title: Interlinkages between bacterial populations dynamics and the operational parameters in a moving bed membrane bioreactor treating urban sewage.
abstract: Bacteria are key players in biological wastewater treatments (WWTs), thus a firm knowledge of the bacterial population dynamics is crucial to understand environmental/operational factors affecting the efficiency and stability of the biological depuration process. Unfortunately, little is known about the microbial ecology of the advanced biological WWTs combining suspended biomass (SB) and attached biofilms (AB). This study explored in depth the bacterial community structure and population dynamics in each biomass fraction from a pilot-scale moving bed membrane bioreactor (MBMBR) treating municipal sewage, by means of temperature-gradient gel electrophoresis (TGGE) and 454-pyrosequencing. Eight experimental phases were conducted, combining different carrier filling ratios, hydraulic retention times and concentrations of mixed liquor total suspended solids. The bacterial community, dominated by Proteobacteria (20.9-53.8%) and Actinobacteria (20.6-57.6%), was very similar in both biomass fractions and able to maintain its functional stability under all the operating conditions, ensuring a successful and steady depuration process. Multivariate statistical analysis demonstrated that solids concentration, carrier filling ratio, temperature and organic matter concentration in the influent were the significant factors explaining population dynamics. Bacterial diversity increased as carrier filling ratio increased (from 20% to 35%, v/v), and solids concentration was the main factor triggering the shifts of the community structure. These findings provide new insights on the influence of operational parameters on the biology of the innovative MBMBRs.
authors.affiliation: Departamento de Microbiología, Facultad de Farmacia, Universidad de Granada, 18071 Granada, Spain; Instituto del Agua, Universidad de Granada, 18071 Granada, Spain. Electronic address: preboleiro@ugr.es.
authors.forename: P
authors.initials: P
authors.lastname: Reboleiro-Rivas
authors.affiliation: Departamento de Ingeniería Civil, Universidad de Granada, 18071 Granada, Spain; Instituto del Agua, Universidad de Granada, 18071 Granada, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Martín-Pascual
authors.affiliation: Instituto del Agua, Universidad de Granada, 18071 Granada, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Morillo
authors.affiliation: Departamento de Microbiología, Facultad de Farmacia, Universidad de Granada, 18071 Granada, Spain; Instituto del Agua, Universidad de Granada, 18071 Granada, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Juárez-Jiménez
authors.affiliation: Departamento de Ingeniería Civil, Universidad de Granada, 18071 Granada, Spain; Instituto del Agua, Universidad de Granada, 18071 Granada, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Poyatos
authors.affiliation: Departamento de Microbiología, Facultad de Farmacia, Universidad de Granada, 18071 Granada, Spain; Instituto del Agua, Universidad de Granada, 18071 Granada, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Rodelas
authors.affiliation: Departamento de Microbiología, Facultad de Farmacia, Universidad de Granada, 18071 Granada, Spain; Instituto del Agua, Universidad de Granada, 18071 Granada, Spain.
authors.forename: J
authors.initials: J
authors.lastname: González-López
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000235:genetics; D019149:Bioreactors; D008567:Membranes, Artificial; D015999:Multivariate Analysis; D010802:Phylogeny; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid
chemical_list: D001426:Bacterial Proteins; D008567:Membranes, Artificial; D012722:Sewage
keywords: 454-Pyrosequencing; Bacterial populations dynamics; Moving bed membrane bioreactor; Multivariate statistical analysis; TGGE