Ciliate contributions to bioaggregationlaboratory assays with axenic cultures of "Tetrahymena thermophila"

  1. Lucía Arregui
  2. Susana Serrano
  3. María Linares
  4. Blanca Pérez Uz
  5. Almudena Guinea
Revista:
International microbiology: official journal of the Spanish Society for Microbiology

ISSN: 1618-1905

Año de publicación: 2007

Volumen: 10

Número: 2

Páginas: 91-96

Tipo: Artículo

Otras publicaciones en: International microbiology: official journal of the Spanish Society for Microbiology

Resumen

Protists, mainly ciliates, play several essential roles in biological wastewater treatment, such as the transfer of matter and energy, bacterial predation, and the removal of organic material. Moreover, during the treatment process, the formation of bioaggregates -flocs and biofilms- is essential to obtaining high-quality effluents. In the present study, Tetrahymena thermophila was used as a model organism to demonstrate the contribution of ciliates to bioflocculation. Axenic cultures of this species were exposed to chemical and mechanical stimuli that promote bioaggregation. In either case, the secretion of a capsulate mucous material by the ciliates or by particle aggregation was detected. Numerous, small, loosely compacted flocs were observed under shaking conditions and in the presence of latex beads. The composition of the exopolymeric material secreted by ciliates was analyzed by a series of fluorochromes and colorimetric methods, which showed that carbohydrates and nucleic acids were the main components involved in matrix formation and particle adhesion.