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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 ...
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 ...
It is ideally spatially unstructured and temporally unstructured, in a steady state defined by the rates of nutrient supply and bacterial growth. In comparison to batch culture, bacteria are maintained in exponential growth phase, and the growth rate of the bacteria is known. Related devices include turbidostats and auxostats.
Bacterial morphological plasticity refers to changes in the shape and size that bacterial cells undergo when they encounter stressful environments. Although bacteria have evolved complex molecular strategies to maintain their shape, many are able to alter their shape as a survival strategy in response to protist predators, antibiotics, the immune response, and other threats.
A graph of this equation creates an S-shaped curve, which demonstrates how initial population growth is exponential due to the abundance of resources and lack of competition. When factors that limit an organisms growth are not available in constant supply to meet the growing demand, such as RNA and protein amounts in bacteria, the growth of the ...
Likewise, there are many lithotrophic bacteria that also convert ammonium into nitrogen gas in a process called denitrification. [27] Carbon and nitrogen are important nutrients, essential for metabolic processes, and can sometimes be the limiting factor that affects organismal growth and development.
Evidence of possibly the oldest forms of life on Earth has been found in hydrothermal vent precipitates. [1]The earliest known life forms on Earth may be as old as 4.1 billion years (or Ga) according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. [2]
Horizontal gene transfer is the primary mechanism for the spread of antibiotic resistance in bacteria, [8] [5] [9] [10] and plays an important role in the evolution of bacteria that can degrade novel compounds such as human-created pesticides [11] and in the evolution, maintenance, and transmission of virulence. [12]