Immobilization of yeast cells in PVA particles for beer fermentation

In this study, the potential of application of non-aggressive LentiKat® technique for brewer's yeast immobilization on polyvinyl alcohol was assessed. High cell loads of about 109 cells/ml were achieved by this procedure and immobilization procedure had no adverse effect on cell viability. The stability and activity of obtained immobilized biocatalyst was tested in the growth studies and fermentations. Immobilized cells exhibited high fermentation activity in both, laboratory and pilot-scale fermentations. In three successive gas-lift reactor fermentations the apparent attenuation of around 80% was reached after only 2 days, indicating good potential of immobilized cells for development of continuous primary beer fermentation. LentiKat® particles showed high mechanical and fermentative stability, since they endured 30 days of operating time during 6-month period without significant change of cell activity, particle shape and particle size.