Function and structure of river sediment biofilms and their role in dissolved organic matter utilization

• Autores: Anna Freixa Casals
• Directores de la Tesis: Anna M. Romaní (dir. tes.)
• Lectura: En la Universitat de Girona ( España ) en 2016
• Idioma: inglés
• Tribunal Calificador de la Tesis: Maria Montserrat Sala Farré (presid.), Silke Langenheder (secret.), Martin Rulik (voc.)
• Programa de doctorado: Programa Oficial de Doctorado en Ciencias Experimentales y Sostenibilidad
• Materias:
  • Ciencias de la vida
    • Microbiología
      • Metabolismo bacteriano
      • Metabolismo microbiano
  • Ciencias de la tierra y del espacio
    • Hidrología
      • Limnología
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • The objective of this thesis was to study how sediment microbial communities in Mediterranean rivers used dissolved organic matter at different spatial and temporal scales. Results from the two field studies, showed that the quality and origin of the dissolved organic matter (allochthonous versus autochthonous) and the different hydrological periods (drought versus base flow) highly modified the biofilm functioning and composition. On the other hand, the two laboratory experiments showed that first, the decrease in dissolved oxygen in sediment depth determined the microbial organic matter degradation. And second, results also showed that warming river water increased the heterotrophy of the microbial communities and clearly modified the food web structure. In conclusion this thesis demonstrates that the structure and functioning of sediment biofilms change at different spatial and temporal scales and they are sensitive to the increase in water pollution and the effects of global climate change.