Simultaneous saccharification and extractive fermentation of cellulosic substrates

Alcohol fermentation has traditionally been carried out in aqueous environments because of the ready solubility of reactant (sugar) and product (ethanol). However, extraction of the product ethanol into a nonmiscible phase can result in kinetic benefits due to reduced inhibition of the fermentation reactions. In this study, we report the development of a novel simultaneous saccharification and extractive fermentation (SSEF) process. Ethanol productivity was increased by up to 65% over conventional (nonextractive) fed‐batch simultaneous saccharification systems when calculated on the basis of aqueous phase volume. The amount of water required for SSEF reactions was dramatically reduced from that required for conventional SSF. In batch SSEF reactors with 2.5% aqueous phase, 50% conversion of 25% (aqueous phase concentration) Solka Floc could be achieved in 48 h using 2 FPU/g cellulase. © 1996 John Wiley & Sons, Inc.

[1]  M. Coughlan.  Enzymic hydrolysis of cellulose: An overview , 1992 .

[2]  Tracy E Casavant,et al.  Effect of surfactant and particle size reduction on hydrolysis of deinking sludge and nonrecyclable newsprint , 1995, Biotechnology and bioengineering.

[3]  L. Ingram,et al.  Conversion of cellulosic materials to ethanol , 1995 .

[4]  Andrew J. Daugulis,et al.  Screening and identification of extractive fermentation solvents using a database , 1985 .

[5]  G. L. Miller.  Use of Dinitrosalicylic Acid Reagent for Determination of Reducing Sugar , 1959 .

[6]  M Tanaka,et al.  A model of enzyme adsorption and hydrolysis of microcrystalline cellulose with slow deactivation of the adsorbed enzyme , 1988, Biotechnology and bioengineering.

[7]  S J Duff,et al.  Effect of surfactants on cellulose hydrolysis , 1993, Biotechnology and bioengineering.

[8]  Michael R. Ladisch,et al.  Ethanol production and the cost of fermentable sugars from biomass , 1991 .

[9]  Lee R. Lynd,et al.  Analysis of conversion of particulate biomass to ethanol in continuous solids retaining and cascade bioreactors , 1994 .

[10]  Charles E. Wyman,et al.  Ethanol from lignocellulosic biomass: Technology, economics, and opportunities , 1994 .

[11]  K. Eriksson,et al.  Production of ethanol from lignocellulosic materials: State of the art , 1990 .

[12]  S. Duff,et al.  Simultaneous hydrolysis and fermentation of pulp mill primary clarifier sludge , 1994 .

[13]  C. Wyman,et al.  Study of the enzymatic hydrolysis of cellulose for production of fuel ethanol by the simultaneous saccharification and fermentation process , 1993, Biotechnology and bioengineering.

[14]  A. Daugulis,et al.  Solvent Selection Strategies for Extractive Biocatalysis , 1991, Biotechnology progress.

[15]  P. McLellan,et al.  The economics of ethanol production by extractive fermentation , 1991 .