High productivity bioethanol fermentation by immobilized Saccharomyces bayanus onto carboxymethylcellulose-g-poly(N-vinyl-2-pyrrolidone) beads

Crosslinked graft copolymers of CMC with N-vinyl-2-pyrrolidone (N-VP) were prepared in different grafting yields. Saccharomyces bayanus was immobilized in the graft copolymers of carboxymethylcellulose-g-poly(N-vinyl-2-pyrrolidone) (CMC-g-PVP) for ethanol fermentation. The effects of grafting yield, initial glucose concentration, and crosslinker concentration on the yield of ethanol process was investigated. Ethanol production increased when percentage of N-vinyl-2-pyrrolidone in the graft copolymer was increased. The maximum concentration, productivity, and yield of ethanol were 98.78 g L-1, 8.23 g L-1 h(-1) and 0.494 g g(-1), respectively. Reusability of the immobilized yeasts was found that the materials can be used seven times without losing their activity.