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Ethanol production from starch in a pervaporation membrane bioreactor using Clostridium thermohydrosulfuricum
Author(s) -
Mori Yutaka,
Inaba Toshiharu
Publication year - 1990
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260360815
Subject(s) - bioreactor , pervaporation , membrane , chemistry , fermentation , ethanol , ethanol fuel , chromatography , membrane bioreactor , ethanol fermentation , food science , biochemistry , permeation , organic chemistry
To attain both high productivity and efficient recovery of ethanol from broth, a membrane bioreactor consisting of a jar fermentor and a pervaporation system was applied to the direct production of ethanol from uncooked starch with a thermophilic anaerobic bacterium, Clostridium thermohydrosulfuricum . From four types of ethanol‐selective membranes tested, microporous polytetrafluoroethylene (PTFE) membrane, the pores of which are impregnated with silicone rubber, was chosen for its large flux, high ethanol selectivity, and high stability. During fed‐batch fermentation with pervaporation in the membrane bioreactor, ethanol was continuously extracted and concentrated in two traps with concentrations at 5.6%–6.2% (w/w) in trap 1 (20 °C) and 27%–32% (w/w) in trap 2 (liquid N 2 ), while the ethanol concentration in the broth was maintained at 0.85–0.9% (w/w). Due to the low ethanol concentration in the broth, and the immobilization of bacterial cells by the membrane, the number of viable cells, and, eventually, the ethanol productivity, increased in the membrane bioreactor.