;43(3):764-8. doi: 10.1021/es801655p.
Microscopic organisms in aquatic environments are continuously exposed to a variety of physical and chemical conditions. Traditionally, it is accepted that due to their small size the physiology of microscopic organisms is not affected by the moving fluid at their scale. In this study, we demonstrate that the small-scale turbulence significantly modulates algal and bacterial nutrient uptake and growth in comparison to still-water control. The rate of energy dissipation emerges as a physically based scaling parameter integrating turbulence across a range of scales and microscopic organism responses at the cell level. Microbiological laboratory tests and bioassays do not consider fluid motion as an important variable in quantifying the physiological responses of microorganisms. A conceptual model of how to integrate the fluid motion in Monod-type kinetics is proposed. We anticipate our findings will encourage researchers to reconsider the laboratory protocols and modeling procedures in the analysis of microorganism physiological responses to changing physical and chemical environments by integrating the effect of turbulence.
水生环境中的微生物不断受到各种物理和化学条件的影响。传统观点认为，由于微生物体积小，其生理机能不受其所处尺度下流动流体的影响。在本研究中，我们证明与静态水对照相比，小尺度湍流显著调节藻类和细菌对养分的摄取及生长。能量耗散率成为一个基于物理的尺度参数，它整合了一系列尺度上的湍流以及细胞水平上微生物的反应。微生物实验室测试和生物测定在量化微生物生理反应时未将流体运动视为重要变量。本文提出了一个如何将流体运动整合到莫诺德型动力学中的概念模型。我们预计，我们的研究结果将促使研究人员在分析微生物对不断变化的物理和化学环境的生理反应时，通过整合湍流的影响，重新考虑实验室方案和建模程序。
