Efficient bioethanol production from paper shredder scrap by a marine derived saccharomyces cerevisiae C-19

The authors paid attention to paper shredder scrap as biomass and studied bioethanol production from them using marine derived yeasts. We reviewed current production methods, suggested the production method that minimized chemical agent use and machinery, and we found out additionally a superiority of paper shredder scrap as a material. As for the saccharification of the material, it was compared sulfuric acid hydrolysis followed by enzymatic saccharification with only the enzymatic one. As a result, the amount of glucose production with the enzymatic saccharification was higher than that with the sulfuric acid followed by the enzymatic one. We found that glucose of 75 g was produced by only the enzymatic saccharification from the paper of 100 g. In this study, the saccharification solution of glucose concentration 270-290 g/L was used by all fermentation tests. About ethanol fermentation, a Saccharomyces cerevisiae C-19 derived from Tokyo Bay was mainly used and both a S. cerevisiae NBRC 10217 and a S. cerevisiae K-7 were used as control strains. As for the fermentation methods, the static fermentation, the agitating fermentation, and the repeated fermentations with immobilized yeasts using the alginate beads were performed. Furthermore, as a new way to increase the amount of total ethanol, ETS (Ethanol Trap System) was developed. By the agitating fermentation, the maximum ethanol concentration of 12 % (w/v) was observed using the strain C-19. In addition, 8.5 % (w/v) of ethanol concentration was produced by the repeated fermentation using immobilized yeast cells. In this study, we discussed both an optimum saccharification condition with enzymes and an optimum fermentation condition for ethanol production using the marine yeast strain C-19. Moreover, these results established that the paper shredder scrap was useful as a novel material for bioethanol production.