Microscale confinement features can affect biofilm formation
- 1.4k Downloads
The majority of bacteria in nature live in biofilms, where they are encased by extracellular polymeric substances (EPS) and adhere to various surfaces and interfaces. Investigating the process of biofilm formation is critical for advancing our understanding of microbes in their most common mode of living. Despite progress in characterizing the effect of various environmental factors on biofilm formation, work remains to be done in the realm of exploring the inter-relationship between hydrodynamics, microbial adhesion and biofilm growth. We investigate the impact of secondary flow structures, which are created due to semi-confined features in a microfluidic device, on biofilm formation of Shewanella oneidensis MR-1. Secondary flows are important in many natural and artificial systems, but few studies have investigated their role in biofilm formation. To direct secondary flows in the creeping flow regime, where the Reynolds number is low, we flow microbe-laden culture through microscale confinement features. We demonstrate that these confinement features can result in pronounced changes in biofilm dynamics as a function of the fluid flow rate.
KeywordsMicrofluidics Biofilms Secondary flows Bacteria Micro-vortices
The authors would like to thank Dr. Alfred Spormann at Stanford University for providing the bacterial strains. A. Kumar performed the work as a Eugene P. Wigner Fellow at the Oak Ridge National Laboratory (ORNL). A portion of this research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at ORNL by the Scientific User Facilities Division, US Department of Energy (US DOE). The authors acknowledge research support from the US DOE Office of Biological and Environmental Sciences. ORNL is managed by UT-Battelle, LLC, for the US DOE under contract no. DEAC05-00OR22725. The authors also acknowledge the Natural Sciences and Engineering Research Council of Canada for providing NSERC fellowship to Dr. Neethirajan.
Supplementary Video 1: This video depicts the backward flow in the channel. The fluid is seeded with 500 nm fluorescent polystyrene particles. The higher magnification images clearly show the vortex structure (MPG 5378 kb)
- Neethirajan S, Karig D, Kumar A, Mukherjee PP, Retterer S, Doktycz M (2012) Biofilms in microfluidic devices. In: Bhushan B (ed) Encylopedia of nanotechnology. Springer, New YorkGoogle Scholar