Guide of microbiologist

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Actinomycetes (from the Greek aktis — ray and myces — fungi) – ray fungi with unicellular nonseptate mycelium. They do not have a differentiated core and the fruiting bodies.

Actinomycins highly toxic polypeptide antibiotics, which have a characteristic red color. They are produced by actinomycetes of different types.

Actinophages viruses, which hosts are actinomycetes.

Adaptation (from lat. Adaptation - adaptation) — adaptation of microbial cells to any factors showing its effect in the external environment. Adaptation may be accompanied by the appearance of temporary non-inheritable changes

Adaptive immunity — immunity, transferred to nonimmune recipient's body using immune cells of the donor.

Aerobic (fro(from the Greek aer - air and bios — life) — microorganisms that use atmospheric oxygen as the final electron acceptor (hydrogen) in biological oxidation,

Agar-agar the polysaccharide contained in seaweed (Gelideum). Used in pure form for solid medium preparation. Able to form gels in water, melting at a temperature app. 100°C and solidifies at 45°C.

Allergens — ssubstances that can induce a state of allergy. Many of them possess antigenic properties (serum, tissue protein, microbial and viral antigens)

Anabolism (fro(from the Greek anabole — rise) processes of metabolism, characterized by intracellular fusion reactions, resulting in assimilation (assimilation, accumulation) of organic substances: amino acids, nucleotides, etc. Anabolism is closely linked to the catabolism, which results in the formation of the intermediate products (pyruvic acid, glycerol, etc.), entering into anabolic reactions of microbes and higher organisms.

Anaerobes (fro(from the Greek an — denial, aer — air and life) - microorganisms that can carry out metabolism and multiply in the absence of oxygen in the environment. They are divided into obligate and facultative.

Antibacterial immunity the body's resistance to bacteria.

Antibiotic-resistant (antforms of bacteria - strains of bacteria resistant to therapeutic concentrations of the antibiotic agent to which they were previously sensitive. perties of the enzyme, which is the target of the inhibitory action of the antibiotic

Antibiotics (from the Greek. (from the Greek anti — against), bio-substances of microbial origin that have the ability to delay development and cause death of various microorganisms, mainly bacteria.

Asepsis (from the Greek. a(from the Greek a - denial and septicos - purulent) - method of preventing infection of wounds, based on disinfection, i.e. the destruction of microbes and their spores in different materials using physical methods: boiling, roasting on the fire, dry heat, ultraviolet irradiation and mainly autoclaving.


Bacteria (from the Greek. bacteria (from the Greek bacteria — Bacillus) — unicellular organisms characterized by a variety of forms and a fairly complex structure that meets the diversity of their functional activity.

Bacteria spores round or oval formation formed inside bacterial cells usually under adverse environmental conditions. Aaerobic or anaerobic bacteria that form spores are called bacilli.

Bacterial toxins — biologically active substances that can cause a variety of pathological changes in the structure and function of cells, tissues, organs and the whole organism is sensitive animal or human.


Colony – microbial cell of the same species, grown up, in most cases, from a single cell in the form of isolated clusters on a dense nutrient medium.

Cultivation of microorganisms —the artificial creation of conditions for maintenance of life processes and reproduction of microbes in vitro. For this purpose nutrient media (culture) are used. To obtain microorganisms or their metabolic products on an industrial scale methods of deep and continuous cultivation are used.


Disinfection — the destrucdestruction of pathogenic microorganisms — causative agents of infectious diseases in the human environment.


Endotoxins - a poisonous substance that is closely associated with bacterial and somatic cell antigen. Allocated only after the death and destruction of bacteria. Are heat-stable lipopolysaccharide - (LPS), not inactivated with formalin.

