Evaluation of cell recycling in continuous fermentation of enzymatic hydrolysates of spruce with Saccharomyces cerevisiae and on-line monitoring of glucose and ethanol

• Published in: Applied microbiology and biotechnology Vol. 50; no. 5; pp. 545 - 551
• Main Authors: Palmqvist, E, Galbe, M, Hahn-Hagerdal, B
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-11-1998; Springer Nature B.V
• Subjects: Acetic Acid - analysis; Aquaculture; beta-Glucosidase - metabolism; Biofuel production; biofuels; Biological and medical sciences; Biotechnology; Cell growth; Chemical Engineering; Energy; Engineering and Technology; Enzymes; Ethanol; Ethanol - metabolism; ethanol production; Fermentation; Fundamental and applied biological sciences. Psychology; Glucose - metabolism; Growth rate; Hexoses - analysis; Hydrogen-Ion Concentration; Hydrolysis; Industrial applications and implications. Economical aspects; Industrial Biotechnology; Industrial Microbiology; Industriell bioteknik; Kemiteknik; Lignin - metabolism; Picea; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Teknik; Time Factors; Trees; Wood; Yeast; Yeasts; Yeast; Environmental factor; Biofuel; Fungi; Batchwise; Alcoholic fermentation; Gymnospermae; Production; pH; Tree; Ascomycetes; Recycling; Picea; Thallophyta; Microorganism growth; Ethanol; Tolerance; Lignocellulosics; Continuous process; Bioreactor; Microorganism culture; Coniferales; Spermatophyta; Inhibitor; Saccharomyces cerevisiae; Comparative study; Sulfite spent liquor
• ISSN: 0175-7598; 1432-0614; 1432-0614
• DOI: 10.1007/s002530051332

The maximum growth rate of Saccharomyces cerevisiae ATCC 96581, adapted to fermentation of spent sulphite liquor (SSL), was 7 times higher in SSL of hardwood than the maximum growth rate of bakers' yeast. ATCC 96581 was studied in the continuous fermentation of spruce hydrolysate without and with cell recycling. Ethanol productivity by ATCC 96581 in continuous fermentation of an enzymatic hydrolysate of spruce was increased 4.6 times by employing cell recycling. On-line analysis of CO2, glucose and ethanol (using a microdialysis probe) was used to investigate the effect of fermentation pH on cell growth and ethanol production, and to set the dilution rate. Cell growth in the spruce hydrolysates was strongly influenced by fermentation pH. The fermentation was operated in continuous mode for 210 h and a theoretical ethanol yield on fermentable sugars was obtained.