Deshpande P A, Shonnard D R
Department of Chemical Engineering, Michigan Technological University, Houghton, Michigan 49931, USA.
Appl Environ Microbiol. 2000 Feb;66(2):763-8. doi: 10.1128/AEM.66.2.763-768.2000.
This study reports an improved spectrophotometric method for studying bacterial (Pseudomonas fluorescens UPER-1) transport and attachment in saturated porous media (silica sand). While studying the effect of ionic strength by the traditional packed-column spectrophotometric method, we encountered an artifact. The absorbance of a well-stirred bacterial suspension was found to decrease with time in the presence of high concentrations of sodium and potassium phosphate salts (> or = 10(-2) M) as the cells continued to age in a resting stage. Our results show that collision efficiency and a bed ripening index will be in error by as much as 20% if breakthrough is measured by the traditional spectrophotometric technique. We present an improved experimental technique that will minimize the artifact and should substantially advance the understanding of bacteria transport in porous media.
本研究报告了一种改进的分光光度法，用于研究细菌（荧光假单胞菌UPER-1）在饱和多孔介质（硅砂）中的传输和附着。在用传统填充柱分光光度法研究离子强度的影响时，我们遇到了一个假象。当细胞在静止阶段持续老化时，发现在高浓度的磷酸钠和钾盐（≥10⁻² M）存在下，充分搅拌的细菌悬浮液的吸光度会随时间降低。我们的结果表明，如果用传统分光光度技术测量穿透率，碰撞效率和床层成熟指数将出现高达20%的误差。我们提出了一种改进的实验技术，该技术将使这种假象最小化，并应能大大推进对细菌在多孔介质中传输的理解。
