The detection and characterization of bacterial food pathogens from homogenates of meats and vegetables will benefit from methods that accelerate their concentration and recovery. We report an approach based on hollow fiber membrane microfiltration that enables small volumes of viable bacteria to be rapidly concentrated from a large volume of food extract. The resulting sample is in a form amenable to probing for presence of pathogens using PCR or antibody reagents. However, fouling at the membrane surface must be addressed since the bacteria are present in a background of proteins, colloidal particles, and macromolecules which can accumulate within, or at the surface, of the membrane pores. Otherwise, this becomes a major impediment to achieving sustainable fluxes across membranes even though the porosity, equivalent to a 0.2 to 0.45 micrometer cutoff, is relatively large. This paper presents a bioprocess model of microfluidic transport that describes transmembrane pressure, flux, and depositionof a fouling layer as a function of distance from the entrance of a hollow fiber membrane during crossflow filtration of aqueous protein homogenates. Applications of the model in identifying optima for the membrane’s geometric configuration will be discussed in the context of an approach that combines enzyme pretreatment of the initial sample followed by pre-filtration and crossflow microfiltration. The model identifies conditions that control membrane fouling so that efficient and reproducible concentration and recovery of bacterial cells in a viable form is acheived. Wider application of this model to microfiltration of other biological media will also be presented.<br/>

Bioprocess modeling of fouling phenomena in cross-flow microfiltration of viable bacteria

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.