title: Microbial hydrogen production from sweet potato starch residue.
abstract: Clostridium butyricum could produce hydrogen from a sweet potato starch residue upon supplementation of nitrogen sources. A repeated batch culture using a mixed culture of C. butyricum and Enterobacter aerogenes produced hydrogen with a yield of 2.4 mol H2/mol glucose under a controlled culture pH of 5.25 in a medium consisting of the sweet potato starch residue and 0.1% Polypepton without addition of any reducing agents. Rhodobacter sp. M-19 produced hydrogen from the supernatant of the culture broth obtained in the repeated batch culture containing C. butyricum and E. aerogenes when 50 microg/l Na2MoO4.2H2O and 20 mg/l EDTA were added to the supernatant and it was cultured under a controlled culture pH of 7.5. A high yield of hydrogen of 7.0 mol H2/mol glucose from the starch remaining in the starch residue was attained in two-step repeated batch cultures containing C. butyricum and E. aerogenes, and by Rhodobacter sp. M-19.
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Miyazaki University, 1-1 Nishi, Gakuen-kibanadai, Miyazaki 889-2192, Japan. yokoi@cc.miyazaki-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Yokoi
authors.forename: A
authors.initials: A
authors.lastname: Saitsu
authors.forename: H
authors.initials: H
authors.lastname: Uchida
authors.forename: J
authors.initials: J
authors.lastname: Hirose
authors.forename: S
authors.initials: S
authors.lastname: Hayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Takasaki