title: Strategies for production of butanol and butyl-butyrate through lipase-catalyzed esterification.
abstract: In this study, a fermentation process for production of butanol and butyl-butyrate by using Clostridium sp. strain BOH3 is developed. This strain is able to produce butyric acid and butanol when it ferments 60 g/L xylose. Meanwhile, it also excreted indigenous lipases (induced by olive oil) which naturally convert butyric acid and butanol into 1.2 g/L of butyl-butyrate. When Bio-OSR was used as both an inducer for lipase and extractant for butyl-butyrate, the butyl-butyrate concentration can reach 6.3 g/L. To further increase the yield, additional lipases and butyric acid are added to the fermentation system. Moreover, kerosene was used as an extractant to remove butyl-butyrate in situ. When all strategies are combined, 22.4 g/L butyl-butyrate can be produced in a fed-batch reactor spiked with 70 g/L xylose and 7.9 g/L butyric acid, which is 4.5-fold of that in a similar system (5 g/L) with hexadecane as the extractant.
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Fengxue
authors.initials: F
authors.lastname: Xin
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Anindya
authors.initials: A
authors.lastname: Basu
authors.affiliation: Department of Chemical and Bimolecular Engineering, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Kun-Lin
authors.initials: KL
authors.lastname: Yang
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576, Singapore. Electronic address: jianzhong.he@nus.edu.sg.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: He
mesh_terms: D020001:1-Butanol / Q000378:metabolism; D019149:Bioreactors; D000440:Butanols / Q000378:metabolism*; D002087:Butyrates / Q000378:metabolism*; D020148:Butyric Acid / Q000378:metabolism; D002384:Catalysis; D003013:Clostridium / Q000378:metabolism; D004951:Esterification; D005285:Fermentation; D008049:Lipase / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism
chemical_list: D000440:Butanols; D002087:Butyrates; D020148:Butyric Acid; C022793:n-butyl n-butyrate; D020001:1-Butanol; D014994:Xylose; D008049:Lipase
keywords: Butanol; Butyl-butyrate; Clostridium; Extractant; Lipase