The use of immobilized cells is an effective method for increasing cell mass concentration in bioreactor and improving the efficiency of substrate utilization and productivities of fermentation processes with minimum of the production costs (Santos et al., 2008).
The most commonly used whole cells immobilization techniques can be artificial, such as incorporation within a porous polymer matrices and containment behind a microporous barrier, or natural, such as cells self aggregation and cells attachment onto the surface of insoluble carrier (Öztop et al., 2003).
The main drawbacks of polymer incorporated yeast for commercial scale operations are: high immobilization cost, low physical strength of beads; substrate and product diffusion limitation; high contamination risk; shorter yeast half-life and impossibility of cells reuse.