title: Modelling seasonal dynamics of "Microthrix parvicella".
abstract: The filamentous bacteria "Microthrix parvicella" can cause serious bulking and scumming in wastewater treatment plants (WWTPs) all over the world. Decades of research have identified Microthrix as a specialized lipid consumer but could not clarify the processes that allow this organism to successfully compete in activated sludge systems. In this study we developed a model, based on ASM3, that describes the pronounced seasonal variations of Microthrix abundance observed in a full-scale WWTP. We hypothesize that low temperatures reduce the solubility of lipids and inhibit their uptake by non-specialized bacteria. The presented model structure and parameters successfully fit the measured data; however they do not necessarily reflect the only and true selection mechanism for Microthrix. This model is not yet to be used for prediction; it is rather a valuable research tool to coordinate the discussion and plan future research activities in order to identify the relevant selection mechanisms favoring Microthrix in activated sludge systems.
authors.affiliation: Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, PO Box 611, CH-8600 Duebendorf, Switzerland. thomas.hug@eawag.ch
authors.forename: T
authors.initials: T
authors.lastname: Hug
authors.forename: W
authors.initials: W
authors.lastname: Gujer
authors.forename: H
authors.initials: H
authors.lastname: Siegrist
mesh_terms: D039903:Actinobacteria / Q000502:physiology*; D002138:Calibration; D017404:In Situ Hybridization, Fluorescence; D007220:Industrial Waste; D007700:Kinetics; D008962:Models, Theoretical; D012621:Seasons
chemical_list: D007220:Industrial Waste