Anaerobes

Anaerobes : microbes that are able to grow and multiply without access free oxygen. The toxic effects of oxygen on anaerobov, connected with suppression of activity of some bacterial enzymes. There are facultative anaerobes that can change the anaerobic respiration type on aerobic and strict (obligate) anaerobes, with only anaerobic respiration type.
At cultivation strict anaerobes used chemical solution oxygen: add in the environment surrounding anaerobov, substances, able to absorb oxygen (for example, the alkaline solution pyragollole, hydrosulfite sodium), or introduced into the nutrient media substances, capable to recover coming oxygen (for example, pyruvic acid, cysteine, glutathione and other). You can ensure the growth of anaerobic bacteria in the physical ways: mechanically remove the air from the media before sowing by boiling, followed by pouring the surface of the liquid environment vaseline oil, and use anaerostat (anaerobic jar); perform seeding prick in high column nutrient agar, filling it then viscous vaseline oil. The biological method of ensuring anoxic conditions for anaerobes is a combined, joint crops aerobes and anaerobes.
To pathogenic anaerobes are sticks tetanus, botulism, agents anaerobic infection (see Clostridia). Cm. also Bacteria.

Anaerobes - organisms that can exist and develop normally without access free oxygen.
The terms "anaerobes and anaerobic" (life without air; from the Greek. negative prefixes an-, aer - air and bios-life) proposed L. Pasteur in 1861 to characterize the conditions of existence of open microbes butyric acid fermentation. Anaerobes are capable to decompose in an oxygen-free environment organic compounds and thus to get the necessary energy for their life.
Anaerobes are widely distributed in nature: they live in the soil, sludge ponds, compost heaps, deep wounds in the gut of humans and animals - everywhere, where the decomposition of organic substances without access of air.
With respect to oxygen anaerobes share on simple (Obligate) anaerobes, which can not grow in the presence of oxygen, and conditional (optional) anaerobes that can grow and develop as in the presence of oxygen, and without it. The first group includes the majority of anaerobic bacteria of the genus Clostridium, lactic acid bacteria and butyric acid fermentation; the second group - cocci, fungi, etc. in Addition, there are microorganisms that require for their development low concentrations of oxygen - microaerophilic (Clostridium histolyticum, Clostridium tertium, some members of the genus Fusobacterium and Actinomyces).
Genus Clostridium unites about 93 species rod-shaped grampolozhitelnyh bacteria that form the terminal or subterminal disputes (printing. Fig. 1-6). To pathogenic clostridia belong to Cl. perfringens, Cl. oedema-tiens, Cl. septicum, Cl. histolyticum, Cl. sordellii, which cause anaerobic infection (gas gangrene), lung gangrene, gangrenous appendicitis, postpartum and post-abortion complications, anaerobic septicemia and food poisoning (Cl. perfringens type a, S, D, F).

anaerobes


Pathogenic anaerobes are also Cl. tetani is the causative agent of tetanus and Cl. botulinum is the causative agent of botulism.
Bacteroides genus includes 30 species of bacteria rod-shaped form, not form spores, gram-negative, most of them are strict anaerobes. Representatives of this family are found in gastrointestinal and urogenital tracts of humans and animals; some species are pathogenic, causing septicemia and abscesses.
Anaerobes kind Fusobacterium (small sticks with a thickening on the ends that do not form spores, gram), which is the inhabitants of the mouth of man and animals, in Association with other bacteria cause necrobacillosis, sore throat Vincent, gangrenous stomatitis. Anaerobic staphylococci kind Peptococcus and Streptococcus spp kind Peptostreptococcus found in healthy people in the respiratory tract, mouth, vagina, intestines. Cocci-anaerobes cause various purulent diseases: lung abscess, mastitis, cystitis, myositis, appendicitis, sepsis after childbirth and abortions, peritonitis, etc., anaerobes from the kind of Actinomyces cause actinomycosis in humans and animals.
Some anaerobes also perform useful functions: promote digestion and absorption of nutrients in the gut of humans and animals (bacteria butyric acid and lactic acid fermentation), participate in the circulation of substances in nature.
How the selection of anaerobic bacteria is based on creating anaerobic conditions (the lower partial pressure of oxygen in the environment), for which used the following methods: 1) removal of oxygen from the environment by pumping air or eviction indifferent gas; 2) chemical absorption of oxygen by means of hydrosulfite sodium or pyragollole; 3) the combined mechanical and chemical removal of oxygen; 4) biological oxygen uptake obligate aerobic microorganisms, sown on one half of the Petri dishes (method of Partner); 5) partial removal of air from a liquid nutrient medium by boiling it, add reducing substances (glucose, thioglycolate, cysteine, pieces of fresh meat or liver) and fill environment vaseline oil; 6) mechanical protection from oxygen carried out by planting anaerobes in high temperatures agar in a thin glass tubes method larvae adopted from.
Methods of identification of selected crops anaerobov - see Anaerobic infection (microbiological diagnostics).