Exotoxins — poisons produced by certain bacteria into the environment in the process of life. Have extremely high toxicity and antigenicity. Have a protein, thermolabile and neutralized formalin, while retaining its antigenic properties. The toxic mechanism of action of exotoxins often associated with inhibition of certain enzyme systems in animal cells. The most exotoxins are constantly produced by poddubitse tetanus, gas gangrene, botulism,


Fermentation — the process of dissimilation by microorganisms of organic matter, usually carbohydrates; proceeds with the liberation of energy in aerobic and in anaerobic conditions. During fermentation are formed such organic acids as lactic, formic, acetic, etc., as well as ethyl, propyl alcohols, glycerol and other substances. Types of fermentation are usually referred to as the products, which are: lactic acid, acetic acid, alcohol etc. Formed during the fermentation products and the energy consumed by microbes for various biosynthetic purposes. One type of fermentation is glycolysis (see). Many types of fermentation used in food and microbiological industries for production of alcohols, organic acids and other substances. Microbial nature of fermentation was discovered by Pasteur in 1857.


Genotype (from the Greek. race or — birth and typos — print, image)—set of genes that determine hereditary basis of all organisms, including microbes. The genotype in the phenotype


Heterotrophs (from the Greek. heteros — other, trophe — nourishment). The literal translation is "fed by others" — microorganisms metabolizing carbon from organic compounds. Such compounds can be carbohydrates, proteins, fats, as well as methane, petroleum hydrocarbons, etc. To the heterotrophs are putrefactive bacteria, fungi, yeast and other saprophytes commonly found in soil. They play a leading role in the decomposition of organic remains. To this group belong and parasites that absorb carbon not only from the dead organic remains or products of metabolism, but also from the tissues of living plants and animals. The latter include pathogenic microorganisms. The vast majority of heterotrophs get energy by oxidative processes.


Immunity (from lat. immunitas — exemption from duties) — the resistance (immunity) of the body in respect of any genetically foreign agents, including microbes and their toxins. All the mechanisms of immunity is aimed at maintaining the constancy of the internal environment of the body during the life of the individual. The origin of the immune system is divided into viduy (see) and acquired (see)

Immunization — the implementation process of natural or artificial introduction into the body of antigen. Leads to the formation of the immune system. For artificial immunization prophylactic use of vaccines and toxoids.

Incubation - maintaining the microbial system at a certain temperature and other conditions within a certain time.

Infection — the process of introduction of the infectious agent (pathogen) in a macro-organism or cells in tissue culture. Can lead to infection and latent infection or to the appearance of cytopathic effect (in tissue culture).

Inhibition (from lat. inhibitio — retention, stopping) — inhibition (full or partial) of any process by using various inhibitors.

Inhibitors (from lat. inhibitio— retention, stopping) — substances that inhibit any level in metabolism. microbial, animal or plant cells. Apply for the inhibitor-tion analysis in the study of metabolism in different microorganisms and biosynthesis of viruses. The inhibitors include antibiotics, sulfonamides and other antimetabolites, cyanide, and other compounds.


Lysogeny, lysogenic bacteria (from the Greek. lysis - dissolution — the ability of the phage to cause lysis of bacteria) is a phenomenon characterized by continuous communication between the genomes of phage and bacterial cells. In lysogenic bacteria phage DNA is integrated into bacterial chromosome. In this state it is called a prophage. Cells that carry a prophage, possess the spontaneous ability to lysis (hence the name of the phenomenon "lysogeny".), which occurs when "vysielanie" ragovoy DNA from the bacterial chromosome and its transition to the offline state. This process (induction of prophage) can be caused by various physical or chemical agents. The most common inductor is the UV irradiation of lysogenic cells. Lysogeny widely distributed among bacteria and actinomycetes. External (phenotypic) expression of such a state may be a change in hereditary traits of microbes: colony morphology, antigenic and other properties. Lysogenic cells have some selective advantages over nerisovannye, in particular, they are resistant to homologous superinfection phages. The term proposed to the Board and Ciuca in 1921


Metabolism in microorganisms (from lat. metabole –change, transformation) – intermediate transformation of substances in microbial cells. Most expressed in the logarithmic growth phase of the microbial culture.

Metabolites – compounds involved in metabolic processes.

Microbial antagonism — inhibition of the growth of one microbe to others. Is a form of relationship between organisms in associations. Antagonistic properties common to many soil spore and putrefactive bacteria, aktinomicetam, mushrooms (basically, marsupials, etc.). The mechanism of the antagonistic action of microbes may be associated with various causes: formation of toxic metabolites, antibiotics

Mushrooms – plant organisms, which are macro - and microscopic size and are characterized by the presence of a differentiated nucleus, the absence of chlorophyll and the reproduction of spores, presence of vegetative organs - hyphae that intertwine, forming a mycelium.

