Diversity, dynamics and activity of Epsilonproteobacteria in a stratified karstic lake. Implications in carbon and sulfur cycles

Noguerola Solà, Imma
This doctoral thesis studies the abundance, diversity, seasonal dynamics and activity of Epsilonproteobacteria in a meromictic basin of Lake Banyoles during three year cycles. We applied a complementary array of molecular techniques to resolve the identity and ecological role of Epsilonproteobacteria in the system, with special focus on the contribution of these microorganisms on linking C and S cycles. Our results pointed to a clear seasonality of Epsilonproteobacteria, with maximal abundances at the redoxcline and upper monimolimnion in winter. Furthermore, results revealed the predominance of sequences affiliated to genus Arcobacter, and clearly indicated that Epsilonproteobacteria actively assimilated CO2 in the dark thus being responsible of the high rates of dark carbon fixation measured at the redoxcline in winter. Additional analyses provided additional evidence that the dominant member of the epsilonproteobacterial community is a chemolithotrophic, sulfide-oxidizing member of the genus Arcobacter, distantly related to its marine counterpart Candidatus A.sulfidicus. ​
​L'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc/4.0/