title: Filamentous growth in activated sludge.
abstract: Bulking and foaming in activated sludge have been associated with filamentous overgrowth. Filamentous Nocardia amarae and nonfilamentous Pseudomonas auruginosa were cultured using fatty acids (C2-C24) as the sole carbon. N. amarae could utilize all acids tested for growth, whereas P. auruginosa hardly grew on acids with 12 or more carbons. Maximum specific growth rate and saturation constant of N. amarae on C24, at 0.048 h-1 and 1.520 g COD/L, respectively, were much lower than that of P. auruginosa, showing that N. amarae had a relatively stronger affinity for long-chain fatty acids. N. amarae was competitive in activated sludge processes that receive sewage containing a high proportion of long-chain fatty acids, oils, and fats.
authors.affiliation: Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: H
authors.initials: H
authors.lastname: Chua
authors.forename: K N
authors.initials: KN
authors.lastname: Tan
authors.forename: M W
authors.initials: MW
authors.lastname: Cheung
mesh_terms: D002244:Carbon; D005227:Fatty Acids / Q000494:pharmacology*; D007218:Industrial Microbiology; D007700:Kinetics; D009615:Nocardia / Q000187:drug effects / Q000254:growth & development*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development*; D012722:Sewage / Q000382:microbiology*
chemical_list: D005227:Fatty Acids; D012722:Sewage; D002244:Carbon