title: Membrane bioreactor wastewater treatment plants reveal diverse yeast and protist communities of potential significance in biofouling.
abstract: The yeast community was studied in a municipal full-scale membrane bioreactor wastewater treatment plant (MBR-WWTP). The unexpectedly high diversity of yeasts indicated that the activated sludge formed a suitable environment for them to proliferate, with cellular concentrations of 2.2 ± 0.8 × 10(3) CFU ml(-1). Sixteen species of seven genera were present in the biological reactor, with Ascomycetes being the most prevalent group (93%). Most isolates were able to grow in a synthetic wastewater medium, adhere to polyethylene surfaces, and develop biofilms of variable complexity. The relationship between yeast populations and the protists in the MBR-WWTP was also studied, revealing that some protist species preyed on and ingested yeasts. These results suggest that yeast populations may play a role in the food web of a WWTP and, to some extent, contribute to membrane biofouling in MBR systems.
authors.affiliation: a Department of Microbiology III , Complutense University , Madrid , Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Liébana
authors.forename: Lucía
authors.initials: L
authors.lastname: Arregui
authors.forename: Ignacio
authors.initials: I
authors.lastname: Belda
authors.forename: Luis
authors.initials: L
authors.lastname: Gamella
authors.forename: Antonio
authors.initials: A
authors.lastname: Santos
authors.forename: Domingo
authors.initials: D
authors.lastname: Marquina
authors.forename: Susana
authors.initials: S
authors.lastname: Serrano
mesh_terms: D018441:Biofilms; D057219:Biofouling; D019149:Bioreactors / Q000382:microbiology*; D016812:Euplotes; D010247:Paramecium; D010802:Phylogeny; D020959:Polyethylene; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000382:microbiology; D015003:Yeasts / Q000302:isolation & purification*
chemical_list: D020959:Polyethylene; D012722:Sewage; D062065:Wastewater
keywords: biofouling; membrane bioreactor; predation; protists; wastewater treatment; yeast biofilms