What are the useful bacteria?

Foaming kvass, soft spongy bread - we would not have tried them, if not for our friends - microorganisms. Let's find out together, what are the useful bacteria?

The kid has already undoubtedly turned his attention to the multi-colored mold spots, miraculously "flourishing" on a forgotten crust of bread or in a jar of jam.

For crumbs, it really can seem a miracle: yesterday the bread slice looked quite ordinary, and today ... covered with gray, yellow, blue spots! "What it is? Where did it come from? Is it possible to eat such bread? "- asked a little pokachka, or maybe it started not with mold, but with illness:" In the evening I was perfectly healthy, but today? " Or the little one saw his mother roll out the yeast dough: "Why does it squeak under the rolling pin? And why does it get out of the package? And who made holes in the test? "Children can not wait to learn everything!

And really, what do we really know about these and other microorganisms that surround us every day?


Debunking Myths

Most people are sure that from microbes - one harm and they should be striven to destroy by all available means: from washing hands with antibacterial soap and ending with the treatment of each square centimeter of the apartment with chlorine-containing agents. Someone even gets ultraviolet lamps for the children's room, rather rubbing their hands: "Well, now hold on! As in the hospital there will be: cleanliness and sterility! "But, meanwhile, scientists have long known - microbes, or, as they are more correctly called, microorganisms, are everywhere, so that it is useless to struggle with them. your own organism.

Sometimes every mother asks herself what kind of beneficial bacteria are and what is more useful for the child. Moreover, without microorganisms, life on Earth would not have been possible at all!

The global cycle of substances occurs precisely with their active participation: if these small toilers once disappeared, the planet would very quickly be buried by the remnants of dead plants and dead animals. They return to the soil once the mineral substances "taken out" from it by the plants, thus regulating its fertility, and the food products that are on our table daily?

But this again the microorganisms worked: drank the milk in a variety of sour-milk products, made bread from the yeast dough lush, better baked and easily assimilated, preserved for us pickled and pickled products, took care of even our leisure, making alcoholic beverages, tried to provide us with delicacies - for example, cheeses with noble mold "Roquefort" and "Camembert". Culinary specialists use citric acid extracted from molds (which also belong to the microworld), agronomists - bacterial preparations for combating diseases and pests of cultivated plants, zootechnicians prepare nutritious and long-stored feeds for farm animals (such as silage), pharmacists - a variety of antibiotics , vaccines, enzymes, vitamins ... We are confronted with the end products of microbial activity several times a day, without even thinking about it.


And the invisible companions living on us and in us? Of course, there are unexpected visitors, but most of them are included in the honorary club "Normal human microflora": microorganisms in many places inhabit the skin and mucous membranes, but most of all microbes live in the intestines, where they work for the good of the human body.Some produce enzymes, helping to more fully absorb the nutrients from the incoming food, others produce vitamins, which are absorbed by the wall of the intestine and are used by the host organism of this whole brethren. The third (acidophilic and bifidoba terii, as well as E. coli) have antibiotic (m. e. suppressing life activity) properties relative to putrefactive and pathogenic microbes.

Now you understand what are the useful bacteria and why is it important to use sour-milk products, especially with the prefix "Bio" in the name (they contain, in addition to the usual lactic acid bacteria, bifidobacteria)? Those of them who will reach intestine safely (and many will succeed), will remain there and temporarily take root for the benefit of man.


A spoon of tar

However, not everything is so radiant. Like any creature in nature, the microbes are different and do not fall under the definition of "absolutely harmful" or "absolutely useful." You can not discount the various and often dangerous infectious diseases - again they are the blame, invisible microorganisms. Of course, scientists have learned to fight with many of them - in some places even a planetary victory has been won, with some concluded a temporary truce (for example, leprosy, or, as it is called otherwise, leprosy, the number of cases in the world decreases every year, but so far it is premature to speak of a person's victory over a disease). Other pathogens of infection pose a serious danger so far, despite the current level of development of medicine - for example, tuberculosis. And new diseases appear with sad regularity: remember at least AIDS or swine flu (although many of them can be called new only conditionally - most often this is a long-known science, but now a mutated microbial with new properties).


In addition to the fact that microorganisms cause various infectious diseases, many of them cause human and other damage - for example, lead to spoilage of food. And often these are the same friends: lactic acid bacteria ferment fresh milk; yeasts lead to fermentation and souring of juices and fruits; mold ... However, with mold everything is clear. Fortunately, a person has learned to deal with this kind of trouble - no wonder now there are many ways of preserving and sterilizing products: from banal boiling to ultrasound treatment, from simple drying to applying chemical preservatives, increasing the shelf life several times or even an order of magnitude.


Who should be afraid

To protect yourself from really harmful microbes and make friends with useful (or harmless) ones, it is enough to observe simple, well-known rules: wash hands before meals and after visiting the toilet, after returning home from anywhere, wash vegetables bought at the market or in the store and fruit, monitor the shelf life of products, during epidemics, limit contact with possible carriers of infection. And in general, the general rules of hygiene and sanitation have not been canceled yet, but it seems superfluous to ubiquitous and regular destruction of microbes at home. There are several reasons for this. Firstly, as it was said, bacteria and spores of mold fungi are everywhere, therefore the use of the treatment is not very long. Secondly, not only harmful microbes are exposed to destruction, but all the rest (useful and indifferent to the organism), and scientists have already proved that regular meetings with representatives of the microworld are necessary for the formation of normal immunity to the child. And, thirdly, disinfectants are usually quite aggressive substances, which act not only on microorganisms, but also on pets and humans.


