Microfluidic bioanalytical flow cells for biofilm studies: a review

Abstract

A comprehensive review of the current state of microfluidic bioanalytical research applied to bacterial biofilms.

A Generalized Kinetic Framework Applied to Whole‐Cell Bioelectrocatalysis in Bioflow Reactors Clarifies Performance Enhancements for Geobacter Sulfurreducens Biofilms

“…Microfluidic channels can address this problem because dead space is nearly zero. Combined with strictly laminar flow, microfluidic bioreactors also offer precise control of the shear forces and of diffusion barriers at the biofilm‐liquid interface . High surface‐area‐to‐volume ratios result in efficient diffusive mass‐transfer between the nutrient solution and the wall‐adhered biofilm, even for short contact times at high flow velocities .…”

“…Due to the small volumes used in microfluidic bioreactors, liquid consumption is reduced, thus long‐duration studies are possible under a large range of hydrodynamic conditions without the need for frequent refilling of reagent sources. With the proliferation of microfluidic bioanalytical tools for real‐time in situ measurements of biofilms and their by‐products, deeper scientific investigations are possible with better accuracy and repeatability . In this work, we use microfluidic electrochemical reactor to study whole‐cell biofilm electrocatalysis of Geobacter sulfurreducens biofilm under flow.…”

“…S2 in SI) from surface‐adhered cells or their biofilms should be measured while accurate control over flow rate and [S] are applied. An electroactive biofilm (EAB) from electrogenic bacteria, such as Geobacter sulfurreducens is an excellent choice because its ability to transfer electrons to an electrode during respiration,, enabling direct observations of instantaneous turnover rate using chronoamperometric measurements of electric current. For a pure culture EAB of G. sulfurreducens under anaerobic conditions, the turnover rate of an acetate substrate (Ac), namely (mol Ac s −1 ), is calculated from the electrical current I (C s −1 ) using Eq.…”

“…Combined with strictly laminar flow, microfluidic bioreactors also offer precise control of the shear forces and of diffusion barriers at the biofilm-liquid interface. [14] High surface-area-to-volume ratios result in efficient diffusive mass-transfer between the nutrient solution and the walladhered biofilm, even for short contact times at high flow velocities. [15] Due to the small volumes used in microfluidic bioreactors, liquid consumption is reduced, thus long-duration studies are possible under a large range of hydrodynamic conditions without the need for frequent refilling of reagent sources.…”

“…With the proliferation of microfluidic bioanalytical tools for real-time in situ measurements of biofilms and their byproducts, deeper scientific investigations are possible with better accuracy and repeatability. [14] In this work, we use microfluidic electrochemical reactor to study whole-cell biofilm electrocatalysis of Geobacter sulfurreducens biofilm under flow. The kinetic framework used connects whole-cell catalysis in flow systems to traditional Michaelis-Menten kinetics (Eq.…”