(490ad) Effects of Polyvinyl Alcohol and Surfactants On the Enzymatic Hydrolyis of Alkali-Treated Waste Newsprint

Effects of Polyvinyl alcohol (PVA) and surfactants on the enzymatic hydrolyis of waste newsprint papers were investigated. The enzymatic digestibility glucan in the feedstock pretreated by sodium hydroxide was in the vicinity of 60% with 15 FPU loading of Spezyme CP and 30 CBU β-glucosidase. In order to improve the enzymatic digestibility, PVA and surfactants were supplemented during the hydrolysis reaction. With PVA and non-ionic surfactants addition, the cellulose enzymatic digestibility was increased to 70 -80%. PVA and non-ionic surfactants were found to reduce unspecific adsorption of the enzyme on the substrate. The treated feedstocks were tested as substrate for production of ethanol through simultaneous saccharification and fermentation (SSF) using the cellulase and Saccharomyces cerevisiae, NRE- D5A. The SSF proceeded without any major difficulties with application of PVA and Tween -80. The observed ethanol yields were in the range of 70-80% of theoretical maximum. Addition of Triton X-100 (a non-ionic surfactant) improved the enzymatic hydrolysis, but has shown a negative effect on the fermentation process. Data on the effects of additional surfactants on hydrolysis and fermentation are reported.