Nocardiaceae | |
---|---|
Nocardia asteroides colonies | |
Scientific classification | |
Domain: | Bacteria |
Phylum: | Actinomycetota |
Class: | Actinomycetia |
Order: | Mycobacteriales |
Family: |
Nocardiaceae Castellani and Chalmers 1919 (Approved Lists 1980) [1] |
Type genus | |
Nocardia Trevisan 1889 (Approved Lists 1980)
| |
Genera [2] | |
| |
Synonyms | |
|
The Nocardiaceae are a family of aerobic, non-fastidious, high G+C, Gram-positive actinomycetes that are commonly found in soil and water. [3] Members of this family have been isolated from Antarctic soils. [4] Nocardiaceae present coccobacilli, filamentous or, rarely, fragmented and palisading forms, [5] and filamentous species grow in a branching morphological pattern similar to fungal hyphae. [6]
The Nocardiaceae form a monophyletic clade within the Corynebacteriales in both 16S rRNA and protein-based phylogenetic trees. [7] [8] A number of conserved signature indels and conserved signature proteins have been identified which are uniquely found in the genera Nocardia and Rhodococcus, supporting a close relationship between the two genera. [8] Recent proposals have been made, based on 16S rRNA signature nucleotides and chemotaxonomic markers, to add the genera Gordonia, Skermania, Williamsia, Millisia, and Smaragdicoccus to the family Nocardiaceae. [7] [9] However, no conserved signature indels or proteins have been found that are commonly shared by Nocardia, Rhodococcus, and Gordonia, the fully sequenced members of the proposed Nocardiaceae revision. [8]
Some species colonize animals, and members of the Nocardia and Rhodococcus genera can cause infection in humans and livestock. [10] Nocardiosis represent also a serious health problem for fish (marine or not). [11] 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. [12]
Nocardia species are often responsible for the accumulation of foam that occurs in activated sludge during sewage treatment. [6] [13] [14] [15] Biological foaming can be problematic for the water treatment process, and foam accumulation is reduced by adding surfactants to the wastewater. [16] [17]
Soil Nocardiaceae can degrade hydrocarbons (e.g. petroleum distillates) and have been proposed as bioremediation agents for environmental spills. [18]
In the 1980s, all Nocardiaceae species assigned to the genus Micropolyspora were transferred to the genera Nocardia or Nonomuraea in family Streptosporangiaceae, or Saccharopolyspora in family Pseudonocardiaceae. [19] This effectively ended the official status of this genus, but the name persists in older research articles.
Nocardiaceae | |
---|---|
Nocardia asteroides colonies | |
Scientific classification | |
Domain: | Bacteria |
Phylum: | Actinomycetota |
Class: | Actinomycetia |
Order: | Mycobacteriales |
Family: |
Nocardiaceae Castellani and Chalmers 1919 (Approved Lists 1980) [1] |
Type genus | |
Nocardia Trevisan 1889 (Approved Lists 1980)
| |
Genera [2] | |
| |
Synonyms | |
|
The Nocardiaceae are a family of aerobic, non-fastidious, high G+C, Gram-positive actinomycetes that are commonly found in soil and water. [3] Members of this family have been isolated from Antarctic soils. [4] Nocardiaceae present coccobacilli, filamentous or, rarely, fragmented and palisading forms, [5] and filamentous species grow in a branching morphological pattern similar to fungal hyphae. [6]
The Nocardiaceae form a monophyletic clade within the Corynebacteriales in both 16S rRNA and protein-based phylogenetic trees. [7] [8] A number of conserved signature indels and conserved signature proteins have been identified which are uniquely found in the genera Nocardia and Rhodococcus, supporting a close relationship between the two genera. [8] Recent proposals have been made, based on 16S rRNA signature nucleotides and chemotaxonomic markers, to add the genera Gordonia, Skermania, Williamsia, Millisia, and Smaragdicoccus to the family Nocardiaceae. [7] [9] However, no conserved signature indels or proteins have been found that are commonly shared by Nocardia, Rhodococcus, and Gordonia, the fully sequenced members of the proposed Nocardiaceae revision. [8]
Some species colonize animals, and members of the Nocardia and Rhodococcus genera can cause infection in humans and livestock. [10] Nocardiosis represent also a serious health problem for fish (marine or not). [11] 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. [12]
Nocardia species are often responsible for the accumulation of foam that occurs in activated sludge during sewage treatment. [6] [13] [14] [15] Biological foaming can be problematic for the water treatment process, and foam accumulation is reduced by adding surfactants to the wastewater. [16] [17]
Soil Nocardiaceae can degrade hydrocarbons (e.g. petroleum distillates) and have been proposed as bioremediation agents for environmental spills. [18]
In the 1980s, all Nocardiaceae species assigned to the genus Micropolyspora were transferred to the genera Nocardia or Nonomuraea in family Streptosporangiaceae, or Saccharopolyspora in family Pseudonocardiaceae. [19] This effectively ended the official status of this genus, but the name persists in older research articles.