Natural water is precisely the environment where numerous microorganisms intensively multiply, and therefore the microflora of water will never cease to be the object of close attention of a person. How intensively they reproduce depends on many factors. In natural water, mineral and organic substances are always dissolved in one or another amount, which serve as a kind of "food", thanks to which the entire microflora of water exists. In terms of quantity and quality, the composition of micro-habitats is very diverse. Almost never can be argued that this or that water, in one or another source - is pure.
Artesian water
Key or artesian waters are underground, but this does not mean that microorganisms are absent in them. They are necessarily there, and their composition depends on the nature of the soil, soil and the depth of a given aquifer. The deeper - the microflora of water is poorer, but this does not mean that it is completely absent.
The largest amount of bacteria is found in ordinary wells, which are not deep enough to prevent surface contamination from leaking into them. It is there that pathogens are most often found. And the higher the groundwater, the microflora of the water is richer and more abundant. Almost all closed reservoirs are excessively saline, as salt has accumulated underground for many hundreds of years. Therefore, most often before drinking artesian water is filtered.
Surface water
Open reservoirs, that is, surface waters - rivers, lakes, reservoirs, ponds, swamps and so on - have an unstable chemical composition, and therefore the composition of microflora there is very diverse. This is because every drop of water is contaminated with household waste, and often industrial waste, and the remains of rotting algae. Rain flows flowing here, bringing a diverse micro-life from the soil, sewage from factory and factory production also falls here.
Along with all kinds of mineral and organic pollution, reservoirs also take in 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 one hundred cells of bacteria, in a liter - no more than three cells of E. coli.
Pathogens
Such water under a microscope presents the researcher with a number of pathogens of intestinal infections, which are kept virulent for quite some time. For example, in ordinary tap water, the causative agent of dysentery is viable for up to twenty-seven days, typhoid fever - up to ninety-three days, cholera - up to twenty-eight. And in river water - three or four times longer! Typhoid fever threatens the disease one hundred eighty-three days!
The pathogenic microflora of water is carefully monitored, and in case of need, quarantine is even declared - with the threat of an outbreak. Even sub-zero temperatures do not kill most microorganisms. A frozen drop of water stores quite viable bacteria of the typhoid group for several weeks, and this can be verified using a microscope.
number
The number of microbes and their composition in an open reservoir directly depend on the chemical reactions taking place there. The microflora of drinking water is very high with a close population of coastal areas. At different times of the year, it changes its composition, and there are also 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 are for the most part rod-shaped bactenias indisputable.
Near industrial enterprises or large settlements in a cubic centimeter of river water, many hundreds of thousands and millions of bacteria. Where civilization is almost absent - in taiga and mountain rivers - water under a microscope shows only hundreds or thousands of bacteria in the same drop. In stagnant water, microorganisms, of course, are much larger, especially near the coast, as well as in the upper layer of water and in the silt at the bottom. Sludge is a nursery for bacteria, from which a kind of film is formed, due to which most of the processes of transformation of substances of the whole body of water take place and the microflora of natural waters is formed. After heavy rains and spring floods, the number of bacteria also increases in all reservoirs.
"Bloom" of a reservoir
If aquatic organisms begin to develop in large quantities, this can cause quite significant harm. Microscopic algae multiply rapidly, which leads to the process of the so-called flowering of the reservoir. Even if such a 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 are some types of blue-green algae: it causes many irreparable troubles from death of cattle and poisoning of fish to serious diseases of people. Together with the "flowering" of water, conditions are created for the development of a variety of microorganisms - protozoa, fungi, viruses. Together, all this is microbial plankton. Since the microflora of water plays a special role in human life, microbiology is one of the most important fields of science.
Aquatic environment and its types
The qualitative composition of microflora depends directly on the origin of the water itself, on the habitat of microscopic organisms. There are fresh waters, surface ones - rivers, streams, lakes, ponds, reservoirs, which have a characteristic microflora composition for them. In the underground, as already mentioned, depending on the depth, the number and composition of microorganisms varies. There are atmospheric waters - rain, snow, ice, which also contain certain microorganisms. There are salty lakes and seas, where, accordingly, there is a microflora inherent in such an environment.
Also, water can be distinguished by the nature of use - it is drinking water (local or centralized, which is taken from underground sources or from open reservoirs. Water of swimming pools, household, food and medical ice. Wastewater requires special attention from the sanitary side. They are also classified: industrial, household-fecal, mixed (of the two types listed above), storm and thawed. Wastewater microflora always pollutes natural water.
