title: Occurrence of Legionella in wastewater treatment plants linked to wastewater characteristics.
abstract: In recent years, the occurrence of Legionella in wastewater treatment plants (WWTP) has often been reported. However, until now there is limited knowledge about the factors that promote Legionella's growth in such systems. The aim of this study was to investigate the chemical wastewater parameters that might be correlated to the concentration of Legionella spp. in WWTP receiving industrial effluents. For this purpose, samples were collected at different processes in three WWTP. In 100 % of the samples taken from the activated sludge tanks Legionella spp. were detected at varying concentrations (4.8 to 5.6 log GU/mL) by the quantitative real-time polymerase chain reaction method, but not by the culture method. Statistical analysis with various parameters yielded positive correlations of Legionella spp. concentration with particulate chemical oxygen demand, Kjeldahl nitrogen and protein concentration. Amino acids were quantified in wastewater and activated sludge samples at concentrations that may not support the growth of Legionella, suggesting that in activated sludge tanks this bacterium multiplied in protozoan hosts.
authors.affiliation: Institute for Sanitary Engineering and Waste Management, Leibniz University Hannover, Welfengarten 1, Hannover, 30167, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Caicedo
authors.affiliation: Institute of Technical Chemistry, Leibniz University Hannover, Hannover, 30167, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Beutel
authors.affiliation: Institute of Technical Chemistry, Leibniz University Hannover, Hannover, 30167, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Scheper
authors.affiliation: Institute for Sanitary Engineering and Waste Management, Leibniz University Hannover, Welfengarten 1, Hannover, 30167, Germany.
authors.forename: K H
authors.initials: KH
authors.lastname: Rosenwinkel
authors.affiliation: Institute for Sanitary Engineering and Waste Management, Leibniz University Hannover, Welfengarten 1, Hannover, 30167, Germany. nogueira@isah.uni-hannover.
authors.forename: R
authors.initials: R
authors.lastname: Nogueira
mesh_terms: D004784:Environmental Monitoring; D007875:Legionella / Q000254:growth & development*; D060888:Real-Time Polymerase Chain Reaction; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods / Q000706:statistics & numerical data*; D062065:Wastewater / Q000382:microbiology*
chemical_list: D012722:Sewage; D062065:Wastewater
keywords: Activated sludge tanks; Amino acids; Industrial effluents; Legionella spp.; Proteins; Wastewater treatment plants