Nature everything is so harmoniously arranged that in this world everyone has his own place and is engaged in the functions that are assigned to him, whether it is the crown of nature - an incredibly complex human or the most microscopic organism. Everyone plays their part to make our world a better place. This also applies to various bacteria, which, according to the great plan of the creator of the world, bring people not only benefits, but also certain harm. Consider what thermophilic lactic acid bacteria are and what is their place in our lives. Are they good or bad?
Features and essence
A whole army of various microorganisms lives on our planet, invisible to the eye, but very active and not always useful. One such beneficial microformation is the thermophilic bacterium. The bacterium lives in hot springs and multiplies at rather high temperatures - above 45 degrees. Entire colonies of these microorganisms have been identified in various geothermal zones of our planet,such as the waters of hot natural springs. Thermophilic bacteria survive due to the presence in them of special enzymes that can function at high temperatures. For them, the most favorable temperature regime is a corridor of 50-65 degrees. Under such conditions, bacteria can feel comfortable and freely multiply.
Many people would like to know at what temperature thermophilic bacteria die in order to control their number. In this regard, I would like to note that scientists have not yet been able to obtain accurate data on this. At the present stage of development of science, it is only known that the maximum temperature indicator for thermophiles is 68-75 degrees. However, this does not mean that bacteria die with such heating - a deviation from the optimal regime makes their life less comfortable and intense, slows down cell growth and reduces the rate of metabolic processes.
Is it possible to kill bacteria? What is affecting them?
In order for thermophilic bacteria to die, a much greater excess of the upper threshold is needed. Today, scientists have been able to establish that the highest known temperature at which these microorganisms can live is 122 degrees Celsius. It is not possible to create higher heating in laboratory conditions. Therefore, it is not yet possible to establish at what temperature thermophilic bacteria will die. It is only known that sharp fluctuations in temperature have a very detrimental effect on the life of bacteria: the development of a culture may stop, butwill she die is the question.
Varieties and their descriptions
Assessing the temperature preferences of microorganisms, they can be divided into three main groups: psychrophilic, mesophilic and, in fact, thermophilic. All of them are dependent on heat, but differ in terms of temperature regimes.
Thus, psychrophilic bacteria are the least thermodependent and prefer the temperature range from zero to +10 degrees. This is the optimal development corridor for them, but they can breed both at -5 degrees and at +15.
Next - mesophilic thermophilic bacteria, the comfort zone for which is located between 30 and 40 degrees Celsius. Bacteria may well grow and multiply when the temperature drops to 10 degrees or rises to 50 degrees. The optimal level for growth in these organisms is 37 degrees.
And finally, thermophilic bacteria - their active growth is observed when the temperature reaches above 50 degrees. Their main distinguishing feature is the accelerated rate of metabolism. According to recent studies, it has been established that under the influence of temperature there are significant changes in proteins and lipids, which play a major role in all life processes.
Subgroups of thermophiles
A vivid illustration of this are examples of thermophilic bacteria, which are also divided into several independent subgroups:
- Extreme thermophiles with an optimal temperature of 80 degrees with a minimum of 60 and a maximum of 105 degrees.
- Stenothermophiles, or facultative, with a range of 55-65 degrees, but show the ability to reproduce even when the temperature drops to 20 degrees. The highest ability to grow is observed at 20-40 degrees.
- Eurythermophiles prefer 37-48 degrees. The peculiarity of obligate thermophiles is that they do not lose their ability to grow even at 70 degrees, but they do not grow below 40 degrees.
- Thermotolerants with an optimal indicator not higher than 48 degrees, the minimum temperature at which they can grow is 10 degrees, and the maximum is 55-60. They differ from mesophiles at the same optimal temperatures in that as the temperature threshold increases, bacteria continue to grow.
Anaerobic thermophiles
The ability of the rapid growth of thermophilic organisms gives them an excellent opportunity to be used in various areas of life - in industry or in agriculture, and even at the household level. At the same time, mesophilic and thermophilic lactic acid bacteria have similar isolation methods. The difference is observed only in growing temperatures. To establish the exact optimal temperature level, the culture must be passivated for one or two months, or, in other words, reseeded in a certain temperature range.
In nature, many types of thermophilic bacteria are widespread and live in various conditions. They love warmth and feel very comfortable in the human stomach, and can also be found in animals, plants, soil, water and various other environments,providing favorable conditions for development. Some bacteria require air to grow, while others do not need oxygen at all. According to this sign of dependence on oxygen, thermophilic organisms are divided into aerobic and anaerobic.
Anaerobic include several separate groups:
- Butyric - during fermentation, they produce butyric acid, feed on sugar, pectins, dextrins, and produce acids - acetic and butyric, as well as hydrogen and carbon dioxide. Of the useful properties, the production of acetone, ethyl, butyl and isopropyl alcohols can be distinguished. Found in thermophilic and mesophilic forms.
- Cellulose live in river silt, compost, plant residues. These thermophilic compost bacteria are ideal and widely used in the agricultural sector. Being in the soil or humus, these bacteria gain activity at 60-65 degrees. There is also a mesophilic form - Omelyansky's stick. These bacteria, with the help of a special enzyme, decompose cellulose, releasing carbon dioxide, hydrogen, ethyl alcohol, a number of acids - formic, acetic, fumaric, lactic and other organic acids.
