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A mode of life carried on in the absence of molecular oxygen.



(also anoxybiosis), life in the absence of free oxygen. Anaerobiosis is the usual condition of existence for the anaerobic organisms which obtain energy for vital activities from the decomposition of compound inorganic substances (for example, nitrates and sulfates) or organic substances (for example, carbohydrates).

The concept of anaerobiosis was introduced in 1861 by L. Pasteur, who showed that the microorganisms that cause lactic acid fermentation die in the presence of oxygen. In multicelled animals, anaerobiosis is often only a temporary state which provides for survival during periods when there is no oxygen, and it is accompanied by a sharp decline in metabolism and a transformation to an inactive state. Aerobic organisms also have anaerobic stages in the metabolic processes that are accompanied by the generation of energy. In the tissues of a majority of the multicelled animals, anaerobic carbohydrate conversion occurs chiefly by glycolysis. In rapidly growing embryonic cells and in tumor cells, anaerobic processes are more strongly expressed than in the normal cells of a healthy organism. The processes of anaerobic conversion (fermentation and putrefaction) are of great significance in the circulation of matter in nature.

References in periodicals archive ?
It also provides good yield of growth as inoculation and anaerobiosis is initiated at collection point.
1 w/v) y cultivos diluidos a 1 ml, con shock termico preliminar a 90[degrees]C por 5 minutos, en placas de Petri con agar SPS con el metodo de profundidad; e incubados a 35 [+ or -] 2[degrees]C por 72 horas en anaerobiosis.
2006), se incubaron en condiciones de anaerobiosis durante 7 dias con el fin de obtener 3,5 g de la bacteria.
El grado de anaerobiosis es proporcional a la profundidad y severidad del choque hemorragico, el cual se refleja en el deficit de bases y el nivel de lactato.
Soils and litter were incubated for 24 h in anaerobiosis to ensure total transformation of the nitrate into [N.
roots, that although rapid biochemical changes were induced by anaerobiosis, these changes were temporary.
Anaerobiosis and symbiosis with bacteria in free-living ciliates.
Estos aislados fueron luego sembrados en agar yema de huevo e incubadas a 37[grados]C durante 18-24 h bajo anaerobiosis para evidenciar la reaccion de Nagler.
Por su parte, los estreses que conducen a un incremento en el titulo de putrescina incluyen deficiencia de K+, nutricion por amonio, exposicion a pH bajos, estres osmotico, toxicidad por Cd y SOz, anaerobiosis, radiacion UV B (Galston y Sawhney, 1990; Flores, 1991), tratamiento con atrazina (Zheleva et al.
La proporcion de cepas bacterianas capaces de crecer en tioglicolato fue similar (33%) entre los distintos compartimientos, indistintamente de las condiciones de anaerobiosis.