''Alcaligenes faecalis'' is a species of
Gram-negative
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...
, rod-shaped bacteria commonly found in the environment. It was originally named for its first discovery in
feces
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a rela ...
, but was later found to be common in soil, water, and environments in association with humans. While
opportunistic infection
An opportunistic infection is an infection caused by pathogens (bacteria, fungi, parasites or viruses) that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immun ...
s do occur, the
bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...
is generally considered nonpathogenic. When an opportunistic infection does occur, it is usually observed in the form of a urinary tract infection.
''A. faecalis'' has been used for the production of
nonstandard amino acids.
Description
''A. faecalis'' is a Gram-negative bacterium which appears
rod-shaped
A bacillus (), also called a bacilliform bacterium or often just a rod (when the context makes the sense clear), is a rod-shaped bacterium or archaeon. Bacilli are found in many different taxonomic groups of bacteria. However, the name '' Baci ...
and motile under a microscope. It is positive by the
oxidase test and
catalase test, but negative by the
nitrate reductase test
The nitrate reductase test is a test to differentiate between bacteria based on their ability or inability to reduce nitrate (NO3−) to nitrite (NO2−) using anaerobic respiration.
Procedure
Various assays for detecting nitrate reduction have ...
. It is
alpha-hemolytic
Hemolysis (from Greek αιμόλυση, meaning 'blood breakdown') is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly ...
and
requires oxygen. ''A. faecalis'' can be grown at 37 °C, and forms colonies that lack pigmentation.
Metabolism
The bacterium degrades
urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid.
Urea serves an important ...
, creating ammonia which increases the pH of the environment. Although ''A. faecalis'' is considered to be alkali-tolerant, it maintains a neutral pH in its cytosol to prevent the damaging or denaturing of its charged species and macromolecules.
[
]
History
''A. faecalis'' may have been isolated by Johannes Petruschky in 1896, and also described (and they state, the description corrected) in 1919 by Castellani and Chalmers.[ ''A. faecalis phenolicus'' is distinguished by its ability to use ]phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it r ...
as a carbon source.[
]
References
External links
Type strain of ''Alcaligenes faecalis'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
Burkholderiales
Bacteria described in 1919
{{Betaproteobacteria-stub