Mushrooms molds — mushrooms that have unicellular or multicellular mycelium differentiated fruiting bodies containing Exo - or endospores. To mold fungi include sewage fungi, Aspergillus and Penicillium. Sewage fungi are unicellular mycelium, which leaves fructiferous thread sparganosis, ending with a sporangium with endospores. Aspergillus have septate (multicellular) mycelium, condenser and conidia bearing accesory. The Penicillium from a multicellular mycelium does canadienses carrying accesory on the conidia collected in the brush.

Mutagens (mutagenic factors) — (from lat. mutatio—change and GK. genesis — development) -a substance that increases the frequency of mutations. Mutagens are a number of chemical and physical agents that may have a direct effect on DNA, its predecessors or RNA (in the case of RNA viruses). The mechanism of action of different mutagens. Part of them operates only in the synthesis of DNA, others can cause mutations, acting on resting DNA. Thus, nitrous acid will desaminase in DNA nitrogenous bases, resulting after several acts reduplication of DNA in it there is a replacement base pairs guanine-cytosine (HZ) on addintimer (AT). Hydroxylamine in the extracellular virus acts only on cytosine, leading to the replacement of HZ at AT. Athletesfoot and ethylmethanesulfonate cause alkylation of guanine and its removal from robothospital skeleton and kinks in DNA. Formaldehyde reacts with nitrogenous bases according to the amino groups, forming bridges between the bases — crosslinking. An analogue of thymine, 5-bromouracil (BU), replaces thymine phages and bacteria in the process of reduplication their DNA, which ultimately may lead to the replacement pair on at HZ or Vice versa. The so-called spermatogenic (nitrosodimethylaniline and nitrosopropane urea) alkylate cytosine, causing the replacement of thymine. They are characterized by extremely high efficiency with little lethal action, pervert the synthesis of DNA precursors will desaminase some reason. Physical mutagens are x-rays and ultraviolet rays. They have a direct damaging effect on DNA bases. In addition, a number of oxidative and destructive processes caused by free radicals produced in the environment, UV irradiation leads to the formation siminovich dimers — "cross-links" between adjacent thymine molecules. The total number sufficiently studied mutagens currently exceeds several hundreds.


Obligate parasites — microorganisms, completely lost the ability to saprophytically lifestyle and living by living cells. The highest stage of obligate intracellular parasitism is parasitism, characteristic of some pathogenic protozoan, Rickettsia, Mycoplasma, chlamydate and viruses. These microorganisms are characterized by depletion of enzyme systems up to complete loss of virus


Parasites (from the Greek. para— when

Parasites optional — microorganisms that, depending on environmental conditions behave as saprophytes

Pathogenicity (from the Greek. pathos — suffering, race or origin) is the potential ability of microbes to cause infection of macro-organisms of a certain kind. Pathogenicity characterizes the microbial species is a quality category and is determined by its genotype. Each pathogenic species microbes inherent in their own specific set of material substrates — pathogenicity factors that ensure the survival of the pathogen in the host, its reproduction or distribution in tissues and the ability for active biological influence on the functions of the microorganism. These include structural components of microbial cells, enzyme systems, bacterial endotoxins, as well as the metabolites released into the environment, and the exotoxins of the bacteria, Thus


Products of metabolism of microorganisms — include microbial enzymes, the products of decomposition of substrates of the environment, microbial toxins, antibiotic substances (see Antibiotic), pigments, bacteria, etc., Many products of metabolism

Protease (proteolytic enzymes) — a large group of enzymes that selectively or non-specific catalyses hydrolysis of peptide bonds in proteins and peptides.


Reproduction of microorganisms — binary fission unicellular microorganisms (bacteria, Rickettsia, protozoa, yeast), which results in the formation of two new subsidiaries full-fledged individuals, endowed with genetic information of the parent cell. Yeast-like fungi can multiply by budding, spores


Spores in bacteria — round or oval formation formed inside bacterial cells are usually under adverse environmental conditions, aerobic or anaerobic bacteria that form spores, called bacilli. The dispute surrounded by a two - or three-layer membrane, which is formed by the cytoplasm of the vegetative cell. The inner part of the bilayer membrane formed by the plasma disputes, which contains nucleoid. The dispute contains significantly less water than vegetative cell. Due to the shell thickness and density of the contents of the spores are very resistant to heat, drying, disinfectants, and other agents. They are impervious to most dyes. Stained spores according to the method Orzeszko or so — Nielsen.

