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However, gene sequences can be used to reconstruct the bacterial phylogeny, and these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. [15] The most recent common ancestor (MRCA) of bacteria and archaea was probably a hyperthermophile that lived about 2.5 billion–3.2 billion years ago.
Eubacterium is a genus of Gram-positive bacteria in the family Eubacteriaceae.These bacteria are characterised by a rigid cell wall.They may either be motile or nonmotile. If motile, they have a flagellu
As microorganisms, in particular bacteria, are found virtually everywhere, harmful microorganisms may be reduced to acceptable levels rather than actually eliminated. In food preparation, microorganisms are reduced by preservation methods such as cooking, cleanliness of utensils, short storage periods, or by low temperatures.
Pathogenic bacteria are bacteria that can cause disease. [1] This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and many are beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. [2]
These harmful algal blooms are more likely to be produced at a dangerous amount when there is an excess of nutrients, the temperature is 20 °C, there is more light, and calmer waters. [17] Eutrophication and other contamination can lead to an environment that promotes cyanobacteria blooms. [17]
Thermophiles can survive at high temperatures, whereas other bacteria or archaea would be damaged and sometimes killed if exposed to the same temperatures. The enzymes in thermophiles function at high temperatures. Some of these enzymes are used in molecular biology, for example the Taq polymerase used in PCR. [4] "
Anaerobic bacteria can be divided into strict anaerobes that can not grow in the presence of more than 0.5% oxygen and moderate anaerobic bacteria that are able of growing between 2 and 8% oxygen. [1] Anaerobic bacteria usually do not possess catalase, but some can generate superoxide dismutase which protects them from oxygen.
[7] [12] The diderm bacteria can also be further differentiated between simple diderms lacking lipopolysaccharide (LPS); the archetypical diderm bacteria, in which the outer cell membrane contains lipopolysaccharide; and the diderm bacteria in which the outer cell membrane is made up of mycolic acid (e. g. Mycobacterium). [9] [10] [12] [13]