Difference Between Ethanol Fermentation and Lactic Acid Fermentation

Thekey difference在乙醇发酵和乳酸发酵之间ethanol fermentation producesethanolas a byproduct, whereas lactic acid fermentation produceslactateas a byproduct.

Fermentation is a process that takes place under anaerobic conditions. Therefore, it occurs in the absence of molecular oxygen. Many microbes, plants, and human muscle cells are capable of undergoing fermentation. During fermentation, sugar molecules are converted intoalcohols和酸。这种化学反应在乳制品，面包产品和酒精饮料的工业生产中具有很大的用途。

内容

1.Overview and Key Difference
2.What is Ethanol Fermentation
3.乳酸发酵是什么
4.Side by Side Comparison – Ethanol Fermentation vs Lactic Acid Fermentation in Tabular Form
5.概括

What is Ethanol Fermentation?

乙醇发酵，也称为酒精发酵, is a biological process in which a conversion of sugars into cellular energy occurs. The sugar molecules that can undergo this process include glucose, fructose, and sucrose. During the production of cellular energy, this process produces ethanol and carbon dioxide as well. These are the byproducts of ethanol fermentation.

这种发酵发生在酵母菌存在和没有氧气的情况下。因此，我们可以将其命名为厌氧生物学过程。此外，此过程发生在一些鱼类（例如金鱼）中，并在没有足够的氧气时为这些鱼提供能量。

Usually, ethanol fermentation converts one mole of glucose into two moles of ethanol and two moles of carbon dioxide. This produces two moles of ATP. When considering the sucrose molecule, it contains two sugar molecules: glucose and fructose linked to each other. Therefore, when sucrose is used for ethanol fermentation, the initial step is the cleavage of these molecules with the use of the invertase enzyme to break down the glycosidic bond between glucose and fructose. Thereafter, glucose is broken down into two pyruvate molecules through glycolysis, and then pyruvate is converted into ethanol and carbon dioxide through two steps.

乳酸发酵是什么?

乳酸闭ntation is a biological process in which glucose or a similar sugar molecule is converted into cellular energy and metabolite lactate. Here, the sugar molecule can be either glucose or another six-carbon sugar molecule. Disaccharides such as sucrose can also be used. Lactate is lactic acid in solution. Lactic acid fermentation is an anaerobic process that takes place in some bacteria and animal cells, including muscle cells.

In the presence of oxygen in cells, the cell tends to bypass the fermentation process and perform cellular respiration. But there are some facultative anaerobic organisms that can perform both fermentation and respiration in the presence of oxygen gas.

There are three ways lactic acid fermentation can occur: homofermentative process, heterofermentative process, and bifidum pathway. In the homofermentative process, homofermentative bacteria can convert glucose into two molecules of lactate, and they can use this reaction to perform substrate-level phosphorylation in order to make two ATP molecules.

What is the Difference Between Ethanol Fermentation and Lactic Acid Fermentation?

乙醇发酵或酒精发酵是一种生物学过程，其中糖转化为细胞能量。同时，乳酸发酵是一种生物学过程，其中葡萄糖或类似的糖分子转化为细胞能和代谢物乳酸。乙醇发酵和乳酸发酵之间的关键区别在于，乙醇发酵产生乙醇作为副产品，而乳酸发酵产生乳酸作为副产品。此外，乙醇发酵的效率为29％，而乳酸发酵的效率为41％。

The below infographic lists the differences between ethanol fermentation and lactic acid fermentation in tabular form.

概括– Ethanol Fermentation vs Lactic Acid Fermentation

Ethanol fermentation is a biological process in which a conversion of sugars into cellular energy occurs. Lactic acid fermentation is a biological process in which glucose or a similar sugar molecule is converted into cellular energy and the metabolite lactate. The key difference between ethanol fermentation and lactic acid fermentation is that ethanol fermentation produces ethanol as a byproduct, whereas lactic acid fermentation produces lactate as a byproduct.

Reference:

1. “Lactic Acid Fermentation.”维基百科，维基梅迪亚基金会，2021年3月2日，Available here.

Image Courtesy:

1. “Ethanol fermentation-1” By Davidcarmack – Own work(CC BY-SA 3.0)viaCommons Wikimedia
2. Neurotiker的“乳酸 - 骨骼 - 骨骼” - 通过自己的作品（公共领域）通过Commons Wikimedia