Alternating current electrophoretic deposition of Saccharomyces cerevisiae cells and the viability of the deposited biofilm in ethanol production

In this work, we have explored the possibility of using asymmetrical alternating current electrophoretic deposition (AC-EPD) process, which we have previously reported for enzyme deposition, to immobilize Saccharomyces cerevisiae (S. cerevisiae) cells onto stainless steel substrates. The deposition of S. cerevisiae cells at 30 Hz and 200 V(p-p) permits the formation of 89 +/- 16 mu m thick cell layers in 30 min. The mass of the deposited cells is shown to increase quasi-linearly with the deposition time and the applied amplitude. In order to increase the mechanical stability of the immobilized cells, a thin layer of polyurethane was applied after the AC-EPD of S. cerevisiae cells. The viability of the immobilized cells was tested in the production of ethanol. The results showed that the fermentation process with the immobilized S. cerevisiae cells is more efficient than the fermentation carried out with similarly treated free cells. (C) 2010 Elsevier Ltd. All rights reserved.