Ethanol production in immobilized-cell bioreactors from mixed sugar syrups and enzymatic hydrolysates of steam-exploded biomass

We investigated ethanol production from mixed sugar syrups. Hydrolysates were prepared from enzymatic saccharification of steam-pretreated aspen chips. Syrups containing 45 g/L of glucose and 12 g/L of xylose were detoxified through two ion-exchange resins and then fermented with Pichia stipitis and...

Full description

Saved in:
Bibliographic Details
Published in:Applied biochemistry and biotechnology 2004, Vol.113 (1-3), p.539-557
Main Authors: De Bari, I, Cuna, D, Nanna, F, Braccio, G
Format: Article
Language:English
Subjects:
Alginates
Alginates - chemistry
Alginic acid
Anions
Beads
Biomass
Bioreactors
Biotechnology - methods
Calcium - chemistry
Carbohydrates
Cations
Cells, Immobilized - chemistry
Chromatography, Ion Exchange
Enzymes
Ethanol
Ethanol - chemistry
ethanol production
Fermentation
Glucose - chemistry
Hydrolysates
Hydrolysis
immobilized cells
Ion exchange
Ion exchange resins
Ion Exchange Resins - chemistry
Oxygen - metabolism
Oxygenation
Pichia - metabolism
Pichia stipitis
Protein Hydrolysates - chemistry
Resins
Saccharification
Saccharomyces cerevisiae
Saccharomyces cerevisiae - metabolism
Steam
Studies
Sugar
Syrups
Temperature
Time Factors
Xylose - chemistry
Yeast
Yeasts
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We investigated ethanol production from mixed sugar syrups. Hydrolysates were prepared from enzymatic saccharification of steam-pretreated aspen chips. Syrups containing 45 g/L of glucose and 12 g/L of xylose were detoxified through two ion-exchange resins and then fermented with Pichia stipitis and Saccharomyces cerevisiae immobilized in Ca-alginate gel beads. Combinations of different gel fractions in the fermentation volume, amount of yeast cells, and ratios of P. stipitis vs S. cerevisiae within each bead were compared. In the best conditions, by using a total beads volume corresponding to 25% of the working volume, we obtained a yield of 0.39 g(ethanol)/g(initial sugars). This amount of gel entrapped an initial cell concentration of 6 x 1012cells/L with ratio of S. cerevisiae/P. stipitis of 0.25 g/g. Modified stirred-tank reactors were obtained either by adding marbles or by inserting a perforated metal cylinder, which reduced considerably the rupture of beads while visibly improving oxygenation of the medium.
ISSN:0273-2289
1559-0291
0273-2289
DOI:10.1385/abab:114:1-3:539