SUBSTRET AND MEDIA
COMPOSITION AND IDEAL
alcoholic fermentation, also
referred to as, Ethanol
fermentation, is a biological
process in which sugars such as
glucose, fructose, and sucrose are
converted into cellular energy and
thereby produce ethanol and carbon
dioxide as metabolic waste
products. Because yeasts perform
this conversion in the absence of
oxygen ethanol fermentation is
classified as anaerobic.
C2H5OH + CO2
100 Kg 51.1 Kg 48.9 Kg
Theoretical Yield : 51.1%
Sugar ====> Alcohol + Carbon dioxide gas + Energy
(Glucose) (Ethyl alcohol)
Nutrient Raw material
Carbon molasses, starch
Nitrogen corn steep liquor, soybean
meal, pure ammonia or
ammonium salts, urea, nitrate
salts, phosphate salts
biotin, yeast extract, beef
extract, corn steep liquor,
wheat germ meal
CONDITIONS FOR FERMENTATION
Carbon sources: pure sugar or crude
Growth factors: can be provided in the
form of molasses.
Temperature: 21-26 F. Temp. can be
controlled by heating or cooling of
Time: Depends on yeast strain.
Usual time is between 30 to
Yield: 0.4 gallon of ethyl alcohol per
gallon of molasses. 90%
carbohydrates can be
converted in to alcohol.
FERMENTATION PROCESS CARRY
continuous fermentation is used
because of several advantages.
In range of 3% to 10% with an
average about 4%
10 -18%. Concentrations
greater than 20% are not employed as
they could be detrimental to yeast.
Distillation is a separation process for a
mixture of liquids or oils. It relies on
differences in the boiling points of the
component liquids to be separated.
Alcohol can be obtained by distillation
and column is known as rectified
Can also be recovered by fractional
distillation. Distillate contains 95.6%
ethyl alcohol and 4.4% water.
Three byproducts generated
1.Carbon dioxide- used for production of
dry ice and pure form used for
preparation of soft drinks.
2.Yeast biomass- used for animal fodder
because it contains high protein,
3.Distillery effluents- used as a fertilizer
and animal feed.
Growth Tolerance Production Tolerance
Ethanol production ceases
15% wt/vol or higher
Some alcohols, mainly ethanol
and methanol can be used as an alcohol
Alcohols have applications in industry
and science as reagents or solvents
ethanol can be used as a solvent in
medical drugs, perfumes and vegetable
essences such as vanilla
Ethanol can be used as
an antiseptic to disinfect the skin.
Thus alcohol production is an
important fermentation because of
1.Gives ethyl alcohol used for
consumption as well as industrial
2.Gives byproducts like carbon dioxide,
yeast biomass, fertilizer etc.
3.Gives effective utilization of agro-
waste eg. Molasses, sulphite waste