title: Inhibition effect of secondary metabolites accumulated in a pervaporation membrane bioreactor on ethanol fermentation of Saccharomyces cerevisiae.
abstract: The secondary metabolites accumulated in a pervaporation membrane bioreactor during ethanol fermentation were mostly composed of acetic acid, lactic acid, propionic acid, citric acid, succinic acid and glycerol. The inhibition effect of these compounds at a broad concentration range was studied through ethanol fermentation by Saccharomyces cerevisiae. An increasing concentration of the secondary metabolites led to longer lag time and a reduction of cell growth. The specific cell growth rate, cell yield, ethanol productivity were only 0.061 h(-1), 0.024, 0.47 g L(-1) h(-1) respectively, when the medium contained 3.12 g of acetic acid, 10.23 g of lactic acid, 2.72 g of propionic acid, 1.35 g of citric acid, 2.26 g of succinic acid and 49.25 g of glycerol per liter (a concentration level in pervaporation membrane bioreactor at later fermentation period). By increasing pH of the medium to 6.0-8.0, the inhibition of these secondary metabolites could be greatly relieved.
authors.affiliation: School of Chemical Engineering, Sichuan University, 610065 Chengdu, China.
authors.forename: Senqing
authors.initials: S
authors.lastname: Fan
authors.affiliation: School of Chemical Engineering, Sichuan University, 610065 Chengdu, China. Electronic address: mgch@scu.edu.cn.
authors.forename: Zeyi
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: Biogas Institute of Ministry of Agriculture, 610041 Chengdu, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Tang
authors.affiliation: College of Chemistry and Chemical Engineering, Southwest Petroleum University, 610500 Chengdu, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Chen
authors.affiliation: School of Chemical Engineering, Sichuan University, 610065 Chengdu, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Chemical Engineering, Sichuan University, 610065 Chengdu, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Deng
authors.affiliation: School of Chemical Engineering, Sichuan University, 610065 Chengdu, China.
authors.forename: Peina
authors.initials: P
authors.lastname: Yao
authors.affiliation: School of Chemical Engineering, Sichuan University, 610065 Chengdu, China.
authors.forename: Weijia
authors.initials: W
authors.lastname: Li
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D064210:Secondary Metabolism; D013997:Time Factors; D014835:Volatilization
chemical_list: D008567:Membranes, Artificial; D000431:Ethanol
keywords: Ethanol fermentation; Inhibition effect; Pervaporation membrane bioreactor; Saccharomyces cerevisiae; Secondary metabolites