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The microbes resembled modern hydrothermal vent bacteria, supporting the view that abiogenesis began in such an environment. [78] However, later research disputed this interpretation of the data, stating that the observations may be better explained by abiotic processes in silica-rich waters, [ 79 ] "chemical gardens," [ 80 ] circulating ...
The autotrophic nature of anammox bacteria and ammonia-oxidizing bacteria guarantee a low yield and thus less sludge production. [69] Additionally, anammox bacteria easily form stable self-aggregated biofilm (granules) allowing reliable operation of compact systems characterized by high biomass concentration and conversion rate up to 5–10 kg ...
A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world. Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come into existence. These include ...
Conjugation: Bacteria directly transfer genes from one cell to another; Transduction: Bacteriophages (virus) move genes from one bacterial cell to another; Once one of these mechanisms has occurred the bacteria will continue to multiply and grow resistance and evolve by natural selection.
[5] [6] Two examples of obligate anaerobes are Clostridium botulinum and the bacteria which live near hydrothermal vents on the deep-sea ocean floor. Aerotolerant organisms, which cannot use oxygen for growth, but tolerate its presence. [7] Facultative anaerobes, which can grow without oxygen but use oxygen if it is present. [7]
Purple and green bacteria oxidize sulfide, sulfur, sulfite, iron or hydrogen. Cyanobacteria and plants extract reducing equivalents from water, i.e., they oxidize water to oxygen. The electrons obtained from the electron donors are not used for ATP production (as long as there is light); they are used in biosynthetic reactions.
Dissolved oxygen increases the redox potential of a solution, and high redox potential inhibits the growth of some obligate anaerobes. [ 3 ] [ 5 ] [ 7 ] For example, methanogens grow at a redox potential lower than -0.3 V. [ 7 ] Sulfide is an essential component of some enzymes, and molecular oxygen oxidizes this to form disulfide , thus ...
Despite the bactericidal effects of ethanol, acidifying effects of fermentation, and low oxygen conditions of industrial alcohol production, bacteria that undergo lactic acid fermentation can contaminate such facilities because lactic acid has a low pKa of 3.86 to avoid decoupling the pH membrane gradient that supports regulated transport.