Environmental effects on growth and ethanol fermentation of immobilized Kluyveromyces fragilis

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5658370

Chen, C

A trickle flow, short column reactor system using a natural sponge as a carrier was used to study the response of the immobilized yeast, Kluyveromyces fragilis NRRL 2415, to environmental and nutritional factors. The specific growth rate of adsorbed K. fragilis using a complete medium as feed during the start-up period was 0.0152 hr{sup {minus}1} which was much lower than 0.60 hr{sup {minus}1}, the value for free cells. The transient responses of immobilized cells to changes in lactose concentration and temperature were quick, reaching new steady state values within half an hour. There was little or no detectable CO{sub 2} evolved if the lactose concentration was below 3.8 g/l. The immobilized K. fragilis did not perform well at temperatures over 40{degree}C, although free cells maintained their viability at 40{degree}C. The inhibitory effect of added ethanol on immobilized K. fragilis was a nonlinear relationship. The thermotolerance of K. fragilis was significantly reduced by the presence of ethanol. A kinetic model was developed to determine the steady state productivity based upon growth and death rates as a function of temperature and ethanol concentration.

• Research Organization: Purdue Univ., Lafayette, IN (USA)
• OSTI ID: 5658370
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090222* -- Alcohol Fuels-- Preparation from Wastes or Biomass-- (1976-1989)
ALCOHOLS
BIOCONVERSION
CARBOHYDRATES
DISACCHARIDES
ETHANOL
EUMYCOTA
FERMENTATION
FUNGI
GROWTH
HYDROXY COMPOUNDS
IMMOBILIZED CELLS
LACTOSE
MATHEMATICAL MODELS
MICROORGANISMS
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PLANTS
SACCHARIDES
STEADY-STATE CONDITIONS
TEMPERATURE DEPENDENCE
YEASTS
YIELDS