Microfluidic Concentrator Array for Quantitative Predation Study of Predatory Microbes

Abstract

Despite future impact on the bio-nano-technological application, the study of predatory microbes has been limited due to the complexity associated with co-cultures of prey and predator. In this thesis, to accelerate and simplify the study, we have developed a microfabricated concentrator array device that makes it possible to quantify the predation rate of predator, Bdellovibrio bacteriovorus. Since the concentrator array device can constrain both prey and predator cells within 200 pL chambers at a desired range of cell densities, the predation rates could be quantified indirectly by measuring the time-dependent fluorescent intensity signals from the prey. In addition, we study many different conditions with a single set of cultures because the device can produce a wide range of initial prey to predator density ratios within various concentrator arrays through the use of microfluidic gradient generator structures. We also investigated chemotaxis of B.bacteriovorus strain HD 100 using novel microfluidic concentration gradient generator towards various compounds and prey cell itself. The results were consistent with literatures.