Nocardiaceae

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Nocardiaceae
Rhodococcus
Rhodococcus
Scientific classification
Kingdom: Bacteria
Division: Actinobacteria
Class: Actinobacteria
Subclass: Actinobacteridae
Order: Actinomycetales
Suborder: Corynebacterineae
Family: Nocardiaceae
Garrity et al. 2001
Genera

Nocardia
Rhodococcus
Smaragdicoccus
Micropolyspora (now defunct)

The Nocardiaceae are a family of aerobic, non-fastidious, high G+C, Gram-positive actinomycetes that are commonly found in soil and water.[1] Some bacteria from this family are even indigenous to the Antarctic.[2] Nocardiaceae present coccobacilli, filamentous or, rarely, fragmented and palisading forms,[3] and filamentous species grow in a branching morphological pattern similar to fungal hyphae.[4]

Contents

[edit] Pathogenic capacity

Some species colonize animals, and members of the Nocardia and Rhodococcus genera can cause infection in humans and livestock.[5] 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.[6]

[edit] Environmental effects

[edit] Wastewater foaming

Nocardia species are often responsible for the accumulation of foam that occurs in activate sludge during wastewater treatment.[4][7][8][9] Biological foaming can be problematic for the water treatment process, and foam accumulation is reduced by adding surfactants to the wastewater.[10][11]

[edit] Bioremediation of hydrocarbons

Soil Nocardiaceae can degrade hydrocarbons (e.g. petroleum distillates) and have been proposed as bioremediation agents for environmental spills.[12]

[edit] Nomenclature changes

In the 1980's, all Micropolyspora spp. were transferred to the genera Nocardia, Nonomuraea in family Streptosporangiaceae, or Saccharopolyspora in family Pseudonocardiaceae.[13] This effectively ended the official status of this genus, but the name persists in older research articles.

[edit] References

  1. ^ Stackebrandt, E., Rainey, F.A. and N.L. Ward-Rainey. 1997. Proposal for a new hierarchic classification system, Actinobacteria classis nov. Int. J. Syst. Bacteriol., 1997, 47:479-491.
  2. ^ Aislabie, J. Ecosystems Processes in Antarctic Ice-Free Landscapes. "Hydrocarbon-degrading bacteria in oil-contaminated soils near Scott Base, Antarctica." Page 257.
  3. ^ Kulich, S.M. and W.A. Pasculle. Final Diagnosis - Pneumonia, Hilar Lymphadenitis and Sepsis Secondary to Rhodococcus equi. The University of Pittsburgh School of Medicine. Retrieved October 20, 2007.
  4. ^ a b Bitton, G. Wastewater Microbiology. "Foam Microbiology." page 229.
  5. ^ Castellani, A. and A.J. Chalmers. 1919. Manual of Tropical Medicine, 3rd ed., Williams Wood and Co., New York, p. 1040.
  6. ^ Nocardia: a serious matter for cows. Presentation images from: aids-images.ch. Retrieved October 20, 2007.
  7. ^ Blackall, L.L., Tandoi, V., Jenkins, D. 1991. Continuous culture studies with Nocardia amarae from activated sludge and their implications for Nocardia foaming control. Res. J. Water Pollution Cont. Fed. 63:44-50.
  8. ^ Pitt, P., and D. Jenkins. 1990. Causes and Control of Nocardia in Activated Sludge. Res. J. Water Pollution Cont. Fed. 62:143-150.
  9. ^ Blackall, L.L. 1994. Microorganisms in activated sludge and biofilm processes. Water Sci. Technol. 29:35-44.
  10. ^ Shao, Y.J., Starr, M., Kaporis, K., Kim, H.S., Jenkins, D. 1997. Polymer addition as a solution to Nocardia foaming problems. Water Enviro. Res., 69:25-27.
  11. ^ Ho, C.F., Jenkins, D. 1991 Effect of surfactants on Nocardia foaming in activated sludge. Water Sci. Tech. 23:879-887.
  12. ^ Aislabie, J., McLeod, M., and R. Fraser. Potential for biodegradation of hydrocarbons in soil from the Ross Dependency, Antarctica. Appl. Microbiol. Biotechnol. 49:210-214.
  13. ^ Euzéby. J.P. List of Prokaryotic names with Standing in Nomenclature - Genus Micropolyspora. From: www.bacterio.cict.fr. Retrieved October 20, 2007