Fermentation by Yeast

Fermentation by Yeast

Definition

• Fermentation: a metabolic process that converts sugar into energy in the absence of oxygen
• Yeast fermentation: a type of fermentation that occurs in yeast cells, resulting in the production of ethanol and carbon dioxide

Process of Fermentation

1. Glycolysis: Yeast breaks down glucose into pyruvate, producing ATP and NADH
2. Pyruvate conversion: Pyruvate is converted into acetaldehyde, releasing CO2
3. Alcohol production: Acetaldehyde is reduced to ethanol, regenerating NAD+

Types of Fermentation

• Alcoholic fermentation: Yeast converts glucose into ethanol and CO2
• Lactic acid fermentation: Yeast converts glucose into lactic acid (occurs in muscle cells and some bacteria)

Importance of Fermentation by Yeast

• Food and beverage production: Fermentation is used to produce bread, beer, wine, and biofuels
• Industrial applications: Fermentation is used to produce bioactive compounds, such as antibiotics and vitamins
• Biotechnology: Fermentation is used to produce recombinant proteins and other bioproducts

Factors Affecting Fermentation

• Temperature: Optimal temperature range for yeast fermentation is between 25°C to 37°C
• pH: Yeast prefers a slightly acidic to neutral pH (5.5-7.5)
• Nutrient availability: Yeast requires a source of sugar, nitrogen, and other nutrients for fermentation
• Oxygen presence: Yeast fermentation occurs in the absence of oxygen, but some oxygen is required for yeast growth and reproduction

Fermentation by Yeast

Definition

• Fermentation is a metabolic process that converts sugar into energy in the absence of oxygen
• Yeast fermentation produces ethanol and carbon dioxide as byproducts

Process of Fermentation

• Glycolysis: glucose is broken down into pyruvate, producing ATP and NADH
• Pyruvate is converted into acetaldehyde, releasing CO2
• Acetaldehyde is reduced to ethanol, regenerating NAD+

Types of Fermentation

• Alcoholic fermentation: glucose is converted into ethanol and CO2
• Lactic acid fermentation: glucose is converted into lactic acid (occurs in muscle cells and some bacteria)

Importance of Fermentation by Yeast

• Used in food and beverage production (bread, beer, wine, and biofuels)
• Used in industrial applications (production of bioactive compounds, antibiotics, and vitamins)
• Used in biotechnology (production of recombinant proteins and other bioproducts)

Factors Affecting Fermentation

• Temperature: optimal range is between 25°C to 37°C
• pH: yeast prefers a slightly acidic to neutral pH (5.5-7.5)
• Nutrient availability: yeast requires a source of sugar, nitrogen, and other nutrients
• Oxygen presence: yeast fermentation occurs in the absence of oxygen, but some oxygen is required for yeast growth and reproduction