High productivity bioethanol fermentation by immobilizedSaccharomyces bayanusonto carboxymethylcellulose-g- poly(N-vinyl-2-pyrrolidone) beads

Abstract

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.

125thAnniversary Review: Developments in brewing and distilling yeast strains

“…Fermentation using an immobilized cell system, compared with a free cell system, offers a number of advantages such as protection of cells from the build‐up of toxic metabolites (such as ethanol), potential for reuse, lower operating costs (no centrifugation or filtration required) and high volumetric productivity. A number of support materials have been utilized for bioethanol fermentation using immobilized microorganisms with cell entrapment within hydrogel polymers, especially calcium alginate gels, which have been the most widely studied . Final ethanol concentrations of as high 13.6% can be tolerated by immobilized yeast and they can be reused seven or eight times .…”

Bioethanol Production from Oil Palm Empty Fruit Bunches Using Saccharomyces cerevisiae Immobilized on Sodium Alginate Beads

“…Usually, commercial-scale bioethanol production from glucose employs an anaerobic fermentation process involving yeasts, which mainly Saccharomyces cerevisiae [4,5], Saccharomyces bayanus [6], Saccharomyces pastorianus [7], and Kluyveromyces marxianus [8]. Glucose as a substrate for bioethanol preparation can be derived from agricultural waste such as oil palm empty fruit bunch (OPEFB) through enzymatic saccharification although this process requires a long reaction time of about 24 to 72 hours [9,10].…”