title: Characterization of Nocardia farcinica, a filamentous bacterium isolated from foaming activated sludge samples.
abstract: The identification and characterization of filamentous bacteria and their association with specific plant operating conditions and influent characteristics has been hampered because of morphological variations and differences between process configurations. A study was conducted to isolate and characterize the predominant filamentous bacteria observed in a foaming activated sludge treatment plant. The predominant foam-forming filament was isolated and characterized using microscopic, biochemical and molecular techniques. The phylogenetic analysis of the 16S rRNA gene confirmed that it was Nocardia farcinica, a typical filamentous foam-foaming pathogenic bacterium which is not widely reported outside of South Africa. The bacterium used a variety of substrates for its growth and showed greater affinity to larger and slowly biodegradable compounds. The N. farcinica grew well at temperatures ranging from 12 to 30 degrees C in R2A medium and with a pH ranging from 5.5 to 8.0 and an NaCl concentration of 1 to 5%. This range of conditions shows that N. farcinica can withstand extreme conditions, which results in its proliferation in foaming samples.
authors.affiliation: Institute for Water and Wastewater Technology, Department of Biotechnology and Food Technology, Faculty of Applied Sciences, Durban University of Technology, Durban, South Africa.
authors.forename: Dashika
authors.initials: D
authors.lastname: Naidoo
authors.forename: Sheena
authors.initials: S
authors.lastname: Kumari
authors.forename: Faizal
authors.initials: F
authors.lastname: Bux
mesh_terms: D006863:Hydrogen-Ion Concentration; D009615:Nocardia / Q000145:classification* / Q000166:cytology / Q000235:genetics* / Q000502:physiology; D010802:Phylogeny; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D014865:Waste Disposal, Fluid; D014871:Water Microbiology
chemical_list: D012722:Sewage