title: Foam-forming bacteria in activated sludge effectively reduced by rotifers in laboratory- and real-scale wastewater treatment plant experiments.
abstract: Lecane inermis rotifers were shown to diminish sludge bulking due to their ability to ingest the filamentous bacteria in activated sludge. To determine if rotifers are also able to control branched actinomycetes, we investigated three other Lecane species (Monogononta). In a week-long experiment, only Lecane tenuiseta significantly reduced the density of Microthrix parvicella and Type 0092 filaments, but in a 2-week experiment, actinomycetes were significantly reduced by most of the tested monogonont rotifers: L. inermis, Lecane decipiens and Lecane pyriformis. Rotifers L. inermis originating from the mass culture were artificially introduced into real-scale wastewater treatment plant (WWTP) in two series. The WWTP was monitored for 1 year. Rotifer inoculation resulted in diminishing of M. parvicella and actinomycete abundance. The experiments showed that different species of rotifers vary in their effectiveness at limiting various types of filamentous organisms. This is the first report demonstrating that one of the most troublesome bacteria, branched actinomycetes, which cause heavy foaming in bioreactors, can be controlled by rotifers. Knowledge of the consumers of filamentous bacteria that inhabit activated sludge could help WWTP operators overcome bulking and foaming through environmentally friendly methods.
authors.affiliation: Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland. agnieszka.pajdak-stos@uj.edu.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Pajdak-Stós
authors.affiliation: Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
authors.forename: Wioleta
authors.initials: W
authors.lastname: Kocerba-Soroka
authors.affiliation: Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Fyda
authors.affiliation: Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Sobczyk
authors.affiliation: Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Fiałkowska
mesh_terms: D000818:Animals; D001419:Bacteria; D019149:Bioreactors; D012403:Rotifera; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid; D062065:Wastewater
chemical_list: D012722:Sewage; D062065:Wastewater
keywords: Actinomycetes; Filamentous bacteria; Lecane rotifers; Sludge bulking; Wastewater treatment plant