Fermentation and the production of ethanol By Olivia Bates

Introduction Ethanol Fermentation What Fermentation is used for About Fermentation Comparisons of making Ethanol Fermentation to make wine.

Ethanol Fermentation is a form on anaerobic respiration which is primarily used by yeast when oxygen is not present . Ethanol Fermentation is also referred to as Alcohol Fermentation. Fermentation Ethanol is produced during the process of fermentation. Yeast is added to a sugar solution and left in the absence air for several days. This is an anaerobic exercise.

Fermentation is used for making food, wine, beer, tea and bread. Demijohn of wine. Make wine at home. Fermentation is used for making food, wine, beer, tea and bread. It is used to make products such as yoghurt, cheese and soy sauce. fermentation can refer to the use of yeast to change sugar into alcohol or the use of bacteria to create lactic acid in certain foods.

Fermentation has been used for thousands of years, but it is a slow process and only produces a 15% ethanol solution. However there are other methods of producing ethanol. A new alternative of making ethanol involves the use of genetically modified E.coli bacteria. These bacteria have had a gene introduced to them that is capable of converting all types of carbohydrates found in plant cells to ethanol. Genetically modified E.coli can produce ethanol from waste biomass such as sugar cane residues, corn husks, wood and other waste organic material.

Three comparisons of making ethanol Fermentation Hydration of ethane Using E.coli Bacteria Resources used Renewable resources e.g. sugar cane and maize Finite resources - ethane Renewable resources – waste biomass such as corn husks and wood Type of process Batch process where everything is mixed together and left for several days; the ethanol is then removed and distilled. Continuous process where the reactants are passed over the catalyst Batch process where the biomass and bacteria are mixed and left for several days; the ethanol formed must be distilled. Reaction conditions 37◦C and atmosphere pressure High temperature and pressured 30-37 ◦C and atmosphere pressure Rate of reaction slow fast Purity of product 15% pure 96% pure 5% pure

Fermentation of wine The process of fermentation in wine is the catalyst function that turns grape juice into an alcoholic beverage. During the fermentation process yeast interacts with sugars in the juice to create ethanol. When making wine the temperature and speed of fermentation is an important consideration as well as the amount of oxygen present at the start of the fermentation.

Bibliography http://en.wikipedia.org/wiki/Fermentation_(wine) 21st century science (pages 104-107)