Microflora of water. A drop of water under a microscope. Composition of water

Natural water is precisely the environment where numerous microorganisms multiply intensively, and therefore the microflora of water will never cease to be the object of close attention of a person. How much they multiply, depends on many factors. In natural water, mineral and organic substances are always dissolved in one or another quantity, which serve as a kind of "food", thanks to which the whole microflora of water exists. In terms of quantity and quality, the composition of microbiota is very diverse. It is almost never possible to assert that a particular water, in one or another source, is pure.

Artesian water

Key or artesian water is underground, but this does not mean that there are no microorganisms in them. They necessarily exist, and their composition depends on the nature of the soil, soil and depth of occurrence of this aquifer. The deeper - the microflora of water is poorer, but this does not mean that it is completely absent.

The most significant amount of bacteria is contained in ordinary wells, which are not deep enough that they do not penetrate surface contamination. It is there that the pathogenic microorganisms are also found most often. And the higher the groundwater is, the more microflora of water is richer and more abundant. Almost all closed reservoirs are excessively saline, since salt accumulated underground for many hundreds of years. Therefore, most often before use, artesian water is filtered.

Surface water

Open reservoirs, that is, surface waters - rivers, lakes, reservoirs, ponds, swamps, etc. - have a variable chemical composition, and therefore the microflora composition there is very diverse. This is because each drop of water is contaminated with domestic, and often industrial waste, and the remains of rotting algae. Here rainwater flows, bringing a diverse micro-life from the soil, and sewage of factory and factory productions also enter here.

Simultaneously with all kinds of mineral and organic pollution, the reservoirs take on themselves huge masses of microorganisms, including pathogens. Even for technological purposes, water is used that meets GOST 2874-82 (in one milliliter of such water there should not be more than a hundred cells of bacteria, in liter - no more than three cells of Escherichia coli.

Pathogens diseases

Such water under a microscope presents to the researcher a whole series of causative agents of intestinal infections, which for quite a long time remain virulent. For example, in ordinary tap water, the causative agent of dysentery is viable up to twenty-seven days, typhoid fever - up to ninety-three days, cholera - up to twenty-eight. And in the river water - three or four times longer! Abdominal typhus threatens with disease one hundred eighty three days!

The pathogenic microflora of water is carefully monitored, and in case of need, even quarantine is declared - in case of an outbreak of the disease. Even minus temperatures most microorganisms do not kill. A frozen drop of water keeps the viable bacteria of the typhoid group for several weeks, and this can be verified using a microscope.

amount

The number of microbes and their composition in an open reservoir directly depend on the chemical reactions occurring there. Very much increases the microflora of drinking water with close settlement of coastal areas. At different times of the year, it changes its composition, and there are many other reasons for changes in one direction or another. The cleanest reservoirs contain up to eighty percent of coccal bacteria among all microflora. The remaining twenty - for the most part rod-shaped bactenes are spontaneous.

Near industrial enterprises or large settlements in the cubic centimeter of river water are many hundreds of thousands and millions of bacteria. Where there is almost no civilization - in taiga and mountain rivers - water under a microscope shows only hundreds or thousands of bacteria in the same drop. In the standing water of microorganisms, naturally, there are many more, especially near the shores, as well as in the upper layer of water and in the ooze at the bottom. Il is a nursery for bacteria, from which a unique film is formed, due to which most of the processes of transformation of the substances of the whole body occur and the microflora of natural waters is formed. After abundant downpours and spring flood, the number of bacteria also increases in all water bodies.

"Flowering" of the reservoir

If aquatic organisms begin to develop massively, this can cause considerable harm. Microscopic algae are rapidly multiplying, which causes the process of so-called flowering of the reservoir. Even if this phenomenon is small in scale, the organoleptic properties deteriorate sharply, even filters at waterworks can fail, the composition of the microflora of water does not allow it to be considered drinking.

Particularly harmful in the mass development of some species of blue-green algae: it causes many irreparable troubles from the death of livestock and poisoning of fish to severe human diseases. Together with the "flowering" of water, conditions are created for the development of various microorganisms - protozoa, fungi, viruses. Together, all this is microbial plankton. Since the microflora of water play a special role in human life, microbiology is one of the most important fields of science.

Water environment and its types

The qualitative composition of the microflora depends directly on the origin of the water itself, from the habitat of microscopic organisms. There are fresh waters, surface waters - rivers, streams, lakes, ponds, reservoirs, which have a characteristic microflora composition. In underground, as already mentioned, depending on the depth of occurrence, the amount and composition of microorganisms varies. There are atmospheric waters - rain, snow, ice, which also contain certain microorganisms. There are saline lakes and seas, where, accordingly, there is a peculiar microcloflor environment.

