Abstract
Shewanella oneidensis is a metal reducing bacterium, which is
of interest for bioremediation and clean energy applications. S.
oneidensis biofilms play a critical role in several situations such
as in microbial energy harvesting devices. Here, we use a
microfluidic device to quantify the effects of hydrodynamics on
the biofilm morphology of S. oneidensis. For different rates of
fluid flow through a complex microfluidic device, we studied
the spatiotemporal dynamics of biofilms, and we quantified
several morphological features such as spatial distribution,
cluster formation and surface coverage. We found that
hydrodynamics resulted in significant differences in biofilm
dynamics. The baffles in the device created regions of low and
high flow in the same device. At higher flow rates, a nonuniform
biofilm develops, due to unequal advection in different
regions of the microchannel. However, at lower flow rates, a
more uniform biofilm evolved. This depicts competition
between adhesion events, growth and fluid advection. Atomic
force microscopy (AFM) revealed that higher production of
extra-cellular polymeric substances (EPS) occurred at higher
flow velocities.
