Nocardiaceae
Encyclopedia
The Nocardiaceae are a family of aerobic
, non-fastidious, high G+C
, Gram-positive
actinomycetes that are commonly found in soil and water. Members of this family have been isolated from Antarctic
soils. Nocardiaceae present coccobacilli, filamentous or, rarely, fragmented and palisading forms, and filamentous species grow in a branching morphological pattern similar to fungal hyphae.
and Rhodococcus
genera can cause infection in humans and livestock. Many members of this family integrate mycolic acids into their cell wall
, and as a result, Nocardia spp. may be mistaken for mycobacteria when viewed under a microscope following an acid-fast stain.
during wastewater treatment
. Biological foaming can be problematic for the water treatment process, and foam accumulation is reduced by adding surfactants to the wastewater.
distillates) and have been proposed as bioremediation agents for environmental spills.
genus were transferred to the genera Nocardia
, Nonomuraea in family Streptosporangiaceae, or Saccharopolyspora
in family Pseudonocardiaceae
. This effectively ended the official status of this genus, but the name persists in older research articles.
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
, non-fastidious, high G+C
High-GC content bacteria
High-GC content bacteria are Gram-positive bacteria with a high number of guanine and cytosine bases as compared to adenine and thymine. These bacteria are of the class Actinobacteria . For more information, see GC-content....
, Gram-positive
Gram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
actinomycetes that are commonly found in soil and water. Members of this family have been isolated from Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
soils. Nocardiaceae present coccobacilli, filamentous or, rarely, fragmented and palisading forms, and filamentous species grow in a branching morphological pattern similar to fungal hyphae.
Pathogenic capacity
Some species colonize animals, and members of the NocardiaNocardia
Nocardia is a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. It forms partially acid-fast beaded branching filaments . It has a total of 85 species. Some species are non-pathogenic while others are responsible for nocardiosis. Nocardia are found worldwide in soil...
and Rhodococcus
Rhodococcus
Rhodococcus is a genus of aerobic, nonsporulating, nonmotile Gram-positive bacteria closely related to Mycobacteria and Corynebacteria. While a few species are pathogenic, most are benign and have been found to thrive in a broad range of environments, including soil, water, and eukaryotic cells...
genera can cause infection in humans and livestock. Many members of this family integrate mycolic acids into their cell wall
Cell wall
The cell wall is the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. It is located outside the cell membrane and provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to...
, and as a result, Nocardia spp. may be mistaken for mycobacteria when viewed under a microscope following an acid-fast stain.
Wastewater foaming
Nocardia species are often responsible for the accumulation of foam that occurs in activated sludgeActivated sludge
Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoans.-Purpose:...
during wastewater treatment
Wastewater Treatment
Wastewater treatment may refer to:* Sewage treatment* Industrial wastewater treatment...
. Biological foaming can be problematic for the water treatment process, and foam accumulation is reduced by adding surfactants to the wastewater.
Bioremediation of hydrocarbons
Soil Nocardiaceae can degrade hydrocarbons (e.g. petroleumPetroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
distillates) and have been proposed as bioremediation agents for environmental spills.
Nomenclature changes
In the 1980s, all Nocardiaceae species assigned to the MicropolysporaMicropolyspora
Micropolyspora is a now defunct genus of bacteria from family Nocardiaceae. Members of this genus were transferred to new genera in families Nocardiaceae, Streptosporangiaceae and Pseudonocardiaceae...
genus were transferred to the genera Nocardia
Nocardia
Nocardia is a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. It forms partially acid-fast beaded branching filaments . It has a total of 85 species. Some species are non-pathogenic while others are responsible for nocardiosis. Nocardia are found worldwide in soil...
, Nonomuraea in family Streptosporangiaceae, or Saccharopolyspora
Saccharopolyspora
Saccharopolyspora is a genus of bacteria within the family Pseudonocardiaceae....
in family Pseudonocardiaceae
Pseudonocardiaceae
Pseudonocardiaceae is a family of bacteria in the order Actinomycetales.-Genera:* Type genus: Pseudonocardia, Henssen 1957 * Actinoalloteichus* Actinobispora* Actinomycetospora* Allokutzneria* Amycolata...
. This effectively ended the official status of this genus, but the name persists in older research articles.