Microaerophiles are microorganisms which are unable to grow when oxygen concentrations reach those found in air (20%) but nevertheless whose growth requires the presence of some oxygen (e.g., 2 to 10%).
Microaerophilic conditions, though not necessarily just microaerophilic microorganisms, may be found in some environments particularly at the interface between the anaerobic and the aerobic such as those found in soil, water, or part of the bodies of animals and some plants.
The answer is not microaerophile since microaerophiles require at least some oxygen to grow and therefore cannot strictly be classified as anaerobic.
The use of oxygen by an organism gives scientists a way to classify organisms based on the idea of whether the organism is an aerobe, anaerobe, microaerophile, or facultative anaerobe.
Note the methylene blue indicator strip used to tell when the air inside the chamber is oxidized (blue) or reduced (white).
In order for the best growth of microaerophiles, one must only have a small percentage of oxygen left in the container.
A Study of Peroxide Resistance in the Microaerophile, Spirillum volutans
Studies of adaptive responses of the microaerophile Spirillum volutans to various stresses such as heat and peroxide shock have been hampered by an inability to obtain reliable colony counts of the organism by the spread plate method.
Colony counts approaching direct microscopic counts (DMCs) were obtained by inoculating culture dilutions into a semisolid version of the medium and by supplementing the medium with pyruvate, which destroys hydrogen peroxide.
HELICOBACTER(Site not responding. Last check: 2007-11-02)
Infected patients can be treated with an antacid as well as tetracycline to treat the ulcers and inhibit the growth of the organism.
The microaerophilic nature of Helicobacter means that it requires a low oxygen concentration and a relatively high carbon dioxide concentration.
Sufficient colony growth can be seen in three days when the organism is plated onto Brucella-sheep blood agar and placed in a microaerophilic environment.
Microaerophile: An organism that is capable of oxygen-dependent growth but cannot grow in the presence of a level of oxygen equivalent to that present in an air atmosphere (21% oxygen).
In addition to being able to respire with oxygen, some microaerophiles may be capable of respiring anaerobically with electron acceptors other than oxygen.
(Note that microaerophiles are not included.) The accompanying table gives related information.
Expression of the peroxide stress genes alkyl hydroperoxide reductase (ahpC) and catalase (katA) of the microaerophile Campylobacter
Campylobacter jejuni is a gram-negative, microaerophilic enteric pathogen of humans, causing gastroenteritis.
An iron-regulated alkyl hydroperoxide reductase confers aerotolerance and oxidative stress resistance to the microaerophilic pathogen Campylobacter jejuni.
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A microaerophile: a) grows best in an anaerobic jar b) grows with or without oxygen c) needs normal atmospheric levels of oxygen d) requires a small amount of oxygen but won't grow at normal atmospheric levels e) none of the choices are correct
Superoxide reductase as a unique defense system against superoxide stress in the microaerophile Treponema pallidum -- Lombard et al., 10.1074/jbc.M004201200 -- Journal of Biological Chemistry
Superoxide reductase as a unique defense system against superoxide stress in the microaerophile Treponema pallidum
Treponema pallidum, a microaerophilic bacterium responsible for venereal syphilis, is an interesting organism because it lacks all the above-mentioned enzymes, as deduced from an analysis of its recently sequenced genome.
