Very high ethanol productivity in an innovative continuous two-stage bioreactor with cell recycle

The performance of an innovative two-stage continuous bioreactor with cell recycle—potentially capable of giving very high ethanol productivity—was investigated. The first stage was dedicated to cell growth, whereas the second stage was dedicated to ethanol production. A high cell density was obtained by an ultrafiltration module coupled to the outlet of the second reactor. A recycle loop from the second stage to the first one was tested to improve cell viability and activity. Cultivations of Saccharomyces cerevisiae in mineral medium on glucose were performed at 30°C and pH 4. At steady state, total biomass concentrations of 59 and 157 gDCW l−1 and ethanol concentrations of 31 and 65 g l−1 were obtained in the first and second stage, respectively. The residual glucose concentration was 73 g l−1 in the first stage and close to zero in the second stage. The present study shows that a very high ethanol productivity (up to 41 g l−1 h−1) can indeed be obtained with complete conversion of the glucose and with a high ethanol titre (8.3°GL) in the two-stage system.

[1]  Siddhartha Datta,et al.  Analysis of the performance of a continuous membrane bioreactor with cell recycling during ethanol fermentation , 1998 .

[2]  K. Ogawa,et al.  Enhanced glycerol production in Shochu yeast by heat-shock treatment is due to prolonged transcription of GPD1. , 2000, Journal of bioscience and bioengineering.

[3]  G. Goma,et al.  Improving ethanol production and viability of Saccharomyces cerevisiae by a vitamin feeding strategy during fed-batch process , 2002, Applied Microbiology and Biotechnology.

[4]  Johannes P. van Dijken,et al.  Redox balances in the metabolism of sugars by yeasts (NAD(H); NADP(H); glucose metabolism; xylose fermentation; ethanol; Crabtree effect; Custers effect) , 1986 .

[5]  Mohammad J. Taherzadeh,et al.  Acetic acid—friend or foe in anaerobic batch conversion of glucose to ethanol by Saccharomyces cerevisiae? , 1997 .

[6]  I. Dunn,et al.  ANALYSIS OF A TWO-STAGE FERMENTOR WITH RECYCLE FOR CONTINUOUS ETHANOL PRODUCTION , 1998 .

[7]  J. Nielsen,et al.  Anaerobic and aerobic batch cultivations of Saccharomyces cerevisiae mutants impaired in glycerol synthesis , 2000, Yeast.

[8]  L. Adler,et al.  Osmoregulation in Saccharomyces cerevisiae Studies on the osmotic induction of glycerol production and glycerol 3‐phosphate dehydrogenase (NAD+) , 1991, FEBS letters.

[9]  G. Goma,et al.  Aeration strategy: a need for very high ethanol performance in Saccharomyces cerevisiae fed-batch process , 2004, Applied Microbiology and Biotechnology.

[10]  H. Monbouquette,et al.  Models for high cell density bioreactors must consider biomass volume fraction: Cell recycle example , 1987, Biotechnology and bioengineering.

[11]  S. Alfenore,et al.  Synergistic temperature and ethanol effect on Saccharomyces cerevisiae dynamic behaviour in ethanol bio-fuel production , 2004, Bioprocess and biosystems engineering.

[12]  G. Goma,et al.  Modeling of ethanol fermentation at high yeast concentrations. , 1989, Biotechnology and bioengineering.

[13]  C. Shin,et al.  Performance, kinetics, and substrate utilization in a continuous yeast fermentation with cell recycle by ultrafiltration membranes , 2004, Applied Microbiology and Biotechnology.

[14]  H. Chang,et al.  Kinetics of ethanol fermentations in membrane cell recycle fermentors , 1987, Biotechnology and bioengineering.

[15]  G. Goma,et al.  High yeast concentration in continuous fermentation with cell recycle obtained by tangential microfiltration , 1987, Biotechnology Letters.

[16]  T. Egli,et al.  Theoretical Analysis of Media Used in the Growth of Yeasts on Methanol , 1981 .

[17]  J. A. Roels,et al.  Energetics and Kinetics in Biotechnology , 1983 .

[18]  E. Marra,et al.  Acid stress adaptation protects Saccharomyces cerevisiae from acetic acid-induced programmed cell death. , 2005, Gene.

[19]  H. Monbouquette,et al.  Modeling high‐biomass‐density cell recycle fermentors , 1992, Biotechnology and bioengineering.

[20]  Gerhard K Hoppe,et al.  The effect of micro-aerobic conditions on continuous ethanol production by Saccharomyces cerevisiae , 1984, Biotechnology Letters.

[21]  E. Nevoigt,et al.  Osmoregulation and glycerol metabolism in the yeast Saccharomyces cerevisiae. , 1997, FEMS microbiology reviews.

[22]  M. Shimoda,et al.  Enhancement of glycerol production by brewing yeast (Saccharomyces cerevisiae) with heat shock treatment , 1996 .

[23]  Barbara M. Bakker,et al.  Stoichiometry and compartmentation of NADH metabolism in Saccharomyces cerevisiae. , 2001, FEMS microbiology reviews.

[24]  K. Luyben,et al.  Kinetics of ethanol production by baker's yeast in an integrated process of fermentation and microfiltration , 1992 .

[25]  P. Barré,et al.  Glycerol Overproduction by Engineered Saccharomyces cerevisiae Wine Yeast Strains Leads to Substantial Changes in By-Product Formation and to a Stimulation of Fermentation Rate in Stationary Phase , 1999, Applied and Environmental Microbiology.

[26]  I. Dunn,et al.  Analysis of the performance of a two-stage fermentor with cell recycle for continuous ethanol production using different kinetic models , 1999 .

[27]  Gunnar Lidén,et al.  Engineering of the metabolism of Saccharomyces cerevisiae for anaerobic production of mannitol. , 2003, FEMS yeast research.

[28]  M. Loureiro-Dias,et al.  Weak acid inhibition of fermentation by Zygosaccharomyces bailii and Saccharomyces cerevisiae. , 1997, International journal of food microbiology.

[29]  G Stephanopoulos,et al.  Physiological, biochemical, and mathematical studies of micro‐aerobic continuous ethanol fermentation by Saccharomyces cerevisiae. I: Hysteresis, oscillations, and maximum specific ethanol productivities in chemostat culture , 1990, Biotechnology and bioengineering.

[30]  M. Bagby,et al.  Bioconversion of wheat straw cellulose/hemicellulose to ethanol by Saccharomyces uvarum and Pachysolen tannophilus , 1982, Biotechnology and bioengineering.

[31]  J. Uribelarrea,et al.  Inhibition and growth factor deficiencies in alcoholic fermentation bySaccharomyces cerevisiae , 1989, Current Microbiology.

[32]  H. Chang,et al.  Long-term operation of continuous high cell density culture of Saccharomyces cerevisiae with membrane filtration and on-line cell concentration monitoring , 1999 .

[33]  R Maciel,et al.  Kinetics of ethanol fermentation with high biomass concentration considering the effect of temperature , 2001, Applied biochemistry and biotechnology.

[34]  M. T. Silva,et al.  Saccharomyces cerevisiae commits to a programmed cell death process in response to acetic acid. , 2001, Microbiology.