title: Strategies for reducing supplemental medium cost in bioethanol production from waste house wood hydrolysate by ethanologenic Escherichia coli: inoculum size increase and coculture with Saccharomyces cerevisiae.
abstract: In this paper, we report a simultaneous realization of both efficient ethanol production and saving medium nutrient (corn steep liquor [CSL]) during bioethanol fermentation of overliming-treated hydrolysate of waste house wood (WHW) using ethanologenic Escherichia coli KO11. In cultivation using WHW hydrolysate supplemented with 4% (v/v) CSL and 0.2 g-dry cell weight (DCW)/l E. coli KO11 cells, the overall ethanol yield reached 84% of the theoretical value at 61 h. When we conducted the cultivation with 1% CSL to reduce the supplemental medium cost, the overall ethanol yield remained in the range of 66-72% even at 90 h. We proposed two alternative methods for increasing the overall yield even with 1% CSL. The first method involved increasing the inoculum size of E. coli KO11 up to 0.8 g-DCW/l, where 83% of the overall yield was attained at 60 h of cultivation. The second method involved the coculture of 0.2 g-DCW/l E. coli KO11 together with 0.02 g-DCW/l of Saccharomyces cerevisiae TJ1, and the overall yield reached 81% at 47 h of cultivation.
authors.affiliation: Tsukishima Kikai Co., Ltd., 17-15 Tsukuda 2-Chome, Chuo-ku, Tokyo 104-0051, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Okuda
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ninomiya
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Katakura
authors.forename: Suteaki
authors.initials: S
authors.lastname: Shioya
mesh_terms: D018920:Coculture Techniques / Q000191:economics / Q000379:methods; D017046:Cost Savings / Q000379:methods; D004926:Escherichia coli / Q000378:metabolism*; D000431:Ethanol / Q000191:economics* / Q000378:metabolism*; D006868:Hydrolysis; D007220:Industrial Waste / Q000191:economics* / Q000517:prevention & control; D007564:Japan; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014934:Wood / Q000191:economics* / Q000382:microbiology*
chemical_list: D007220:Industrial Waste; D000431:Ethanol