Liberation of Carbon Dioxide gas during Fermentation


To study the liberation of Carbon dioxide gas during fermentation.



All living organisms use respiration to obtain the energy needed to run their cellular processes. Most of the organisms respire in the presence of Oxygen. This type of respiration is called aerobic respiration whereas some organisms respire in the absence of Oxygen such type of respiration is called Anaerobic respiration.   

The liberation of Carbon dioxide during fermentation is governed by several fundamental biochemical and physiological principles. 

  • Biochemical Pathway: During fermentation, the biochemical pathway involves the breakdown of sugars, such as glucose, into simpler compounds, typically pyruvate. This process occurs through glycolysis, which leads to the generation of energy in the form of Adenosine triphosphate (ATP). The pyruvate generated from glycolysis is further converted into Ethanol or Lactic acid, depending on the specific type of fermentation. In this process, Carbon dioxide is released as a byproduct. 
  • Yeast and Bacterial Activity: The liberation of Carbon dioxide during fermentation is primarily attributed to the activity of microorganisms such as yeast and certain bacteria. Yeast, for example, undergoes fermentation, converting sugars into Ethanol and Carbon dioxide in the absence of Oxygen. This microbial activity plays a pivotal role in various industries, including the production of beer, wine, and biofuels. 
  • Fermentation Conditions: The liberation of Carbon dioxide is influenced by several key fermentation conditions, including temperature, pH levels, nutrient availability, and the presence of specific enzymes. These factors directly impact the metabolic activity of microorganisms involved in the fermentation process and subsequently affect the rate of Carbon dioxide release. 
  • Regulatory Enzymes: Various regulatory enzymes control the biochemical pathways involved in fermentation. Enzymes such as pyruvate decarboxylase and alcohol dehydrogenase facilitate the conversion of pyruvate into Ethanol, leading to the liberation of Carbon dioxide as a byproduct. The regulation of these enzymes is crucial for controlling the overall efficiency and yield of the fermentation process. 


By converting starch or sugar to alcohol or an acid anaerobically is called fermentation. The fermentation process, is a metabolic process that is enzyme-catalysed and releases energy. This process is widely utilized in the production of alcoholic beverages, bread, and various industrial chemicals. Zymology is the field of study of fermentation. 

Types of Fermentation

  1. Homo fermentation – Only one product is formed.
  2. Hetero fermentation – More than one product is formed.

Lactic acid Fermentation  

A metabolic process called Lactic acid fermentation turns six-carbon sugars like glucose or other six-carbon sugar disaccharides like sucrose or lactose into the metabolite lactate and cellular energy, which is Lactic acid in solution. 

Alcoholic Fermentation 

Alcoholic fermentation is a sophisticated biochemical procedure in which yeast converts sugar into Ethanol, Carbon dioxide, and other metabolic by-products. 

Acetic acid Fermentation

The fermentation of Acetic acid is a highly exothermic process that raises the temperature to around 50°C. Only 2% to 4% of lactate is transformed into Acetate. A portion of lactate is converted into acetoin while another portion undergoes TCA cycle oxidation. 

Butyric acid Fermentation

Butyric acid fermentation able to oxidise sugar and occasionally amylose and pectin to pyruvate. It is done by anaerobic bacteria which mainly belong to the genus Clostridium. 

Advantages of Fermentation 

Fermentation is the oldest metabolic process and it used in both eukaryotes and prokaryotes. It is used in many industries, and the products formed are:

  • Wine 
  • Biofuels 
  • Yoghurt 
  • Pickles 
  • Sour foods containing lactic acid 
  • Beer 
  • Bread
  • Certain antibiotics and vitamins 

Learning Outcomes

  • Students understands about fermentation.
  • Students understand the fields in which the fermentation works.  
  • Students can know about the products which are fermented in their day-to-day life.