Associate Professor, Department of Agricultural and Biological Engineering
The Pennsylvania State University
One way of increasing productivity during fermentation is to increase biomass concentration in the biorectors. This becomes even more critical during continuous fermentations due to wash out at high dilutions rates. The uses of immobilized-cell, hollow-fiber and cell-recycled fermenters are limited because of high start-up cost and membrane fouling during the fermentation. Biofilms, consisting of the natural attachment of microorganisms to an inert support, are a natural form of cell immobilization. Biofilm reactors have been evaluated for biofuel productions, mainly ethanol, in order to overcome cell washout and low productivity in repeated batch or continuous fermentation. Plastic Composite Support (PCS), consisting of polypropylene with up to 50% w/w of various agricultural materials as packed-bed reactor for ethanol production. Overall, PCS biofilm reactors demonstrated up to ten times higher ethanol production rates comparing to suspension cell cultures or polypropylene-alone support (PPS) control.