Also, water can be distinguished by the nature of the use - it is drinking water (local water supply or centralized, which is taken from underground sources or from open reservoirs.) The water of swimming pools, the ice is economic, food and medical.Several attention from the sanitary side requires wastewater, they are also classified: Industrial, domestic-faecal, mixed (the two types listed above), storm and thawed. The microflora of sewage always pollutes the natural water.

Nature of microflora

The microflora of water bodies is divided into two groups depending on the given aquatic environment. These are own - autochthonous aquatic organisms and allochthonous, that is, falling into the contamination from the outside. Constantly living and multiplying in the water autochthonous microorganisms in composition resemble the microflora of the soil, coastal or near-bottom, with which water contacts. The specific aquatic microflora contains almost always Proteus Leptospira, its various species, Micrococcus candicans M. roseus, Pseudomonas fluorescens, Bacterium aquatilis com mum's, Sarcina lutea. Anaerobes in not too polluted reservoirs are represented by species of Clostridium, Chromobacterium violaceum, B. mycoides, Bacillus cereus.

Allochthonous microflora is characterized by the presence of a combination of microorganisms that retain activity for a relatively short time. But there are also more tenacious, long-term polluting water and threatening the health of humans and animals. These are the causative agents of the subcutaneous mycoses Clostridium tetani, Bacillus anthracis, some Clostridium species, microorganisms that cause anaerobic infections - Shigella, Salmonella, Pseudomonas, Leptospira, Mycobacte-rium, Franciselfa, Brucella, Vibrio, and the virus of the lizard and enteroviruses. The number of them varies quite widely, because it depends on the type of reservoir, season, meteorological conditions and degree of pollution.

Positive and negative importance of microflora

The cycle of substances in nature depends on the vital activity of microorganisms in the water. They split organic substances of vegetable and animal origin, provide food for all living in water. Pollution of water bodies is often not chemical, but biological.

The waters of all surface reservoirs are open to microbial contamination, that is pollution. Those microorganisms that enter the reservoir along with sewage, thawed, storm water can dramatically change the sanitary regime of the terrain, as the microbial biocenosis itself changes. These are the main ways of microbial contamination of surface waters.

Composition of sewage microflora

The microflora of sewage contains the same inhabitants as in the intestines of humans and animals. There are representatives of both normal and pathogenic flora - tularemia, causative agents of intestinal infections, leptospirosis, iersiniosis, hepatitis viruses, poliomyelitis and many others. Bathed in a pond, some people infect water, and others become infected. This also happens when rinsing the laundry, while bathing animals.

Even in the pool, where the water is chlorinated and purified, bacteria CGB - colibacillus groups, staphylococci, enterococci, Neisseria, spore-forming and pigment-forming bacteria, various fungi and microorganisms such as viruses and protozoa are detected. Bacteria, swimming there, leave after themselves shigella and salmonella. Since water is not a very favorable breeding ground, pathogenic microorganisms use the slightest opportunity to find for themselves the main biotope - the animal or human organism.

Not so bad

Ponds, like the great and mighty Russian language, are capable of self-cleaning. The main path is competition, when the saprophytic microflora is activated, which decomposes organic substances and reduces the number of bacteria (especially faecal origin). Constant species of microorganisms that are part of this biocenosis, actively fight for their place under the sun, leaving no aliens a span of their space.

Here the most important is the qualitative and quantitative ratio of microbes. It is extremely unstable, and the impact of various factors strongly affects the state of water. It is important saprobity - a complex of features that this or that reservoir has, that is, the number of microorganisms and their composition, the concentration of organic and inorganic substances. Usually the self-purification of the reservoir occurs consistently and is never interrupted, whereby the biocenoses gradually change. Contamination of surface water is distinguished in three grades. These are oligosaprobic, mesosaprobic and polysaprobic zones.

Zones

Areas of particularly severe pollution - polysaprobic - are almost without oxygen, as it takes away a huge amount of easily decomposable organic matter. Microbial biocenosis, respectively, is very large, but limited in species composition: there live mainly anaerobic bacteria, fungi and actinomycetes. One milliliter of this water contains more than a million bacteria.

The zone of moderate pollution - mesosaprobic - is characterized by a dominant nitrification and oxidation processes. The composition of bacteria is more diverse: obligate aerobic, nitrifying bacteria make up the majority, but with the presence of species of Candida, Streptomyces, Flavobacterium, Mycobacterium, Pseudomonas, Clostridium and others. In one mililiter of this water is no longer millions, but some hundreds of thousands of microorganisms.

The zone of pure water is called oligosaprobic and is characterized by the already completed self-cleaning process. There, a small amount of organic matter and the process of mineralization is completed. The purity of this water is high: in a milliliter it is not more than a thousand microorganisms. All pathogenic bacteria have already lost their viability there.