Abstract: This paper carried on ethanol fermentation by immobilized cell with PVA(polyvinyl alcohol) carrier by either freezing or crosslinking with H3BO3. The results showed that the carrier prepared by freezing method owns stable capability when carried through numerous fermentation and the highest ethanol concentration can achieve 8.37%, realizing re-fermentation and cost reduction greatly. The carrier prepared by crosslinking with H3BO3 has better effect on one batch fermentation, while the ethanol concentration can achieve 8.26%, with residue sugar 0.18%, but the carrier becomes metamorphosed seriously, so it is not suitable for re-fermentation.

Key words: polyvinyl alcohol, immobilized yeast, ethanol fermentation