The germ theory of fermentation or fermentation theory is now obsolete that is replaced by the germ theory of disease. Luis Pasteur discovered that microorganisms cause fermentation and theses microbes originate from preexisting living cells that are called biogenesis.
The germ theory of fermentation:
The discovery of the germ theory of fermentation offered proof of biogenesis and disproved spontaneous generation. The concept that stats that microorganisms arise from nonliving matters is called Spontaneous generation.
Before Pasteur, many Scientists believed that air can convert sugar into alcohol. But Pasteur first showed that microorganisms for example yeasts can convert sugar into alcohol in the absence of air. This type of conversion is known as fermentation.
Many beers and wines are made using this process. But in aerobic conditions bacteria can spoil wine and beer by converting alcohol into vinegar.
At the time of Pasteur, people didn’t know the cause of disease. But Pasteur’s discovery of the fermentation process proceeds many scientists to find out the causes of disease. That is; the role of microorganisms in the fermentation process in making a physical and chemical change in the fruits or beverages may have a link in causing disease.
The germ theory of fermentation leads to develop the germ theory of disease. The germ theory of disease states that disease caused by microorganisms.
But before the introduction of the germ theory of disease, it is known as the germ theory of fermentation.
Read another article about the first scientist to find that microorganisms cause disease.
Fermentation is the process that converts sugars in an alcoholic beverage or acidic dairy products. This process may occur in the presence or absence of air.
There are two types of fermentation process such as Lactic acid fermentation and alcohol fermentation.
Lactic acid fermentation:
In this process, one molecule of glucose is converted to two molecules of pyruvic acids and two molecules of pyruvic acids are converted to two molecules of lactic acids.
Two important lactic acid bacteria such as streptococcus and Lactobacillus carry this process.
Yogurt and Sauerkraut are produced through this process from milk and fresh cabbage respectively.
In this process, one molecule of glucose is converted to two molecules of pyruvic acids and two molecules of pyruvic acids are converted to two molecules of acetaldehyde and then to two molecules of Ethanol.
Both bacteria and yeast carry this process.
Beer and wine are produced through this process.