title: Fed-batch cultivation of Mucor indicus in dilute-acid lignocellulosic hydrolyzate for ethanol production.
abstract: Mucor indicus fermented dilute-acid lignocellulosic hydrolyzates to ethanol in fed-batch cultivation with complete hexose utilization and partial uptake of xylose. The fungus was tolerant to the inhibitors present in the hydrolyzates. It grew in media containing furfural (1 g/l), hydroxymethylfurfural (1 g/l), vanillin (1 g/l), or acetic acid (7 g/l), but did not germinate directly in the hydrolyzate. However, with fed-batch methodology, after initial growth of M. indicus in 500 ml enzymatic wheat hydrolyzate, lignocellulosic hydrolyzate was fermented with feeding rates 55 and 100 ml/h. The fungus consumed more than 46% of the initial xylose, while less than half of this xylose was excreted in the form of xylitol. The ethanol yield was 0.43 g/g total consumed sugar, and reached the maximum concentration of 19.6 g ethanol/l at the end of feeding phase. Filamentous growth, which is regarded as the main obstacle to large-scale cultivation of M. indicus, was avoided in the fed-batch experiments.
authors.affiliation: Department of Chemical Engineering and Environmental Science, Chalmers University of Technology, 412 96, Göteborg, Sweden.
authors.forename: Keikhosro
authors.initials: K
authors.lastname: Karimi
authors.forename: Tomas
authors.initials: T
authors.lastname: Brandberg
authors.forename: Lars
authors.initials: L
authors.lastname: Edebo
authors.forename: Mohammad J
authors.initials: MJ
authors.lastname: Taherzadeh
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D001547:Benzaldehydes / Q000494:pharmacology; D018533:Biomass; D002482:Cellulose / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000494:pharmacology; D005690:Galactose / Q000378:metabolism; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism*; D008358:Mannose / Q000378:metabolism; D009089:Mucor / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D009172:Mycology / Q000379:methods*; D013997:Time Factors; D014993:Xylitol / Q000378:metabolism; D014994:Xylose / Q000378:metabolism
chemical_list: D001547:Benzaldehydes; D000431:Ethanol; C008046:5-hydroxymethylfurfural; D002482:Cellulose; D008031:Lignin; D014994:Xylose; C100058:vanillin; D005662:Furaldehyde; D008358:Mannose; D019342:Acetic Acid; D014993:Xylitol; D005690:Galactose