- Methane-forming live in the same place as cellulose, and cultivated there. In this group, the most studied species are methanobacterium and methanobacillus. They are not capable of sporulation, and their usefulness lies in the ability to produce antibiotics, vitamins, enzymes, using sewage and household waste for food.
- Desulfurizers are most often found next tocellulose and live off the reduction of sulfates. They have oval spores that are located closer to one of the ends of the bacillus bacillus - terminal or subterminal.
- Lactic acid - a special large group of bacteria that live in milk. These thermophilic lactic acid bacteria can be both beneficial to humans and very harmful. Some of their species can synthesize special aromatic substances. It is they who, after exposure to milk, give a pleasant taste and aroma to cottage cheese or cream. Such thermophilic lactic acid bacteria are facultative anaerobic, therefore they can optimally multiply in the absence of oxygen or in an environment where there is a large deficit of it.
Lactic acid
Lactic acid bacteria are divided into cocci and rods. The former consist of several cells connected in a chain - streptococci and have homo- and heterogeneous fermentation. Homofermentative streptococci ferment the sugar found in milk to make live yogurt. Heteroenzymatic in parallel also secrete such aromatic substances as diacetin and cytoin. Their cells are round or oval in shape, stain well according to Gram and do not form spores and capsules. They are aerotolerant and can exist in the presence of air. However, they lack the ability to carry out aerobic respiration, and they prefer to continue their usual process of lactic acid fermentation. In order to eat, they need a lot of vitamins, proteins, organic acids. in milkbacteria cause its coagulation, the formation of a dense, even clot with a small amount of serum. It is thanks to the aroma-producing lactic streptococci that seductive bubbles appear in the cheese with a characteristic odor and low ability to form acids. Cocci are highly alcohol resistant and require high acidity.
Lactic acid sticks
Lactic acid sticks - they are otherwise called lactobacilli - can be either single or paired. Most often, acidophilic lactobacilli are used, especially the Bulgarian stick, which is part of the starter cultures and makes it possible to produce tasty and he althy yogurt. Even in the dairy industry, streptobacteria and beta bacteria are popular. These organisms are completely immobile and do not form spores or capsules, they stain well by Gram.
Lactic acid thermophiles are facultative anaerobes. They can become monoenzymatic, with a high rate of acid formation, or hereroenzymatic with the ability to process fructose in parallel, resulting in the formation of hexahydric alcohol mannitol, acetates, lactates and carbon dioxide. Proteins are rather weakly processed, therefore, in order to grow, they require the presence of amino acids in the environment. Some sticks have the ability to produce catalase, an enzyme that breaks down hydrogen peroxide, or acetaldehyde, which gives flavor and aroma to cheese.
Lactic acid heat-resistant sticks can survive in milk when pasteurized at a temperature of 85-90 degrees. They are very resistant to disinfecting agents and thus cause considerable harm to food enterprises. They are Escherichia coli antagonists. Found in sourdough or low pasteurized milk.
Thermophiles who can't breathe without oxygen
Aerobic thermophiles, which cannot breathe without oxygen, are also divided into two separate groups:
- Extreme thermophilic - gram-negative rods that are not able to move, related to obligate bacteria, the growth of which occurs at an optimal temperature of 70 degrees. As the temperature rises higher, the sticks transform into thin threads. Live en masse in hot water springs and nearby soil.
- Spore-forming forms are similar to mesophilic ones. Live and spread in well loosened soil or aerated waters.
Having considered all these types of microorganisms, it should be noted that the appearance of thermophilic bacteria is their aromorphosis into the habitat. Like other living organisms, bacteria can also perfectly adapt to changes in environmental conditions in the course of their evolution. At the same time, they significantly increase the level of their organization and acquire new abilities.
Benefits and harms
What are the harms and benefits of thermophilic bacteria? Lactic acid sticks used in the food industry bring undoubted benefits to a person. Being part of various starter cultures, they produce tasty anduseful lactic acid products that have a very positive effect on all systems of the human body, help regulate metabolic processes, normalize the digestive tract and in every possible way help protect the body from various putrefactive bacteria, cleansing it in parallel from accumulated toxins and toxins. In addition to improving the composition of the microflora, thermophilic bacteria calm the nervous system, suppress the action of antibiotics and increase immunity.
In addition to the food industry, this type of bacteria is used quite widely in the pharmacological and cosmetic fields. On their basis, various probiotics are made, as well as cosmetics that give the skin grooming and elasticity, and are also used to whiten and restore it. Live yogurt masks can work wonders.
Thermophilic and mesophilic bacteria that live in soil and compost help recycle organic matter, fertilizing the soil for good plant growth. The emitted methane can be successfully used for heating houses and industrial facilities. With such a huge scale of benefit, the little harm that thermophilic rods deliver to food industries is leveled by exposure to bactericidal drugs and constant monitoring of food production equipment.
Conclusion
In this article, we gave the basic concepts of such a large and little-studied class as bacteria. It follows from the above material that thermophilic bacteriaalready today are widely used by man for his own good. But this process is far from over, and many more pleasant and useful discoveries await us.