Let's play with the baby

We will play in scientists-microbiologists, who put various experiments on microorganisms. It is clear that the microscope is not in every house, and even if there is, then the bacteria even with it is not easy to see - we need special tools, dyes ... However, the microbes are so good that they themselves are difficult to see, but their works - please !! First, explain to the baby what microbes are, where they live, what they do, why we do not see them. And then start studying the fascinating and diverse microcosm! Just remember that some experiments are designed for very young, and others - are available to the understanding of already grown up children.


Why did the milk turn sour?

Carry out a simple experiment - pour in different cups of different milk: sterilized (with a long shelf life), pasteurized (also purchased) and boiled (you can boil and pasteurized milk). If possible, you can add home milk that has not been heat treated. Let the kid follow the experiment on his own: every day he checks the condition of the "experimental subjects." For an older child, it may be interesting to keep a "Diary of Observations" - just like real scientists!

At the end of the study, the baby should make a conclusion - which milk quickly sour? Why? In turn, parents should explain what caused the fermentation (lactic acid bacteria are the same as in all fermented milk products sold in the store), where the bacteria came from (normally these bacteria are always present in the milk, they get there from the surface feeds, herbs fed by cows), how to prevent the spoilage of milk (for this milk is first heated at a certain temperature (about 60-80 C) and then cooled quickly), why the milk must be stored in a cool place (in the refrigerator, the development of all bacteria slows down, so the milk does not sour for longer).


How many holes are there in the test?

The kid is probably interested in knowing who made so many holes in the bread. To illustrate clearly the process of alcohol fermentation (namely this phenomenon is caused by special microscopic fungi - yeast and leads to loosening of the dough), suggest that the child together with you repeat all the way that passes the bread before you get to us on the table. Knead the dough with the addition of yeast, let it brew (at this time the yeast multiplied to the required level and proceeds to process the sugar contained in the flour into alcohol and carbon dioxide) and bake. Alcohol in the process of baking will evaporate, and the gas bubbles will turn into those most amusing holes.

In general, with yeast, you can conduct many exciting experiments. For example, knead the same lumps of dough, but with the addition of different yeast - dry, moist pressed or homemade, and compare which dough will rise faster. The results can be used by the mother with the next batch of home-made bread. You can experiment with the composition: add more sugar, butter or milk, and take the yeast the same and check what kind of dough the yeast reproduces better. You can study the effect of temperature on the speed of the dough rise: put the kneaded dough pieces into heat (on the battery, near the stove), in the cold (on the window or in the refrigerator) and leave at room temperature. All the experiments carried out will clearly help the girls - future housewives! - to understand and memorize the basic conditions of the right kneading of the yeast dough, and to the boys - to the inquisitive experimenters - to inconspicuously join the help of the mother in the kitchen.


"Velvet" on sour cream

On the surface of many sour-milk products (often sour cream or yogurt) after a long storage, you can sometimes see a beautiful white-cream velvet coating. This is again the microorganisms familiar to us - mold fungi, more precisely, their representative - milk mold. In contrast to fermented milk bacteria, milk mold, if introduced into the product, is not edible. Therefore, admire the natural "velvet" and discard the product without regret.


Who lives in kvass?

For the experience, an old kvass or beer, one condition: kvass should be natural, that is so-called live fermentation.

Nothing special to do with it is not necessary - just pour into a container and put in the kitchen on the table. Do not close the lid tightly. Over time, a thin film is formed on the surface of kvass, consisting of a number of acetic acid bacteria. Simultaneously, a characteristic smell of acetic acid appears and over time. Explain to the kid that these bacteria like oxygen, which is contained in the air, and therefore float on the surface, and do not sink to the bottom; they processed the alcohol contained in kvass, into the smelling acetic acid.


Why does not the egg spoil?

Experience can be conducted after you pay attention to the child's widespread in nature and life phenomenon - the spoilage of products. Everything that happens on our table, one way or another, sooner or later undergoes spoilage - it saps, rotes, molds. All, but not all! And without the use of chemical preservatives, you can find amazing products, protected from spoilage by nature itself - onion, garlic, honey, egg ...


That's the last and will be discussed. Invite a young scientist to break a chicken egg, separate the yolk and conduct an experiment on the raw protein. You need to pour it in some dishes and for comparison, put a different product in the same container, for example milk. The baby needs to wait until the protein starts to deteriorate. When will this happen? If the chicken that carried the egg was healthy, it would never - the protein, rather, simply dry, than it begins to rot. And special substances help him in this, the most important of which is lysozyme (which, by the way, is in the human body - is contained in saliva and tear fluid), which protects the contents of the egg from bacteria.

Perhaps, this experience will convince, at last, a small nehochuhu to eat a useful testicle? In a word, make friends with the microbes themselves and teach this to your baby - it's fun and useful. Encourage the child to enjoy the science from early childhood!