Photochromogen | definition of photochromogen by Medical dictionary
a microorganism whose pigmentation develops as a result of exposure to light. adj., adj photochromogen´ic.
1 a pigment that develops as a result of exposure to light.
2 a type of mycobacterium that is nonpigmented in the dark but produces a yellow pigment on constant exposure to light.
photochromogen (fō-tō-krō′mō-jĕn) [″ + chroma, color, + gennan, to produce]
Certain microorganisms in which a pigment develops when it is grown in the presence of light, such as Mycobacterium kansasii.
a microorganism whose pigmentation develops as a result of exposure to light. A characteristic of Runyon Group I mycobacteria.
References in periodicals archive
Define rapid grower, scotochromogen, photochromogen
, and nonchromogen and provide examples of mycobacteria in each category.
Mycobacterium marinum is a photochromogen
classified as a Mycobacterium organism other than Mycobacterium tuberculosis (MOTT), and is known to cause human skin infection.
Nontuberculous mycobacteria are also called as atypical mycobacteria and are classified into: 1) Photochromogens
2) Scotochromogen 3) Nonchromogens 4) Rapid growers.
(Group I): Produce non-pigmented colonies in dark and pigmented colonies when exposed to light and re-incubation e.