The document summarizes the history and process of ethanol production from cane molasses through Saccharomyces cerevisiae yeast. It discusses how Brazil first introduced renewable fuels and developed ethanol production from sugarcane in the 16th century. It then covers the development of the Brazilian national alcohol program in 1975 during an oil crisis to produce ethanol at large scales. The industrial production process involves using ethanol tolerant S. cerevisiae yeast and fermenting sugarcane molasses. Aeration is important to maximize yeast growth and increase carbohydrate utilization through respiration rather than fermentation alone. Downstream processing is also briefly mentioned.

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ETHANOL
PRODUCTION
BY CANE MOLASSES
THROUGH Saccharomyces
cerevisiae
PRESENTED BY-
SHALINI SAINI
M.Sc 2nd
SEM
ROLL NO.1810

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HISTOR
Y
Brazil is the country that first introduce the renewable fuel in
its energy matrix. A large industry from arose its pioneering
initiative and nowadays detains most economically feasible
process for bioethanol production.
The Brazilian knowledge in ethanol production from sugarcane
began to be developed in colonial period beginnning of the 16th
century, when farmers used to produced the Brazilian sugarcane
distilled spirit, the“cachaca” ,(By Basso and Rosa, 2010).
Then ,since in beginnning of 20th
century Brazil has been using
Ethanol for energetics purposes.
In 1905, the first test of using ethanol as a fuel for vehicles
engines wre performed. These test, test provoked official
attention and resulted in law publishedin 1931, which determined

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that ethanol should be mixed to the gasoline at a rate of
5%.
Then this new technology needed economical and political
investment to keep its viability and in early 1970 when the oil
crisis trippled oil import cost to Brazil in 1973,the sugar prices is
also climbing upward since the mid- 60’s, declined sharply in 1974
(Sandalow,2006).During this drastic changes in global fuel market,
The country launched the Brazilian national alcohol program
(PROALCOOL) in 1975, aiming at large ethanol generation by local
Distilleries and engines adaptation to consume E20 mix(20% and
80%, ethanol and gasoline, respectively) or even pure anhydrous
Ethanol (Amorim and Leao,2005).
In the 1980s, the major cars companies accorded to install ass-
-embly lines for 100% ethanol cars.
At the first of 2000, flex fuel engines were exclusivly desingned
locally to Brazilizn market.

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STRUCTURAL
FORMULA

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THE INDUSTRIAL PROCESS
The production of ethanol on industrial scale included following
content;
Feedstock
Substrate fermentation
Fermentation
IMPACT Of INDUSTRIAL CONDITIONS ON YEAST
PHYSIOLOGY AND POPULATION DYNAMICS
Industrial stress
•Osmotic stress
•Ethanol stress
•Acid stress
•Other stesses
•Bacterial contamination

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The importance of yeast glycogen and trehalose during stress
Conditions
The starter strain and competition with indigenous Saccharomyces
during fermentation
Selection of suitable strains from the biodiversity found in distilleries
Application
Inoculum preparation
Ethanol tolerant, non-amylolytic and flocculating yeast, Saccharomyces
cerevisiae yest is used. The culture was preserved at 4°C by regular subculturing
(one in three months) over MYPD agar.
For inoculum preparation, flask containing finger millet hydrolysate (10%
reducing sugar) supplemented with 1% urea and 2% yeast extract were used and
autoclaved (121°C for 15-20min.).After cooling at room temp.a loopful of cells
from a colony on YPD plates was transferred to each flask. Yeast cells was pre-
Cultured at 30°C on a rotatory shaker for 24h.The cells were harvested by centr-
-fugation at2000╳g for 5 min. the pellets was washed twice with 30mM/L EDTA
to ensure floc disruption and finally washed and suspended in sterile deionized
water.

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Immobilzation of yeasts cell for ethanol production

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Aeration
 Highly aerobic culture conditions are used in the production of
Specifically baker”s yeast (S. cerevisiae)to maximize the cell growth.
 The modern technique of baker yeast production is based on applying the
principle of the pastuer reaction at the limit value of its aeration. Pastuer
defined fermentaton without air.Its biochemistry involves the breakdown
of carbohydrates only to stage of ethanol.
 Under aeobic conditions, however maximum growth occurs and the
efficiency
Of utilization of carbohydrates increases as respiration and the breakdown of
the carbohydrate to carbon dioxide and water becomes complete.
Generally oxygen has the following basics functions-
1. Inhibits fermentation
2. Increases respiration
3. Agitation of the medium
4. Removal of toxic end products
5. Stimulation of vegetative growth

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Oxygen is used in the synthesis of unsaturated fatty acids and
sterols which is form the cell membrane. These molecules are
important for both growth and fermentation and serve as a mean for
storing oxygen within the cell. They also necessary for increasing cell
mass involving.
The overall uptake of nutrients and determing alcohol tolerance.
oxygen stimulates the synthesis of molecules necessary for yeast to
metabolize and take up maltose and other sugars.

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DOWNSTREAM PROCESSING

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