Fermentation and application range of lactic acid bacteria(lactobacillus)

Lactic acid bacteria (LAB) are bacteria that can ferment sugars into lactic acid in an anaerobic or slightly anaerobic environment. They are widely found in nature, including the human and animal gut, fermented foods, plants and other environments. The fermentation of lactic acid bacteria not only provides energy for its growth, but also produces lactic acid, acetic acid, carbon dioxide and other metabolites, giving it unique physiological functions and flavor. This paper will discuss the fermentation process of lactic acid bacteria and its wide application in various fields.

Fermentation process of lactic acid bacteria

The fermentation process of lactic acid bacteria is mainly through the fermentation of sugars to obtain energy, the most common sugar source is glucose, lactose, sucrose and so on. Lactic acid bacteria convert these sugars into lactic acid during fermentation. Lactic fermentation can be divided into two types: lactic fermentation and alkyd fermentation.

Homolactic fermentation: In this process, the lactic acid bacteria completely convert the sugars into lactic acid, and no other by-products are produced. This is the main metabolic mode of most lactic acid bacteria.

Heterolactic fermentation: In heterolactic fermentation, lactic acid bacteria simultaneously produce metabolites such as lactic acid, acetic acid, carbon dioxide, and a small amount of ethanol. Some lactic acid bacteria, such as Lactococcus lactis and Lactobacillus casei, have the characteristics of heterolactic fermentation.

Lactic acid bacteria convert sugars into lactic acid through a specific enzyme system during fermentation. Lactose (the main sugar in dairy products) is hydrolyzed to glucose and galactose by the action of lactase, and these two simple sugars are further fermented into lactic acid by lactic acid bacteria.

Lactic acid, the metabolite of lactic acid bacteria, usually acidifies the environment after fermentation, thereby reducing the pH value and providing a favorable environment for the further growth of lactic acid bacteria. In addition, the accumulation of lactic acid can also inhibit the growth of some harmful microorganisms, which has a natural preservative effect.

Application range of lactic acid bacteria

Because of its unique fermentation ability and diverse biological functions, lactic acid bacteria have been widely used in many fields, especially in the food industry, health products industry and biomedicine.

1. Food fermentation

Lactic acid bacteria is the key microorganism of traditional fermented food, which is widely used in the fermentation of dairy products, meat, vegetables, juice and so on.

Dairy products: such as yogurt, cheese, butter, etc., lactic acid bacteria can make milk and other dairy products fermentation and produce lactic acid, and then make the product sour taste, increase nutrients (such as vitamin B group, calcium, etc.), improve taste and shelf life. For example, common lactic acid bacteria in yogurt and cheese include Lactobacillus bifidus, Lactobacillus acidophilus, and so on.

Meat products: Lactic acid bacteria are also widely used in the fermentation of meat products, such as sausages, ham and so on. By fermentation of lactic acid bacteria, meat products can not only obtain special flavor, but also extend its shelf life.

Plant fermented foods: such as sauerkraut, pickles, soy sauce, vinegar, etc., lactic acid bacteria play a key role in fermentation in these foods, helping to produce sour taste and flavor.

2. Health food and probiotic products

Lactic acid bacteria are considered as probiotics, which can improve intestinal health, enhance immunity and regulate intestinal flora. By colonizing the intestinal tract, lactic acid bacteria can inhibit the growth of pathogenic bacteria and improve the function of digestive system. Therefore, lactic acid bacteria are widely used in health food and probiotic products.

For example, probiotic products (such as probiotic yogurt, probiotic capsules, etc.) usually contain a lot of active lactic acid bacteria, which can help promote intestinal motility, relieve constipation, reduce diarrhea and other gastrointestinal problems.

MIKEBIO 50-500-6000L fermentation system for Lactic acid bacteria project 

3. Biomedicine

The application of lactic acid bacteria is not limited to the field of food and health care, in recent years, lactic acid bacteria has also shown great potential in the field of biomedicine. Lactic acid bacteria have anti-tumor, anti-oxidation, antibacterial and other biological activities, and have made initial progress in some drugs and treatments. For example, some lactic acid bacteria can play a role in the treatment of cancer, allergies and other diseases by regulating the immune system.

In addition, lactic acid bacteria can also synthesize some important bioactive substances, such as vitamins, amino acids and organic acids, which play a positive role in human health. The fermentation process of lactic acid bacteria can also generate some natural compounds with biological activity, which have a wide range of potential applications in drug development and clinical therapy. 3. Biomedicine

The application of lactic acid bacteria is not limited to the field of food and health care, in recent years, lactic acid bacteria has also shown great potential in the field of biomedicine. Lactic acid bacteria have anti-tumor, anti-oxidation, antibacterial and other biological activities, and have made initial progress in some drugs and treatments. For example, some lactic acid bacteria can play a role in the treatment of cancer, allergies and other diseases by regulating the immune system.

In addition, lactic acid bacteria can also synthesize some important bioactive substances, such as vitamins, amino acids and organic acids, which play a positive role in human health. The fermentation process of lactic acid bacteria can also generate some natural compounds with biological activity, which have a wide range of potential applications in drug development and clinical therapy.

4. Agriculture and the environment

In agriculture, lactic acid bacteria, as a kind of beneficial microorganism, can effectively inhibit the growth of plant pathogens through biological control and reduce the use of chemical pesticides. In addition, lactic acid and acetic acid, the metabolites of lactic acid bacteria, can be used as natural biopesticides to protect crops from pests and diseases.

In the field of environmental protection, lactic acid bacteria also has its unique application. For example, lactic acid bacteria can be used in sewage treatment to degrade harmful substances through organic acids produced during fermentation.

The future prospects of lactic acid bacteria fermentation

The future prospect of lactic acid bacteria fermentation is very broad, with the continuous progress of science and technology and the improvement of consumer demand for health, lactic acid bacteria fermentation in the food industry, health care, environmental protection and other fields have shown great potential.

As an important microorganism, lactic acid bacteria, with its unique fermentation function, has shown great application potential in food, health care products, biomedicine, agriculture and other fields. With the continuous progress of science and technology, the research on lactic acid bacteria continues to deepen, and new lactic acid bacteria strains, fermentation processes and application fields will continue to emerge, promoting the development of lactic acid bacteria industry towards a more diversified, personalized and accurate direction. It can be predicted that lactic acid bacteria will play an increasingly important role in the future, especially in improving human health, ensuring food safety and environmental protection.