Not everyone can answer what Bacillus subtilis is. However, most of us are very familiar with this creature. Anyone who ever lifted freshly cut grass, he saw a whitish coating under it. These are the bacteria Bacillus subtilis (Bacillus subtilis). Unusually widespread in nature, this bacterium was originally grown in fine hay. That is 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 experimentation. For example, in genetics, the fruit fly of Drosophila became such an organism, in microbiology of protozoa, the ciliates, and in bacteriology, the Bacillus subtilis.
Thanks to this bacterium, the process of spore formation and the mechanism 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 zero gravity and its effect on the genome of the population is being studied. In space biology, it is irradiated with cosmic ultraviolet and its ability to survive under conditions close to those on Mars is investigated.
Short characteristic
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 quite large bacilli (length up to 0.008 mm, diameter 0.0006 mm), which can be seen even with a school microscope. On the surface of the cell membrane in Bacillus subtilis there are many flagella.
These motile bacteria are aerobes (they need atmospheric oxygen to provide vital processes). But some strains (artificially grown genetically homogeneous groups) can become facultative anaerobes.
The optimal temperature regime for a hay stick is in the range from 25 to 30 degrees Celsius. But they will survive at -5 and at +150 degrees, due to the formation of spores.
Nutrition and distribution
Bacillus subtilis lives in nature in soil, but is found in water and in dust. These microorganisms go into the microflora of our intestines and the gastrointestinal tract of animals.
These are saprophyte bacteria, they feed on organic residues. The main source of energy for them is polysaccharides based on glucose of plant (cellulose and starch) and animal (glycogen) origin.
The products of the metabolism of hay bacillus are amino acids, vitamins, various enzymes, antibiotics. A person has long learned to use these features of bacteria in his activity.
Features of biochemistry
The most important properties of hay bacillus include their ability to increase the acidity of the medium and produce antibiotics.
These bacilli are antagonists for yeast, salmonella, amoeba protea 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.
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 velvet structure.
In laboratories, hay bacillus strains are grown on meat and peptone broth or agar, artificial media, or on substances 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 will appear a film exclusively from bacteria of hay bacillus. All other microorganisms will die when boiled.
Conditionally pathogenic organisms
Being part of the microbiota of the gastric tract, hay bacillus promotes the decomposition of complex polysaccharides (cellulose), breaks down proteins, and inhibits 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 negatively affect pathogenic organisms during surgical infection (salmonella, staphylococcus, streptococcus).
However, they are conditionally pathogenic, because they have such negative abilities for people:
- May cause allergies in the form of a rash.
- Lead to food poisoning when spoiled foods are consumed.
- May cause infections of the mucous membranes of the eyes.
Hay stick and man
In terms of human use, bacteria are interesting in the context of two questions:
- How can they help us.
- How can they harm us.
With a hay stick, human cooperation 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 drugs, waste management methods in the framework of the "green" economy.
Bacillus in medicine
Biochemical features make it possible to widely use this organism in the production of medicines. Pharmacological signs of bacillus subtilis include:
- Antidiarrheal drugs.
- Immunomodulators.
Preparations based on hay bacillus (Sporobacterin, Bactisubtil, Biosporin) are prescribed for intestinal and genital tract dysbiosis, 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 widely used in dietary supplements.
Other applications
In plant growing, the most common drug based on hay bacillus is Fitosporin. It is effective in combating fungal and bacterial diseases of cultivated plants. In this case, the fruits can be eaten even on the day of spraying them with the drug.
In animal husbandry, a feature of hay bacillus 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, fish farming.
On an industrial scale, proteases and amylases are produced - hay bacillus enzymes, which are part of detergents, preparations for the preparation and cleaning of hides.
There are individual strains that have a very narrow specialization. So, they are used to prepare soya-based Japanese natto dishes.
Future plans
The development of genetic engineering is also impossible without bacteria. And hay bacillus 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 spread of hay bacillus in nature from the point of view of environmental safety is actively developing. There is already work to assess the state of the environment based on the correlation of the distribution of this unique microorganism in the ecotope.