Bacillus subtilis (Bacillus subtilis, hay bacillus): biochemical properties, cultivation and application

Science 2023

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Bacillus subtilis (Bacillus subtilis, hay bacillus): biochemical properties, cultivation and application
Bacillus subtilis (Bacillus subtilis, hay bacillus): biochemical properties, cultivation and application
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Not everyone can answer what Bacillus subtilis is. However, most of us are very familiar with this creature. Anyone who has ever lifted freshly cut grass has seen a whitish coating under it. This is the bacteria Bacillus subtilis. This bacterium, unusually common in nature, was originally grown on broken hay. That's why we call it hay stick.

Microbiological "model"

Different branches of biology have their own "model" organisms, which become the main object of study and experiments. For example, in genetics, the Drosophila fruit fly has become such an organism, in microbiology of protozoa - the ciliate shoe, and in bacteriology - Bacillus subtilis.

Thanks to this bacterium, the process of spore formation and the mechanism of operation of the motor motor of flagellar bacteria have been thoroughly studied. Molecular biologists were among the first to decipher the genome of this bacillus.

Today, Bacillus subtilis is grown in weightlessness and its effect on the genome of the population is being studied. In space biologyirradiated with cosmic ultraviolet and explore its ability to survive in conditions close to those on Mars.

rod-shaped bacterium

Short description

The hay stick was first described in 1835 by the German biologist Christian Gottfried Ehrenberg (1795-1876). The bacillus grew well on hay extract, which is why it received the first part of the name. Outwardly, these are rod-shaped bacteria, so they are called rods.

These are rather large bacilli (length up to 0.008 mm, diameter 0.0006 mm), which can be seen even in a school microscope. Bacillus subtilis has many flagella on the surface of the cell membrane.

These mobile bacteria are aerobes (they need atmospheric oxygen to ensure their vital processes). But some strains (artificially grown genetically homogeneous groups) can become facultative anaerobes.

The optimum temperature for hay sticks is between 25 and 30 degrees Celsius. But they will survive at -5 and at +150 degrees, thanks to the formation of spores.

Bacillus subtilis

Nutrition and distribution

In nature, Bacillus subtilis lives in the soil, but is found in water and dust. These microorganisms are part of the microflora of our intestines and the gastrointestinal tract of animals.

These are saprophytic bacteria, they feed on organic residues. The main source of energy for them is polysaccharides based on glucose of vegetable (cellulose and starch) and animal (glycogen) origin.

The metabolic products of hay bacillus are amino acids, vitamins, various enzymes, antibiotics. Man has long learned to use these features of bacteria in his activities.

Bacillus subtilis in the soil

Features of biochemistry

The most important properties of hay sticks include their ability to increase the acidity of the environment and produce antibiotics.

These bacilli are antagonists for yeast fungi, salmonella, amoeba Proteus and dysentery, strepto- and staphylococci.

In the process of life, hay bacilli synthesize amino acids, antibiotics, enzymes and immunoactive substances. Today, strains of this bacillus are used in the production of enzymes, antibiotics, biological products (odor enhancers, food additives), insecticides.

Bacillus subtilis in a petri dish

How to grow a colony

In Petri dishes, colonies of these bacilli look like wrinkled pancakes with wavy edges of white or pinkish color, dry and velvety structure.

In laboratories, hay bacillus strains are grown on meat-peptone broth or agar, artificial media, or on a substance with the remains of a plant organism.

At home, it is enough to boil ordinary hay and put the infusion in a warm place for 1-2 days. On the surface of the water infusion, a film will appear exclusively from the bacteria of the hay bacillus. All other microorganisms will die when boiled.

The structure of the hay stick

Opportunistic pathogens

Enteringthe composition of the microbiota of the gastric tract, hay bacillus promotes the decomposition of complex polysaccharides (cellulose), breaks down proteins, and contributes to the inhibition of pathogenic microflora.

In open wounds on the human body, these bacteria secrete antibiotics and enzymes that destroy dead tissue. It has already been proven that these bacilli have a negative effect on pathogenic organisms during surgical infection (Salmonella, Staphylococcus, Streptococcus).

However, they are conditionally pathogenic, because they have such negative abilities for people:

  • May cause an allergic rash.
  • Cause food poisoning when eating spoiled food.
  • May cause eye infections.

Hay stick and man

From the point of view of human use, bacteria are of interest in the context of two questions:

  • How can they help us.
  • How can they harm us.

Human cooperation with hay stick began a long time ago. Today, microbiologists have grown many strains of this bacillus with well-defined qualities. This microorganism is used in crop production, animal husbandry, the production of medicines, waste management methods within the framework of the green economy.

Bacillus subtilis preparations

Bacilli in medicine

Biochemical characteristics make it possible to widely use this organism in the production of medicines. Bacillus subtilis, according to pharmacological characteristics, refers to:

  • Antidiarrheals.
  • Immunomodulators.

Preparations based on hay bacillus ("Sporobacterin", "Bactisubtil", "Biosporin") are prescribed for dysbacteriosis of the intestines and genital tract, in the postoperative period with purulent complications.

However, it is worth remembering about contraindications, the main of which is hypersensitivity or intolerance to the components of the drug.

This microorganism is also widely used in dietary supplements.

Other applications

In crop production, the most common preparation based on hay bacillus is "Fitosporin". It is effective in the fight against fungal and bacterial diseases of cultivated plants. At the same time, the fruits can be eaten even on the day they are sprayed with the drug.

In animal husbandry, the peculiarity of hay sticks is used to ferment cellulose, which contributes to better absorption of carbohydrates by animals. In addition, antibacterial drugs based on this stick are widely used in animal husbandry, poultry farming, and fish farming.

Proteases and amylases, the enzymes of hay bacillus, are commercially produced and are used in detergents, tanning and cleaning preparations.

Bacillus subtilis Bacillus subtilis

There are individual strains that have a very narrow specialization. For example, they are used to make Japanese soybean-based natto.

Future plans

The development of genetic engineering is also impossible withoutbacteria. And the hay stick is not the last in the list of "models" for creating transgenic organisms.

We have already written about assistance in space exploration.

Today, the study of the distribution of hay bacillus in nature is actively developing in terms of environmental safety. There are already works to assess the state of the environment based on the correlation of the distribution of this unique microorganism in the ecotope.

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