Sterilization (from lat. sterilis— sterile) — complete destruction as vegetative forms of microorganisms and their spores. Sterilization is carried out 1) physical methods — heat air in a drying oven to 160-180° ("dry heat")

Strains (from it. stammen is to occur) culture of bacteria of the same species isolated from different sources or from one source at different times. Different strains of the same bacterial species may differ from each other on a number of properties, such as sensitivity to antibiotics, the ability to the formation of toxins, enzymes, etc.


The active immunity — the body's resistance to infectious agents or their toxins, and to any substances that have antigenic properties that occur in response to ingestion of: after the transfer of infectious diseases or as a result of "domestic" immunization with small doses of the infectious agent during prolonged contact with sick people or animals (natural active immunity). To create artificial active immunity in the body is injected vaccines and toxoids. Since the introduction of the antigen to the formation of active immunity required a latent period of approximately 7-10 days. During this period of immunological changes in the body and synthesis of specific antibodies. Formed active immunity is retained in the body from several months to several years and sometimes for life (for example, after the transfer of diseases such as measles, mumps, typhus, plague, cholera, etc.).

The aktinomitinov — highly toxic polypeptide antibiotics of nature. Have a characteristic red color. Are produced by actinomycetes of different views. The aktinomitinov are inhibitors of DNA-dependent RNA synthesis. They are mostly associated with sites of DNA rich in guanine, and particularly in areas where alternate residues of guanine and cytosine. The aktinomitinov was tested against cancer and immunodepressive operation, but clinical use is not found.

The antibacterial immunity — the body's resistance to bacteria. The specificity of antibacterial immunity associated with the formation of specific antibodies of opsonins, enhancing pagewhere reaction that leads to cleanse the body from bacteria. Antibacterial immune bodies can be detected in the reactions of agglutination, precipitation, complement fixation, opsonization.

The continuous cultivation of microorganisms — the artificial creation of conditions for maintenance of life processes and reproduction of microbes in vitro. For this purpose, use a nutrient (cultural) environment. To obtain microorganisms or their metabolic products on an industrial scale using methods of deep and continuous cultivation

The simplest (Protozoa)—single-celled animal organisms, having a differentiated nucleus, vacuoles (digestive, cardiac contractility) and various inclusions. Pathogenic protozoa are of four classes: flagellated, sarkodie, crawlers, ciliate.

The variability of the population — the variability that arises as a consequence of competitive relations in the bacterial population between individuals with different genotypes. Thus there is a selective selection of mutant individuals, the offspring will be a growing part of the population, resulting in changes of genetic structure and phenotypic properties of the population as a whole.

Toxigenicity — the ability of bacteria to produce


Vitamins — irreplaceable and limited interchangeable growth factors that use microbes for the synthesis of a number of coenzymes and cofactors (see) in several metabolic reactions. On vitamin requirements of different microoganism differ from each other. To vitamins, which often require auxotrophy (see) include: thiamin (Bi), Riboflavin (B2), Pantothenic acid (B3), nicotinic acid (B6 or PP), pyridoxal (B6), Biotin (H), lipoic acid, folic acid (Sa), paminobenzoic acid, cobamide (Bi2), zhelezodorozhni and quinones (K). Biological role of vitamins in the metabolism of microbial cells is vast and diverse. So, Riboflavin is part of flavoproteins involved in biological oxidation

Volatile antimicrobial substances of plant origin. Cm. Antibiotics


Wednesday full — a nutrient medium containing all the necessary ingredients for. growth of auxotrophic bacteria.

Wednesday nutritious — Wednesday,

Section summary Glossary of microbiological terms with a detailed description.
Source: L. B. Borisov, I. S. Freidlin quick reference microbiological terminology. Publishing House "Medicine", Moscow, 1975

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