Nocardiaceae
Colonies of Nocardia asteroides
The Nocardiaceae constitute a family within the Actinobacteria, which inter alia contains the genera Nocardia, Rhodococcus and Smaragdicoccus. All representatives of the formerly standing in Nocardiaceae, now defunct genus Micropolyspora can now be found in the genus Nocardia.
The bacteria often occur in the soil some Rhodococcus species are found in the gut of certain insects. The genus Smaragdicoccus with the only kind Smaragdicoccus niigatensis Adachi et al. was discovered in February 2007 and assigned to the Nocardiaceae.
- 3.1 Literature
- 3.2 Notes and references
Features
The bacterial genera Nocardia and Rhodococcus need oxygen. Low levels or complete absence of oxygen they can not tolerate, which is why they are referred to as obligate aerobic. All species are immobile. On the catalase test they respond positively, they produce the enzyme catalase. Since they are not capable of photosynthesis, their diet is done chemoorganotroph by a respiratory metabolism.
Usually they form branched mycelium which often break apart in older cultures the formation of cocci and rod-shaped cells. Partial arise air spores.
Among the species are economically important species as well as some pathogens.
System
Outer systematics
The Nocardiaceae are provided along with the families Corynebacteriaceae, Dietziaceae, Mycobacteriaceae, Segniliparaceae and Tsukamurellaceae to the subordination Corynebacterineae. In other sources besides the families Williamsiaceae and Gordoniaceae be performed. Since 1999, several new species of bacteria have been discovered that were assigned to the genus Williamsia newly described in the new family Williamsiaceae. After the valid classification of bacteria, this genus, however, belongs to the family Nocardiaceae. The families Gordoniaceae and Nocardiaceae were combined into the extended family Nocardiaceae 2009.
Inside systematics
Nocardia is the type genus of the family Nocardiaceae. The Nocardiaceae following genera are found:
- Gordonia (ex Tsukamura 1971) Stackebrandt et al. 1989
- Millisia Soddell et al. 2006
- Nocardia Trevisan 1889
- Rhodococcus Zopf 1891
- Skermania Chun et al. 1997
- Smaragdicoccus Adachi et al. 2007
- Williamsia fighters et al. 1999
Some species of Nocardia asteroides with the type species of Nocardia ( Eppinger 1891) Blanchard 1896:
- Nocardia abscessus Yassin et al. 2000
- Nocardia araoensis Kageyama et al. 2004
- Nocardia brasiliensis ( Lindenberg 1909) Pinoy 1913
- Nocardia brevicatena ( Lechevalier et al., 1961) Goodfellow and Pirouz 1982
- Nocardia concava Kageyama et al. 2005
- Nocardia elegans Yassin and Brenner 2005
- Nocardia inohanensis Kageyama et al. 2004
- Nocardia paucivorans Yassin et al. 2000
- Nocardia terpenica Hoshino et al. 2007
And a selection of species of the genus Rhodococcus with the type species Rhodococcus rhodochrous ( Zopf 1891) Tsukamura 1974:
- Rhodococcus aetherivorans Goodfellow et al. 2004
- Rhodococcus baikonurensis Li et al. 2004
- Rhodococcus corynebacterioides ( Serrano et al., 1972) Yassin and Schaal 2005
- Rhodococcus percolatus Briglia et al. 1996
- Rhodococcus triatomae Yassin 2005
Some synonyms and changes
The types of Micropolyspora Lechevalier et al. 1961 were placed in the genus Nocardia. Many species of Rhodococcus were changed, eg Aichiensis Rhodococcus, Rhodococcus bronchialis, Rhodococcus chubuensis ( now Gordonia Sputi ), Rhodococcus rubropertinctus and others in the genus Gordonia. Representatives of Nocardia have been transferred to other genera. So Nocardia sulphurea is now a synonym for Amycolatopsis and Nocardia sulphurea amarae for Gordonia amarae.