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Acetic acid is equally a co-metabolite of the organic substrates fermentation (sugars, glycerol, lactic acid, etc.) by diverse groups of microorganisms which produce different acids: Propionic bacteria (propionate + acetate); Clostridium (butyrate + acetate); Enterobacteria (acetate + lactate); and
Anaerobic digestion occurs naturally in some soils and in lake and oceanic basin sediments, where it is usually referred to as "anaerobic activity". [ 2 ] [ 3 ] This is the source of marsh gas methane as discovered by Alessandro Volta in 1776.
The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation. [2] The water cycle involves the exchange of energy, which leads to temperature changes. When water evaporates, it takes up energy from its surroundings and cools the environment. When it condenses, it releases energy and warms the environment.
This is done independent of oxygen and is thus anaerobic. Like in standard fermentation pathways, propionate fermentation involves the bacterium taking up saccharides, such as glucose, and breaking them down through glycolysis to produce pyruvate. Pyruvate is then converted into propionic acid through multiple reduction steps in the Wood ...
A biogeochemical cycle, or more generally a cycle of matter, [1] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...
The Crabtree effect, named after the English biochemist Herbert Grace Crabtree, [1] describes the phenomenon whereby the yeast, Saccharomyces cerevisiae, produces ethanol (alcohol) in aerobic conditions at high external glucose concentrations rather than producing biomass via the tricarboxylic acid (TCA) cycle, the usual process occurring aerobically in most yeasts e.g. Kluyveromyces spp. [2 ...
Following the Greeks, the idea of a hydrological cycle (water is considered a nutrient) was validated and quantified by Halley in 1687. Dumas and Boussingault (1844) provided a key paper that is recognized by some to be the true beginning of biogeochemistry, where they talked about the cycle of organic life in great detail.
The terms aerobic respiration, anaerobic respiration and fermentation (substrate-level phosphorylation) do not refer to primary nutritional groups, but simply reflect the different use of possible electron acceptors in particular organisms, such as O 2 in aerobic respiration, or nitrate (NO − 3), sulfate (SO 2−