Microbial Associations

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Microbial Associations


natural or man-made communities of microorganisms, such as bacteria, yeasts, algae, and fungi.

Microbial associations develop through symbiosis or metabiosis. Certain species of microorganisms that constitute an association are not only usually resistant to the products of the vital activities of the other species in the association but in fact use those products as sources of energy, carbon, nitrogen, or growth factor.

Some microbial associations are evolutionarily ancient and very stable. One example is lichens, which consist of photosynthesizing algae and heterotrophic fungi. The mucilage canals of birch and oak are inhabited by yeasts that ferment sugar to ethyl alcohol. The alcohol is oxidized by acetic-acid bacteria to acetic acid, which can then be oxidized by fungi and bacteria to carbon dioxide and water. Microbial associations of anaerobes and aerobes are also formed in the soil. The aerobes use up the oxygen and thereby make possible the development of the anaerobes. Cellobiose and glucose, which form upon the destruction of plant remains by cellulose-decomposing bacteria, are metabolized by nitrogen-fixing bacteria; these, after decomposing, serve as a source of nitrogen nutrition for the cellulose bacteria. A common association is one of yeasts and lactic-acid bacteria, the yeasts being resistant to lactic acid and the bacteria to ethyl alcohol. The type includes the ferments used for kefir and rye dough.

A unique microbial association is the mucoid “tea fungus,” which consists of yeasts and acetic-acid bacteria, and is used in the home to produce a sour beverage. A stable, artificially created microbial association is the commercial “M” race of yeasts Saccharomyces cerevisiae, which consists of three different strains.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Taxa-Based Microbial Associations with Disease States
Analysis of the microbiota in humans and in animal disease models has permitted the identification of specific taxa-based microbial associations with disease states.
Herewith, 7.1% of the cases were with combination of Mycoplasma and Trichomonas infections, 9.5% of cases showed microbial associations of chlamydia and gardnerella.
Among the variety of microbial agents persisting in the endometrium of women of the study group, dominant role belongs to the mycoplasma infection (33.2%) and microbial associations (78.6%).
Hereby, we conducted a comprehensive study of the endometrium (hysteroscopic, morphological, and immunological research on genital infection) of patients with reproductive disorders and revealed a high frequency (73.8%) of hyperplastic processes of endometrium (endometrial hyperplasia, polyps), and in the most cases (73.8%), infection of the endometrium with a predominance of microbial associations (78.6%) and mycoplasma infections (33.2%).
The number of the allocated microbial associations depending on the patients' length of stay in a hospital is shown in Table 3.
Frequency and structure of the met microbial associations allocated from patients is presented in Table 4.
Ideally the host would be optically transparent, small enough for its entire digestive tract to be visualized, and amenable to microbiological manipulations, such as the ability to generate gnotobiotic animals with defined microbial associations. The zebrafish larva offers all of these features, as well as a rich research history that has generated many valuable protocols and reagents for experimental manipulations.