Comparison of glucose fermentation by suspended and gel-entrapped yeast cells: An in vivo nuclear magnetic resonance study

Journal Article · Mon Mar 15 00:00:00 EST 1993 · Biotechnology and Bioengineering; (United States)

DOI:https://doi.org/10.1002/bit.260410607· OSTI ID:6224326

Taipa, M A; Cabral, J M.S. ^[1]; Santos, H ^[2]

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1. Centro de Tecnologia Quimica e Biologica, Oeiras (Portugal) Inst. Superior Tecnico, Lisboa (Portugal)
2. Centro de Tecnologia Quimica e Biologica, Oeiras (Portugal) U.N.L., Monte de Caparica (Portugal)

Phosphorus-31 nuclear magnetic resonance ([sup 31]P NMR) was used to compare the anaerobic metabolism of glucose by suspended and gel-entrapped Saccaromyces bayanus cells. The fermentation of glucose was carried out in a reaction system with continuous circulation through the NMR sample tube. The intracellular pH and the levels of some phosphorylated compounds were noninvasively monitored by [sup 31]P NMR while glucose, fermentation products, and biomass were determined by analytical techniques. Qualitative comparisons showed that no significant differences are observed in the relative concentrations of the major phosphorylated metabolites in the spectra, but distinct profile for the variation of both intracellular and extracellular pH of immobilized cells is maintained at a constant value throughout the fermentation as opposed to freely suspended cells for which a steady decrease in the internal pH occurs. A faster and stronger acidification is also observed in the external medium of the assays with suspended cells. Furthermore, higher yields for ethanol and biomass production and lower yields of fermentation by-products are obtained with immobilized cells. It is concluded that the higher intracellular pH achieved in the presence of the gel matrix had a regulatory effect on the metabolism which favored the ethanol production pathway.

• OSTI ID: 6224326
• Journal Information: Biotechnology and Bioengineering; (United States), Vol. 41:6; ISSN 0006-3592
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
ETHANOL
YIELDS
GLUCOSE
FERMENTATION
SACCHAROMYCES
GROWTH
ANAEROBIC DIGESTION
COMPARATIVE EVALUATIONS
IMMOBILIZED CELLS
IN VIVO
NUCLEAR MAGNETIC RESONANCE
PHOSPHORUS 31
ALCOHOLS
ALDEHYDES
BIOCONVERSION
CARBOHYDRATES
DIGESTION
EUMYCOTA
EVALUATION
FUNGI
HEXOSES
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MANAGEMENT
MICROORGANISMS
MONOSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
PLANTS
PROCESSING
RESONANCE
SACCHARIDES
STABLE ISOTOPES
WASTE MANAGEMENT
WASTE PROCESSING
YEASTS
090900* - Biomass Fuels- Processing- (1990-)