The nature of microflora
The microflora of water bodies is divided into two groups depending on the given aquatic environment. These are their own - autochthonous aquatic organisms and allochthonous organisms, that is, those that come from external pollution. Autochthonous microorganisms that constantly live and multiply in water resemble the microflora of the soil, coastal or near-bottom, with which water comes into contact. The specific aquatic microflora almost always contains Proteus Leptospira, its various species, Micrococcus candicans M. roseus, Pseudomonas fluorescens, Bacterium aquatilis com mum's, Sarcina lutea. Anaerobes in not too polluted water bodies are represented by the species Clostridium, Chromobacterium violaceum, B. mycoides, Bacillus cereus.
Allochthonous microflora is characterized by the presence of a combination of microorganisms that remain active for a relatively short time. But there are more tenacious, long-term polluting water and threatening the health of humans and animals. These are the causative agents of subcutaneous mycoses Clostridium tetani, Bacillus anthracis, some species of Clostridium, microorganisms that cause anaerobic infections - Shigella, Salmonella, Pseudomonas, Leptospira, Mycobacterium, Franciselfa, Brucella, Vibrio, and enteroviruses. Their number varies quite widely, because it depends on the type of reservoir, on the season, weather conditions and the degree of pollution.
The positive and negative value of microflora
The cycle of substances in nature significantly depends on the vital activity of microorganisms in water. They break down organic matter of plant and animal origin, provide nutrition to all living in water. Contamination of water bodies is most often not chemical, but biological.
The waters of all surface reservoirs are open for microbial contamination, i.e. contamination. Those microorganisms that enter the reservoir along with sewage, melt, storm water can dramatically change the sanitary regime of the area, since the microbial biocenosis itself changes. These are the main pathways for microbial contamination of surface waters.
The composition of the microflora of wastewater
The microflora of wastewater contains the same inhabitants as in the intestines of humans and animals. It includes representatives of both normal and pathogenic flora - tularemia, pathogens of intestinal infections, leptospirosis, yersiniosis, hepatitis viruses, poliomyelitis and many others. Bathing in a pond, some people infect water, while others become infected. This also happens when rinsing clothes, when bathing animals.
Even in the pool where the water is chlorinated and purified, BGKP bacteria are found - groups of Escherichia coli, staphylococci, enterococci, neisseria, spore-forming and pigment-forming bacteria, various fungi and microorganisms like viruses and protozoa. Bacterial carriers that bathe there leave Shigella and Salmonella. Since water is not a very favorable environment for reproduction, pathogenic microorganisms take the slightest opportunity to find for themselves the main biotope - the organism of an animal or a person.
Not so bad
Ponds, like the great and mighty Russian language, are capable of self-purification. The main way is competition, when the saprotyphic microflora is activated, which decomposes organic substances and reduces the number of bacteria (especially successfully of fecal origin). The constant species of microorganisms that make up this biocenosis are actively fighting for their place in the sun, leaving the aliens not an inch of their space.
The most important thing here is the qualitative and quantitative ratio of microbes. It is extremely unstable, and the impact of various factors greatly affects the state of water. Saprobity is important here - a set of features that a particular body of water possesses, that is, the number of microorganisms and their composition, the concentration of organic and inorganic substances. Typically, the self-purification of a reservoir occurs sequentially and never interrupts, whereby biocenoses gradually change. Pollution of surface waters is distinguished in three gradations. These are oligosaprobic, mesosaprobic and polysaprobic zones.
Zones
Zones of particularly severe pollution - polysaprobic - are almost free of oxygen, since a huge amount of easily decomposing organic matter takes it. Microbial biocenosis is correspondingly very large, but limited in species composition: mainly anaerobic bacteria, fungi and actinomycetes live there. One milliliter of such water contains more than a million bacteria.
The zone of moderate pollution - mesosaprobic - is characterized by the dominant nitriation and oxidation processes. The composition of the bacteria is more diverse: obligate aerobic, nitrifying bacteria make up the majority, but with the presence of species Candida, Streptomyces, Flavobacterium, Mycobacterium, Pseudomonas, Clostridium and others. In one milliliter of this water is not millions, but some hundreds of thousands of microorganisms.
The clean water zone is called oligosaprobic and is characterized by a self-cleaning process that has already ended. There is a small amount of organic matter and the mineralization process 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.