Magnesium limitation and its role in apparent toxicity of ethanol during yeast fermentation

Journal Article · Sat Nov 01 04:00:00 EST 1986 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6981074

Dombek, K M; Ingram, L O

The rate of ethanol per milligram of cell protein begins to decline in the early stage of batch fermentation before high concentrations of ethanol have accumulated. In yeast extract-peptone medium (20% glucose), this initial decline appears to be related to growth and to result in part from a nutrient deficiency. The addition of yeast extract, peptone, and ashed preparations of these restored the ability of glucose-reconstituted medium (in which cells had been previously grown) to support vigorous growth. Magnesium was identified as the active component. Supplementing fermentations with 0.5 mM magnesium prolonged exponential growth, resulting in increased yeast cell mass. The addition of magnesium also reduced the decline in fermentative activity (micromoles of CO/sub 2/ evolved per hour per milligram of protein) during the completion of batch fermentations. These two effects reduced the time required for the conversion of 20% glucose into ethanol by 1/3 with no measurable loss in ethanol yield (98% of theoretical maximum yield). It is possible that some of the reported beneficial effects of complex nutrients (soy flour and yeast extract) for ethanol production also result from the correction of a simple inorganic ion deficiency, such as magnesium.

• Research Organization: Univ. of Florida, Gainesville
• OSTI ID: 6981074
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 52:5; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090222* -- Alcohol Fuels-- Preparation from Wastes or Biomass-- (1976-1989)
ALCOHOLS
ALDEHYDES
ALKALINE EARTH METALS
BATCH CULTURE
BIOCONVERSION
BIOLOGICAL EFFECTS
BIOSYNTHESIS
CARBOHYDRATES
DATA
ELEMENTS
ETHANOL
EXPERIMENTAL DATA
FERMENTATION
GLUCOSE
HEXOSES
HYDROXY COMPOUNDS
INFORMATION
MAGNESIUM
METALS
MONOSACCHARIDES
NUMERICAL DATA
NUTRITIONAL DEFICIENCY
ORGANIC COMPOUNDS
SACCHARIDES
SYNTHESIS